Kolb-Archive.digest.vol-ns
March 16, 2016 - March 22, 2016
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Wed, 3/16/16, Rick Neilsen wrote:
Subject: Re: Kolb-List: FireStar 2 Kit Received !
To: "kolb-list(at)matronics.com"
Date: Wednesday, March 16, 2016, 12:49 PM
Bill
Consider that new engine very carefully. I'm
speaking from experience. I was the first to put a VW on a
Kolb. It is a big undertaking. First thePegasus Power O-100 engine uses a difocalmount
and kolbs have a bed type mount. I had tofabricatea
custom mount for the VW. I had help as GP Aircraft made a
prop end mount that made iteasier. You will have to
fabricate a custom exhaustsystem. You will need to enter
the black science of prop selection. You may likemagnetos
but I don't, they are heavy, expensive, under powered,
and there is a reason they come in pairs.Now the real
tough stuff, the engine is still in development. You will be
the test pilot for not just the engine installation but for
the engine too.
Don't get me wrong I'm not trying to talk
you out of it but do not underestimate the task you will be
taking on. I spent one extra year installing my VW. Then
Ichangedto a redriveVW engine. Then I had a redrive
failure. Then Ifabricateda new lower engine mount. Five
years later I was stilltweakingexhaustsystems, Props,
carb settings, and redrive ratios. Eighteen years later
I'm stillbattlingengine noise - the engine
mounttransmitstoo much vibration noise to the airframe.
One of my high engine mounts had a soft enough mount that
was very smooth and quiet but chewed up engine mounting
bushings/dampers.
One more thing, engine
buildersoverestimatepower and underestimate weight and
price.
It could be a worthychallenge but are you up to
it?
Rick NeilsenRedrive VW
Powered MKIIIC
On Wed, Mar 16, 2016
at 1:33 PM, Bill Berle
wrote:
Bill Berle
Well, the used FS2 kit that I had purchased has arrived! I
picked it up form the Yellow Freight terminal (YRC nowdays)
last night. Got it back to my hangar, and was able to spend
a couple of hours unpacking most of it. I have not been able
to do a full inventory, because I do not have a full
inventory sheet from Kolb. But I have a lot of various
airplane hardware floating around in my hangar :)
One of the chimpanzees involved somewhere in the shipping
crushed two or three small tubes in the horizontal
stabilizers.
The fuselage cage had been hand-painted with white brush-on
house paint or something. I'm thankful for that, because
there is only minor corrosion in the form of brown stains in
the white paint, and no serious pitting. I will eventually
have it blasted and re-primed or powder coated. Any
suggestions, warnings, or experience good or bad with powder
coating and steel priming is welcome.
The kit came with brownish-red plastic wheels and 15 x 6.00
x 6 tires. Alumuinum gear legs, short windshield, one gas
can. It is serial number FS-636, the instruction manual is
dated 1996.
The aluminum tube for the tailboom ("fuselage
tube" in Kolb language) had apparently been
accidentally drilled for the wing ribs, because the original
builder did not realize the tubes were different. So I may
be able to salvage it, repair it, or plug the holes with
"Dead" rivets. Or, I may have to replace the
tube.
I will be using 4 stroke power on this, as I have mentioned
previously. Dagwodzz has been very kind to spend some
quality time with me on the phone educating me about
V-twins. Thank you Dagz! I am also looking at the absolutely
beautiful Pegasus Power O-100 engine from Pete Plumb in
California. I have seen this engine run in person and was
very very impressed.
If anyone can point me to specific articles or archives on
this list regarding technical errors in the plans or
instructions, or common problems building the FireStar,
Again I am happy to hear about it.
I have several minor and medium size modifications and
tweaks that I am looking into on this airplane. Some of them
are aerodynamic (raked tips, VG's, etc.), some of them
are engine related (4 stroke), and some of them are
mechanical (aircraft quality hardware and fasteners wherever
possible... I have this stuff laying around).
Glad to be a brand new, green, wet-behind-the-ears Kolber !
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and for-profit
entities
--------------------------------------------
On Tue, 3/15/16, Richard Girard
wrote:
Subject: Re: Kolb-List: Re: Tires for your Firestar
To: "kolb-list(at)matronics.com"
Date: Tuesday, March 15, 2016, 9:21 AM
you could also try
this. I've never used it, can't make a
recommendation.
https://www.zoro.com/3m-flexible-foam-nvh-08463/i/G0406463/?gdffi=047ada998cf641fa93e55ae8579df863&gdfms=5EA4232146CF4B229C255AAAF651CF33&gclid=CPW8-dyLw8sCFQYIaQodCZwIjw&gclsrc=aw.ds
Lots of Youtube videos about using urethane foam
to fill tires, too, but it doesn't remain flexible so
it'll crush up over time and make a mess in something
like an aircraft tire.
Rick
On Mon, Mar 14, 2016
at 1:08 PM, Bill Berle
wrote:
Bill Berle
Here's a potential game-changer solution right
here...
http://www.goldspeedproducts.com/shop/tire-blocks/
These are foam inserts that allow you to run lower
pressure
and even run safely when punctured flat.
I'll bet that these foam blocks weigh less than the
three piece tire iron set that was mentioned earlier, or
the
can of flat tire repair goop :)
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and
for-profit
entities
--------------------------------------------
On Mon, 3/14/16, Larry Cottrell
wrote:
Subject: Re: Kolb-List: Re: Tires for your Firestar
To: "kolb-list(at)matronics.com"
Date: Monday, March 14, 2016, 10:37 AM
"
I
will have a small lightweight tool kit with me, and a
tire
pump. Even on a certified172 I can take the wheel off
the
airplane with a medium Crescent wrench, take the wheel
apart
with three 1/4 inch bolts, replace an inner tube or
patch
a
tire, and get it back together to fly back
home."
I just
carry a can of "spare tire" wrapped in bubble
wrap
in the back of my plane.
Larry
On Mon, Mar 14, 2016
at 10:56 AM, Bill Berle
wrote:
Bill Berle
Yes, I want to make it clear that I'm not trying to
hassle or trash-talk anyone or their product. I do
prefer
not having to wrestle with someone just to get an
answer
to
my question, but regardless of the effort it takes to
get
that answer my motives and agendas are positive and not
negative.
My situation is that I want to fly extreme-STOL up in
the
mountains and desert. I've been scouting several
locations in my 172, and believe it or not most of them
are
actually within 50 or 60 miles of the "big
city"
limits. So it's not like I'm going out Grizzly
bear
bow hunting in the Aleutian Islands or anything... but
it's still way too far for me to just "walk
into
town" with a tire and wheel in my hands.
I will have a small lightweight tool kit with me, and a
tire
pump. Even on a certified172 I can take the wheel off
the
airplane with a medium Crescent wrench, take the wheel
apart
with three 1/4 inch bolts, replace an inner tube or
patch
a
tire, and get it back together to fly back home.
Bill Berle
--------------------------------------------
On Mon, 3/14/16, Richard Girard
wrote:
Subject: Re: Kolb-List: Re: Tires for your Firestar
To: "kolb-list(at)matronics.com"
Date: Monday, March 14, 2016, 9:29 AM
I have three metal
tire irons that I carry with me. Less than 1 lb. for
the
set
and with a little water as lubricant they get the
tire
off
a
one piece wheel just fine. It's breaking the bead
that's the trick and for that I just use a hammer
with
one iron to get it started. It's not what I'd
use
at
home, but we're talking stranded in the outback
with
the
vultures circling. :-}
Rick Girard
On Mon, Mar 14, 2016
at 9:16 AM, Charlie England
wrote:
Charlie England
The tires and wheels do look nice, and are likely a
good
option if flying close to home.
However, it seems like you're missing his point.
He's talking about real 'bush' flying,
away
from
airports & service facilities. With conventional
2
piece
wheels, you could break them down with simple hand
tools
to
repair a flat, and a small hand pump to re-inflate.
But
with
auto-style one piece wheels, it requires specialized
(heavy)
tools to break a tire down for repair. Not likely to
be
in
a
tool kit you can carry in a Kolb or other very light
a/c.
Charlie
On 3/13/2016 11:19 PM, Carolina Flyer wrote:
Flyer"
Bill, I use a cheap harbor freight device for
putting
the
tires on, cost $49.95 I think.
Rick, The only tires that I sell are these that I
have
pictures of and they fit on a 8 inch rims
--------
Kolb Firestar II
503 C-Box / RK400
Soon to have a
Rotax 670 DCDI
with a C-Box and
RK 400 Clutch
Challenger II
503 Tall Drive
Location : Buffalo South Carolina
==========
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fts!)
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Blessed
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Groucho
Marx
==========
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fts!)
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>
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If you forward this email, or any part of
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==========
br>
fts!)
r>
>
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target="_blank">www.buildersbooks.com
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
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-Matt Dralle, List Admin.
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
==========
--
Blessed
are the cracked, for they shall let in the light.
Groucho
Marx
==========
br>
fts!)
r>
>
w.buildersbooks.com" rel="noreferrer"
target="_blank">www.buildersbooks.com
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
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==========
________________________________________________________________________________
| Subject: | Re: Fixing a Flat Tire |
| From: | Rick Neilsen <neilsenrm(at)gmail.com> |
Dennis
On a trip to Airventure I had a flat after a overnight stop. In the morning
I filled my tire with a can of Fix-A-Flat. I got to my next fuel stop and
added a bit more air. On the next stop I landed at Airventure with a
totally flat tire.
Rick Neilsen
Redrive VW Powered MKIIIC
On Wed, Mar 16, 2016 at 3:03 PM, KIRBY, DENNIS T GS-13 USAF AFMC AFNWC/EZS <
dennis.kirby.3(at)us.af.mil> wrote:
> AFNWC/EZS"
>
> Bill Berle wrote: << I will have a small lightweight tool kit with me, and
> a tire pump. I can take the wheel off the airplane with a medium Crescent
> wrench,
> take the wheel apart with three 1/4 inch bolts, replace an inner tube or
> patch
> a tire, and get it back together to fly back home. >
>
>
> Bill / Kolb Friends -
>
> I, too, travel with tire changing tools in my Mark-3 when I go backcountry
> flying. As Bill describes above, I am able to remove and take apart my
> split rims and patch (or replace) the inner tube.
>
> But what about using "Fix-a-Flat" for the solution? Does anyone have
> experience blasting this goop into their Kolb inner tubes to remedy a flat
> tire? Seems a lot lighter and easier, and you don't need the tire pump.
>
> Pros? Cons?
>
> Dennis Kirby
> Mark-3
> New Mexico
>
>
________________________________________________________________________________
| Subject: | Re: FireStar 2 Kit Received ! |
| From: | Rick Neilsen <neilsenrm(at)gmail.com> |
John
The way the sun hits her she looks like she is smiling.
Rick
On Wed, Mar 16, 2016 at 4:05 PM, John Hauck wrote:
>
>
> Homer Kolb designed his wing for a reason. It works.
>
> I have never, in 32 years changed the outside dimensions of an Ultrastar,
> Firestar, or MKIII wing. They work for me.
>
> Plastic wheels don't even make good paper weights.
>
> A varmint decided to taste the fabric on the right main gear of my MKIII.
> We just completely rebuilt, fabric and paint, both main gear a year ago.
> I'd shoot him is I could find him. Have no idea what it was. I was over
> at Gantt International Airport yesterday taking photos of the damage. To
ok
> a couple extra of the environment over there. My little piece of heaven.
>
> Spring has sprung at hauck's holler. The weeds have sprouted. One can
> watch them grow they are so fast. Spring is my favorite season.
> Everything is already covered with pollen. ;-)
>
>
> john h
> mkIII
> Titus, Alabama
>
>
> -----Original Message-----
> From: owner-kolb-list-server(at)matronics.com [mailto:
> owner-kolb-list-server(at)matronics.com] On Behalf Of Bill Berle
> Sent: Wednesday, March 16, 2016 12:33 PM
> To: kolb-list(at)matronics.com
> Subject: Re: Kolb-List: FireStar 2 Kit Received !
>
>
> Well, the used FS2 kit that I had purchased has arrived! I picked it up
> form the Yellow Freight terminal (YRC nowdays) last night. Got it back to
> my hangar, and was able to spend a couple of hours unpacking most of it.
I
> have not been able to do a full inventory, because I do not have a full
> inventory sheet from Kolb. But I have a lot of various airplane hardware
> floating around in my hangar :)
>
> One of the chimpanzees involved somewhere in the shipping crushed two or
> three small tubes in the horizontal stabilizers.
>
> The fuselage cage had been hand-painted with white brush-on house paint o
r
> something. I'm thankful for that, because there is only minor corrosion i
n
> the form of brown stains in the white paint, and no serious pitting. I wi
ll
> eventually have it blasted and re-primed or powder coated. Any suggestion
s,
> warnings, or experience good or bad with powder coating and steel priming
> is welcome.
>
> The kit came with brownish-red plastic wheels and 15 x 6.00 x 6 tires.
> Alumuinum gear legs, short windshield, one gas can. It is serial number
> FS-636, the instruction manual is dated 1996.
>
> The aluminum tube for the tailboom ("fuselage tube" in Kolb language) had
> apparently been accidentally drilled for the wing ribs, because the
> original builder did not realize the tubes were different. So I may be ab
le
> to salvage it, repair it, or plug the holes with "Dead" rivets. Or, I may
> have to replace the tube.
>
> I will be using 4 stroke power on this, as I have mentioned previously.
> Dagwodzz has been very kind to spend some quality time with me on the pho
ne
> educating me about V-twins. Thank you Dagz! I am also looking at the
> absolutely beautiful Pegasus Power O-100 engine from Pete Plumb in
> California. I have seen this engine run in person and was very very
> impressed.
>
> If anyone can point me to specific articles or archives on this list
> regarding technical errors in the plans or instructions, or common proble
ms
> building the FireStar, Again I am happy to hear about it.
>
> I have several minor and medium size modifications and tweaks that I am
> looking into on this airplane. Some of them are aerodynamic (raked tips,
> VG's, etc.), some of them are engine related (4 stroke), and some of them
> are mechanical (aircraft quality hardware and fasteners wherever
> possible... I have this stuff laying around).
>
> Glad to be a brand new, green, wet-behind-the-ears Kolber !
>
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and
> for-profit entities
>
> --------------------------------------------
> On Tue, 3/15/16, Richard Girard wrote:
>
> Subject: Re: Kolb-List: Re: Tires for your Firestar
> To: "kolb-list(at)matronics.com"
> Date: Tuesday, March 15, 2016, 9:21 AM
>
> you could also try
> this. I've never used it, can't make a
> recommendation.
>
> https://www.zoro.com/3m-flexible-foam-nvh-08463/i/G0406463/?gdffi=047ad
a998cf641fa93e55ae8579df863&gdfms=5EA4232146CF4B229C255AAAF651CF33&gclid
=CPW8-dyLw8sCFQYIaQodCZwIjw&gclsrc=aw.ds
>
> Lots of Youtube videos about using urethane foam to fill tires, too, bu
t
> it doesn't remain flexible so it'll crush up over time and make a mess i
n
> something like an aircraft tire.
> Rick
> On Mon, Mar 14, 2016
> at 1:08 PM, Bill Berle
> wrote:
> Bill Berle
>
>
> Here's a potential game-changer solution right here...
>
>
> http://www.goldspeedproducts.com/shop/tire-blocks/
>
>
> These are foam inserts that allow you to run lower pressure and even ru
n
> safely when punctured flat.
>
>
> I'll bet that these foam blocks weigh less than the three piece tire
> iron set that was mentioned earlier, or the can of flat tire repair goop
:)
>
>
> Bill Berle
>
> www.ezflaphandle.com
> - safety & performance upgrade for light aircraft
>
> www.grantstar.net
> - winning proposals for non-profit and for-profit entities
>
>
> --------------------------------------------
>
> On Mon, 3/14/16, Larry Cottrell
>
> wrote:
>
>
> Subject: Re: Kolb-List: Re: Tires for your Firestar
>
> To: "kolb-list(at)matronics.com"
>
>
> Date: Monday, March 14, 2016, 10:37 AM
>
>
> "
>
> I
>
> will have a small lightweight tool kit with me, and a tire
>
> pump. Even on a certified172 I can take the wheel off the
>
> airplane with a medium Crescent wrench, take the wheel apart
>
> with three 1/4 inch bolts, replace an inner tube or patch a
>
> tire, and get it back together to fly back
>
> home."
>
>
> I just
>
> carry a can of "spare tire" wrapped in bubble wrap
>
> in the back of my plane.
>
> Larry
>
> On Mon, Mar 14, 2016
>
> at 10:56 AM, Bill Berle
>
> wrote:
>
>
> Bill Berle
>
>
> Yes, I want to make it clear that I'm not trying to
>
> hassle or trash-talk anyone or their product. I do prefer
>
> not having to wrestle with someone just to get an answer to
>
> my question, but regardless of the effort it takes to get
>
> that answer my motives and agendas are positive and not
>
> negative.
>
>
> My situation is that I want to fly extreme-STOL up in the
>
> mountains and desert. I've been scouting several
>
> locations in my 172, and believe it or not most of them are
>
> actually within 50 or 60 miles of the "big city"
>
> limits. So it's not like I'm going out Grizzly bear
>
> bow hunting in the Aleutian Islands or anything... but
>
> it's still way too far for me to just "walk into
>
> town" with a tire and wheel in my hands.
>
>
> I will have a small lightweight tool kit with me, and a tire
>
> pump. Even on a certified172 I can take the wheel off the
>
> airplane with a medium Crescent wrench, take the wheel apart
>
> with three 1/4 inch bolts, replace an inner tube or patch a
>
> tire, and get it back together to fly back home.
>
>
> Bill Berle
>
>
> --------------------------------------------
>
>
> On Mon, 3/14/16, Richard Girard
>
> wrote:
>
>
> Subject: Re: Kolb-List: Re: Tires for your Firestar
>
>
> To: "kolb-list(at)matronics.com"
>
>
>
>
> Date: Monday, March 14, 2016, 9:29 AM
>
>
> I have three metal
>
>
> tire irons that I carry with me. Less than 1 lb. for the
>
> set
>
>
> and with a little water as lubricant they get the tire off
>
> a
>
>
> one piece wheel just fine. It's breaking the bead
>
>
> that's the trick and for that I just use a hammer
>
> with
>
>
> one iron to get it started. It's not what I'd use
>
> at
>
>
> home, but we're talking stranded in the outback with
>
> the
>
>
> vultures circling. :-}
>
>
> Rick Girard
>
>
> On Mon, Mar 14, 2016
>
>
> at 9:16 AM, Charlie England
>
>
> wrote:
>
>
> Charlie England
>
>
> The tires and wheels do look nice, and are likely a good
>
>
> option if flying close to home.
>
>
> However, it seems like you're missing his point.
>
>
> He's talking about real 'bush' flying, away
>
> from
>
>
> airports & service facilities. With conventional 2
>
> piece
>
>
> wheels, you could break them down with simple hand tools
>
> to
>
>
> repair a flat, and a small hand pump to re-inflate. But
>
> with
>
>
> auto-style one piece wheels, it requires specialized
>
> (heavy)
>
>
> tools to break a tire down for repair. Not likely to be in
>
> a
>
>
> tool kit you can carry in a Kolb or other very light
>
>
> a/c.
>
>
> Charlie
>
>
> On 3/13/2016 11:19 PM, Carolina Flyer wrote:
>
>
> Flyer"
>
>
> Bill, I use a cheap harbor freight device for putting
>
> the
>
>
> tires on, cost $49.95 I think.
>
>
> Rick, The only tires that I sell are these that I have
>
>
> pictures of and they fit on a 8 inch rims
>
>
> --------
>
>
> Kolb Firestar II
>
>
> 503 C-Box / RK400
>
>
> Soon to have a
>
>
> Rotax 670 DCDI
>
>
> with a C-Box and
>
>
> RK 400 Clutch
>
>
> Challenger II
>
>
> 503 Tall Drive
>
>
> Location : Buffalo South Carolina
>
>
> ==========
>
>
> br>
>
>
> fts!)
>
>
> r>
>
>
> >
>
>
> href="http://www.buildersbooks.com"
>
>
> rel="noreferrer"
>
>
> target="_blank">www.buildersbooks.com
>
>
> rel="noreferrer"
>
>
> target="_blank">http://www.matronics.com/contribution
>
>
> -Matt Dralle, List Admin.
>
>
> ==========
>
>
> -List" rel="noreferrer"
>
>
> target="_blank">http://www.matronics.com/Navigator?Kolb-List
>
>
> ==========
>
>
> FORUMS -
>
>
> eferrer"
>
>
> target="_blank">http://forums.matronics.com
>
>
> ==========
>
>
> b Site -
>
>
> -Matt Dralle, List Admin.
>
>
> rel="noreferrer"
>
>
> target="_blank">http://www.matronics.com/contribution
>
>
> ==========
>
>
> --
>
>
> =9CBlessed
>
>
> are the cracked, for they shall let in the light.=9D
>
> Groucho
>
>
> Marx
>
>
> ==========
>
>
> br>
>
> fts!)
>
>
> r>
>
> >
>
> w.buildersbooks.com"
> rel="noreferrer"
>
> target="_blank">www.buildersbooks.com
>
>
> rel="noreferrer"
>
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>
> FORUMS -
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>
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>
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>
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>
> The older I get, the less tolerant I am of
>
> those who are intolerant.
>
> If you forward this email, or any part of
>
> it, please remove my email address before sending.
>
>
> ==========
>
> br>
> fts!)
>
> r>
> >
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> target="_blank">www.buildersbooks.com
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
>
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> -List" rel="noreferrer"
> target="_blank">http://www.matronics.com/Navigator?Kolb-List
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> ==========
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>
> eferrer"
> target="_blank">http://forums.matronics.com
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> target="_blank">http://www.matronics.com/contribution
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> --
> =9CBlessed
> are the cracked, for they shall let in the light.=9D Groucho Ma
rx
>
>
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | Re: FireStar 2 Kit Received ! |
"Homer Kolb designed his wing for a reason. It works.
I have never, in 32 years changed the outside dimensions of
an Ultrastar, Firestar, or MKIII wing. They work for
me."
I agree completely, I'm sure the stock Kolb wing works perfectly well. But on an
experimental homebuilt I'm looking to add some of the small amount of knowledge
and experience that I've gained through about the same 30+ years in aviation.
Mr. Kolb himself changed the wing dimensions to create the Slingshot, Kolbra, Firelfy,
and others. He also changed the angle of incidence (wing mounting angle)
to create different characteristics on different models.
Raked wingtips are shown to work, especially at high AoA and low speeds. They create
a pressure field that slightly reduces the wingtip vortex.
VG's are shown to work great, especially on simple turbulent flow airfoils like
the Cub, Kolb, and Aeronca. They help the airflow stay attached to the wing at
higher AoA. This results in better control authority at low speeds, which will
be a lifesaver in off-airport STOL operations.
On a high drag airplane like a Kolb, reducing drag doesn't make you go any faster.
It allows you to fly at the same speed with less power or fuel burn.
Mr. Kolb designed the landing gear to be as easy and low-risk for new or low-time
pilots as possible. It worked, and the Kolb has a wonderful reputation for
easy ground handling. This is just what the doctor ordered for a kit plane that
was safe for low time pilots. But this mellow ground handling comes at the
cost of losing the ideal ground angle for the wing to take off and land slower.
A longer or taller landing gear requires a slightly more experienced pilot,
but you get better STOL performance in the bargain.
________________________________________________________________________________
| From: | "Rex Rodebush" <jrrodebush(at)gmail.com> |
Attached are pictures of the brake pedals I modified to fit my feet.
I bought new Matco wheels about 2 years ago as they are thicker and Matco had
cracking problems with the old ones. I ordered the new machined caliper with
the wheels as they have a larger piston than the old cast versions. The braking
was better but still not acceptable. I then mounted the old calipers on in
addition as the wheels were drilled for dual calipers and the mounting holes
were the same.
Now the braking is great.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=453823#453823
Attachments:
http://forums.matronics.com//files/brakes2_167.jpg
http://forums.matronics.com//files/brakes1_204.jpg
________________________________________________________________________________
| From: | Dennis Rowe <rowedenny(at)windstream.net> |
| Subject: | Re: FireStar 2 Kit Received ! |
If the following statement is true, you'll want an HKS700e
Dennis "Skid" Rowe
>
> I just know that I'm more comfortable with 4 stroke power, and I want the reliability/noise
benefits of those engines.
>
> Bill
________________________________________________________________________________
| From: | "John Hauck" <jhauck(at)elmore.rr.com> |
| Subject: | FireStar 2 Kit Received ! |
Bill B/Kolbers:
With your background you should realize what it takes to "make" an airplane engine,
and make it work safely and reliably, while making more power than ever required.
Takes but a minute to discover Rotax 2 and 4 stroke engines, a couple VW's, and
a smattering of HKS's are what is pushing Kolbs though the air. Since this thing
started about 40 years ago, there have been a lot of different power plants
tried, but it comes down to the few I mentioned that are still around and still
flying.
I had a buddy, back in the 80's, that had a J3 Kitten powered with a half VW, a
4 stroke. At the time I was flying my FS with a 447. He was always bragging
about how much more reliable his 4 stroke was than my 2 stroke. Of course, he
had never had an engine stoppage or failure, and I had had plenty of both.
One day we were flying a cross country from Bessemer to Wetumpka, AL. We were
chatting on the radio when my buddy said, "Uh oh!", as the Kitten rapidly descended
into a farmer's field. His 4 stroke had broken a valve spring.
All these engines, 2 and 4 stroke will quit when they get ready, for one reason
or the other. When I fly places that I cannot survive if I have an engine out,
I say a little prayer to my Higher Power, and accept that fact if the engine
stops. At my age I am getting less inclined to take those chances, but it is
difficult to fly anywhere when you, at some time during that flight, don't find
yourself in that situation.
Some folks thrive on developing and experimenting with our airplanes. That is
what keeps them going. We have all done our share over the years. So get out
there and get a new engine going that is safe, reliable, more power than ever
needed, cheap, and burns 1 GPH.
Time to roll out the MKIII and get the pollen and barn dust washed off her.
john h
mkIII
Titus, Alabama
-----Original Message-----
From: owner-kolb-list-server(at)matronics.com [mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Bill Berle
Sent: Wednesday, March 16, 2016 3:12 PM
Subject: Re: Kolb-List: FireStar 2 Kit Received !
Thanks Rick,
I'm not taking it lightly. I have started to look at just what it would take to
adapt the O-100 engine, and yes it is completely different than the Rotax bed
mount built into the airframe.
I happen to be very fortunate in that I have a good infrastructure of structural
engineering, welding, machinists, and fabricators available to me. I could never
take this on without having built up that infrastructure.
I just know that I'm more comfortable with 4 stroke power, and I want the reliability/noise
benefits of those engines.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Wed, 3/16/16, Rick Neilsen wrote:
Subject: Re: Kolb-List: FireStar 2 Kit Received !
To: "kolb-list(at)matronics.com"
Date: Wednesday, March 16, 2016, 12:49 PM
Bill
Consider that new engine very carefully. I'm speaking from experience. I was
the first to put a VW on a Kolb. It is a big undertaking. First the Pegasus Power
O-100 engine uses a difocal mount and kolbs have a bed type mount. I had
to fabricate a custom mount for the VW. I had help as GP Aircraft made a prop
end mount that made it easier. You will have to fabricate a custom exhaust
system. You will need to enter the black science of prop selection. You may
like magnetos but I don't, they are heavy, expensive, under powered, and there
is a reason they come in pairs. Now the real tough stuff, the engine is still
in development. You will be the test pilot for not just the engine installation
but for the engine too.
Don't get me wrong I'm not trying to talk you out of it but do not underestimate
the task you will be taking on. I spent one extra year installing my VW.
Then I changed to a redrive VW engine. Then I had a redrive failure. Then I
fabricated a new lower engine mount. Five years later I was still tweaking exhaust
systems, Props, carb settings, and redrive ratios. Eighteen years later
I'm still battling engine noise - the engine mount transmits too much vibration
noise to the airframe.
One of my high engine mounts had a soft enough mount that was very smooth and
quiet but chewed up engine mounting bushings/dampers. One more thing, engine
builders overestimate power and underestimate weight and price.
It could be a worthy challenge but are you up to it?
Rick NeilsenRedrive VW
Powered MKIIIC
On Wed, Mar 16, 2016
at 1:33 PM, Bill Berle
wrote:
Bill Berle
Well, the used FS2 kit that I had purchased has arrived! I
picked it up form the Yellow Freight terminal (YRC nowdays)
last night. Got it back to my hangar, and was able to spend
a couple of hours unpacking most of it. I have not been able
to do a full inventory, because I do not have a full
inventory sheet from Kolb. But I have a lot of various
airplane hardware floating around in my hangar :)
One of the chimpanzees involved somewhere in the shipping
crushed two or three small tubes in the horizontal
stabilizers.
The fuselage cage had been hand-painted with white brush-on
house paint or something. I'm thankful for that, because
there is only minor corrosion in the form of brown stains in
the white paint, and no serious pitting. I will eventually
have it blasted and re-primed or powder coated. Any
suggestions, warnings, or experience good or bad with powder
coating and steel priming is welcome.
The kit came with brownish-red plastic wheels and 15 x 6.00
x 6 tires. Alumuinum gear legs, short windshield, one gas
can. It is serial number FS-636, the instruction manual is
dated 1996.
The aluminum tube for the tailboom ("fuselage
tube" in Kolb language) had apparently been
accidentally drilled for the wing ribs, because the original
builder did not realize the tubes were different. So I may
be able to salvage it, repair it, or plug the holes with
"Dead" rivets. Or, I may have to replace the
tube.
I will be using 4 stroke power on this, as I have mentioned
previously. Dagwodzz has been very kind to spend some
quality time with me on the phone educating me about
V-twins. Thank you Dagz! I am also looking at the absolutely
beautiful Pegasus Power O-100 engine from Pete Plumb in
California. I have seen this engine run in person and was
very very impressed.
If anyone can point me to specific articles or archives on
this list regarding technical errors in the plans or
instructions, or common problems building the FireStar,
Again I am happy to hear about it.
I have several minor and medium size modifications and
tweaks that I am looking into on this airplane. Some of them
are aerodynamic (raked tips, VG's, etc.), some of them
are engine related (4 stroke), and some of them are
mechanical (aircraft quality hardware and fasteners wherever
possible... I have this stuff laying around).
Glad to be a brand new, green, wet-behind-the-ears Kolber !
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and for-profit
entities
--------------------------------------------
On Tue, 3/15/16, Richard Girard
wrote:
Subject: Re: Kolb-List: Re: Tires for your Firestar
To: "kolb-list(at)matronics.com"
Date: Tuesday, March 15, 2016, 9:21 AM
you could also try
this. I've never used it, can't make a
recommendation.
https://www.zoro.com/3m-flexible-foam-nvh-08463/i/G0406463/?gdffi=047ada998cf641fa93e55ae8579df863&gdfms=5EA4232146CF4B229C255AAAF651CF33&gclid=CPW8-dyLw8sCFQYIaQodCZwIjw&gclsrc=aw.ds
Lots of Youtube videos about using urethane foam
to fill tires, too, but it doesn't remain flexible so
it'll crush up over time and make a mess in something
like an aircraft tire.
Rick
On Mon, Mar 14, 2016
at 1:08 PM, Bill Berle
wrote:
Bill Berle
Here's a potential game-changer solution right
here...
http://www.goldspeedproducts.com/shop/tire-blocks/
These are foam inserts that allow you to run lower
pressure
and even run safely when punctured flat.
I'll bet that these foam blocks weigh less than the
three piece tire iron set that was mentioned earlier, or
the
can of flat tire repair goop :)
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and
for-profit
entities
--------------------------------------------
On Mon, 3/14/16, Larry Cottrell
wrote:
Subject: Re: Kolb-List: Re: Tires for your Firestar
To: "kolb-list(at)matronics.com"
Date: Monday, March 14, 2016, 10:37 AM
"
I
will have a small lightweight tool kit with me, and a
tire
pump. Even on a certified172 I can take the wheel off
the
airplane with a medium Crescent wrench, take the wheel
apart
with three 1/4 inch bolts, replace an inner tube or
patch
a
tire, and get it back together to fly back
home."
I just
carry a can of "spare tire" wrapped in bubble
wrap
in the back of my plane.
Larry
On Mon, Mar 14, 2016
at 10:56 AM, Bill Berle
wrote:
Bill Berle
Yes, I want to make it clear that I'm not trying to
hassle or trash-talk anyone or their product. I do
prefer
not having to wrestle with someone just to get an
answer
to
my question, but regardless of the effort it takes to
get
that answer my motives and agendas are positive and not
negative.
My situation is that I want to fly extreme-STOL up in
the
mountains and desert. I've been scouting several
locations in my 172, and believe it or not most of them
are
actually within 50 or 60 miles of the "big
city"
limits. So it's not like I'm going out Grizzly
bear
bow hunting in the Aleutian Islands or anything... but
it's still way too far for me to just "walk
into
town" with a tire and wheel in my hands.
I will have a small lightweight tool kit with me, and a
tire
pump. Even on a certified172 I can take the wheel off
the
airplane with a medium Crescent wrench, take the wheel
apart
with three 1/4 inch bolts, replace an inner tube or
patch
a
tire, and get it back together to fly back home.
Bill Berle
--------------------------------------------
On Mon, 3/14/16, Richard Girard
wrote:
Subject: Re: Kolb-List: Re: Tires for your Firestar
To: "kolb-list(at)matronics.com"
Date: Monday, March 14, 2016, 9:29 AM
I have three metal
tire irons that I carry with me. Less than 1 lb. for
the
set
and with a little water as lubricant they get the
tire
off
a
one piece wheel just fine. It's breaking the bead
that's the trick and for that I just use a hammer
with
one iron to get it started. It's not what I'd
use
at
home, but we're talking stranded in the outback
with
the
vultures circling. :-}
Rick Girard
On Mon, Mar 14, 2016
at 9:16 AM, Charlie England
wrote:
Charlie England
The tires and wheels do look nice, and are likely a
good
option if flying close to home.
However, it seems like you're missing his point.
He's talking about real 'bush' flying,
away
from
airports & service facilities. With conventional
2
piece
wheels, you could break them down with simple hand
tools
to
repair a flat, and a small hand pump to re-inflate.
But
with
auto-style one piece wheels, it requires specialized
(heavy)
tools to break a tire down for repair. Not likely to
be
in
a
tool kit you can carry in a Kolb or other very light
a/c.
Charlie
On 3/13/2016 11:19 PM, Carolina Flyer wrote:
Flyer"
Bill, I use a cheap harbor freight device for
putting
the
tires on, cost $49.95 I think.
Rick, The only tires that I sell are these that I
have
pictures of and they fit on a 8 inch rims
--------
Kolb Firestar II
503 C-Box / RK400
Soon to have a
Rotax 670 DCDI
with a C-Box and
RK 400 Clutch
Challenger II
503 Tall Drive
Location : Buffalo South Carolina
==========
br>
fts!)
r>
>
href="http://www.buildersbooks.com"
rel="noreferrer"
target="_blank">www.buildersbooks.com
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
==========
-List" rel="noreferrer"
target="_blank">http://www.matronics.com/Navigator?Kolb-List
==========
FORUMS -
eferrer"
target="_blank">http://forums.matronics.com
==========
b Site -
-Matt Dralle, List Admin.
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
==========
--
Blessed
are the cracked, for they shall let in the light.
Groucho
Marx
==========
br>
fts!)
r>
>
w.buildersbooks.com"
rel="noreferrer"
target="_blank">www.buildersbooks.com
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
==========
-List" rel="noreferrer"
target="_blank">http://www.matronics.com/Navigator?Kolb-List
==========
FORUMS -
eferrer"
target="_blank">http://forums.matronics.com
==========
b Site -
-Matt Dralle, List Admin.
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
==========
--
The older I get, the less tolerant I am of
those who are intolerant.
If you forward this email, or any part of
it, please remove my email address before sending.
==========
br>
fts!)
r>
>
w.buildersbooks.com"
rel="noreferrer"
target="_blank">www.buildersbooks.com
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
==========
-List" rel="noreferrer"
target="_blank">http://www.matronics.com/Navigator?Kolb-List
==========
FORUMS -
eferrer"
target="_blank">http://forums.matronics.com
==========
b Site -
-Matt Dralle, List Admin.
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
==========
--
Blessed
are the cracked, for they shall let in the light.
Groucho
Marx
==========
br>
fts!)
r>
>
w.buildersbooks.com" rel="noreferrer"
target="_blank">www.buildersbooks.com
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
==========
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target="_blank">http://www.matronics.com/Navigator?Kolb-List
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target="_blank">http://forums.matronics.com
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rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
==========
________________________________________________________________________________
| From: | "John Hauck" <jhauck(at)elmore.rr.com> |
| Subject: | FireStar 2 Kit Received ! |
She is smiling and ready to fly.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server(at)matronics.com
[mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Rick Neilsen
Sent: Wednesday, March 16, 2016 3:27 PM
Subject: Re: FW: Kolb-List: FireStar 2 Kit Received !
John
The way the sun hits her she looks like she is smiling.
Rick
On Wed, Mar 16, 2016 at 4:05 PM, John Hauck
wrote:
Homer Kolb designed his wing for a reason. It works.
I have never, in 32 years changed the outside dimensions of an
Ultrastar, Firestar, or MKIII wing. They work for me.
Plastic wheels don't even make good paper weights.
A varmint decided to taste the fabric on the right main gear of my
MKIII. We just completely rebuilt, fabric and paint, both main gear a
year ago. I'd shoot him is I could find him. Have no idea what it was.
I was over at Gantt International Airport yesterday taking photos of
the damage. Took a couple extra of the environment over there. My
little piece of heaven.
Spring has sprung at hauck's holler. The weeds have sprouted. One can
watch them grow they are so fast. Spring is my favorite season.
Everything is already covered with pollen. ;-)
john h
mkIII
Titus, Alabama
-----Original Message-----
From: owner-kolb-list-server(at)matronics.com
[mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Bill Berle
Sent: Wednesday, March 16, 2016 12:33 PM
Subject: Re: Kolb-List: FireStar 2 Kit Received !
Well, the used FS2 kit that I had purchased has arrived! I picked it up
form the Yellow Freight terminal (YRC nowdays) last night. Got it back
to my hangar, and was able to spend a couple of hours unpacking most of
it. I have not been able to do a full inventory, because I do not have a
full inventory sheet from Kolb. But I have a lot of various airplane
hardware floating around in my hangar :)
One of the chimpanzees involved somewhere in the shipping crushed two or
three small tubes in the horizontal stabilizers.
The fuselage cage had been hand-painted with white brush-on house paint
or something. I'm thankful for that, because there is only minor
corrosion in the form of brown stains in the white paint, and no serious
pitting. I will eventually have it blasted and re-primed or powder
coated. Any suggestions, warnings, or experience good or bad with powder
coating and steel priming is welcome.
The kit came with brownish-red plastic wheels and 15 x 6.00 x 6 tires.
Alumuinum gear legs, short windshield, one gas can. It is serial number
FS-636, the instruction manual is dated 1996.
The aluminum tube for the tailboom ("fuselage tube" in Kolb language)
had apparently been accidentally drilled for the wing ribs, because the
original builder did not realize the tubes were different. So I may be
able to salvage it, repair it, or plug the holes with "Dead" rivets. Or,
I may have to replace the tube.
I will be using 4 stroke power on this, as I have mentioned previously.
Dagwodzz has been very kind to spend some quality time with me on the
phone educating me about V-twins. Thank you Dagz! I am also looking at
the absolutely beautiful Pegasus Power O-100 engine from Pete Plumb in
California. I have seen this engine run in person and was very very
impressed.
If anyone can point me to specific articles or archives on this list
regarding technical errors in the plans or instructions, or common
problems building the FireStar, Again I am happy to hear about it.
I have several minor and medium size modifications and tweaks that I am
looking into on this airplane. Some of them are aerodynamic (raked tips,
VG's, etc.), some of them are engine related (4 stroke), and some of
them are mechanical (aircraft quality hardware and fasteners wherever
possible... I have this stuff laying around).
Glad to be a brand new, green, wet-behind-the-ears Kolber !
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and
for-profit entities
--------------------------------------------
On Tue, 3/15/16, Richard Girard wrote:
Subject: Re: Kolb-List: Re: Tires for your Firestar
To: "kolb-list(at)matronics.com"
Date: Tuesday, March 15, 2016, 9:21 AM
you could also try
this. I've never used it, can't make a
recommendation.
https://www.zoro.com/3m-flexible-foam-nvh-08463/i/G0406463/?gdffi=047ad
a998cf641fa93e55ae8579df863
&gdfms=5EA4232146CF4B229C255AAAF651CF33&gclid=CPW8-dyLw8sCFQYIaQodCZw
Ijw&gclsrc=aw.ds
Lots of Youtube videos about using urethane foam to fill tires, too,
but it doesn't remain flexible so it'll crush up over time and make a
mess in something like an aircraft tire.
Rick
On Mon, Mar 14, 2016
at 1:08 PM, Bill Berle
wrote:
Bill Berle
Here's a potential game-changer solution right here...
http://www.goldspeedproducts.com/shop/tire-blocks/
These are foam inserts that allow you to run lower pressure and even
run safely when punctured flat.
I'll bet that these foam blocks weigh less than the three piece tire
iron set that was mentioned earlier, or the can of flat tire repair
goop :)
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and for-profit entities
--------------------------------------------
On Mon, 3/14/16, Larry Cottrell
wrote:
Subject: Re: Kolb-List: Re: Tires for your Firestar
To: "kolb-list(at)matronics.com"
Date: Monday, March 14, 2016, 10:37 AM
"
I
will have a small lightweight tool kit with me, and a tire
pump. Even on a certified172 I can take the wheel off the
airplane with a medium Crescent wrench, take the wheel apart
with three 1/4 inch bolts, replace an inner tube or patch a
tire, and get it back together to fly back
home."
I just
carry a can of "spare tire" wrapped in bubble wrap
in the back of my plane.
Larry
On Mon, Mar 14, 2016
at 10:56 AM, Bill Berle
wrote:
Bill Berle
Yes, I want to make it clear that I'm not trying to
hassle or trash-talk anyone or their product. I do prefer
not having to wrestle with someone just to get an answer to
my question, but regardless of the effort it takes to get
that answer my motives and agendas are positive and not
negative.
My situation is that I want to fly extreme-STOL up in the
mountains and desert. I've been scouting several
locations in my 172, and believe it or not most of them are
actually within 50 or 60 miles of the "big city"
limits. So it's not like I'm going out Grizzly bear
bow hunting in the Aleutian Islands or anything... but
it's still way too far for me to just "walk into
town" with a tire and wheel in my hands.
I will have a small lightweight tool kit with me, and a tire
pump. Even on a certified172 I can take the wheel off the
airplane with a medium Crescent wrench, take the wheel apart
with three 1/4 inch bolts, replace an inner tube or patch a
tire, and get it back together to fly back home.
Bill Berle
--------------------------------------------
On Mon, 3/14/16, Richard Girard
wrote:
Subject: Re: Kolb-List: Re: Tires for your Firestar
To: "kolb-list(at)matronics.com"
Date: Monday, March 14, 2016, 9:29 AM
I have three metal
tire irons that I carry with me. Less than 1 lb. for the
set
and with a little water as lubricant they get the tire off
a
one piece wheel just fine. It's breaking the bead
that's the trick and for that I just use a hammer
with
one iron to get it started. It's not what I'd use
at
home, but we're talking stranded in the outback with
the
vultures circling. :-}
Rick Girard
On Mon, Mar 14, 2016
at 9:16 AM, Charlie England
wrote:
Charlie England
The tires and wheels do look nice, and are likely a good
option if flying close to home.
However, it seems like you're missing his point.
He's talking about real 'bush' flying, away
from
airports & service facilities. With conventional 2
piece
wheels, you could break them down with simple hand tools
to
repair a flat, and a small hand pump to re-inflate. But
with
auto-style one piece wheels, it requires specialized
(heavy)
tools to break a tire down for repair. Not likely to be in
a
tool kit you can carry in a Kolb or other very light
a/c.
Charlie
On 3/13/2016 11:19 PM, Carolina Flyer wrote:
Flyer"
Bill, I use a cheap harbor freight device for putting
the
tires on, cost $49.95 I think.
Rick, The only tires that I sell are these that I have
pictures of and they fit on a 8 inch rims
--------
Kolb Firestar II
503 C-Box / RK400
Soon to have a
Rotax 670 DCDI
with a C-Box and
RK 400 Clutch
Challenger II
503 Tall Drive
Location : Buffalo South Carolina
==========
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Marx
________________________________________________________________________________
| From: | "John Hauck" <jhauck(at)elmore.rr.com> |
Looks good, and I bet they do work much better.
john h
mkIII
Titus, Alabama
-----Original Message-----
From: owner-kolb-list-server(at)matronics.com
[mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Rex Rodebush
Sent: Wednesday, March 16, 2016 4:17 PM
Subject: Kolb-List: Re: Kolb tires
Attached are pictures of the brake pedals I modified to fit my feet.
I bought new Matco wheels about 2 years ago as they are thicker and Matco
had cracking problems with the old ones. I ordered the new machined caliper
with the wheels as they have a larger piston than the old cast versions.
The braking was better but still not acceptable. I then mounted the old
calipers on in addition as the wheels were drilled for dual calipers and the
mounting holes were the same.
Now the braking is great.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=453823#453823
Attachments:
http://forums.matronics.com//files/brakes2_167.jpg
http://forums.matronics.com//files/brakes1_204.jpg
________________________________________________________________________________
| Subject: | Re: FireStar 2 Kit Received ! |
| From: | Charlie England <ceengland7(at)gmail.com> |
I assume that Rick is talking about the Pegasus. I'd bet it uses the
standard Cont. conical mount, but it's still on the back of the engine
instead of the bottom. But more important (at least to me), be sure to
truly count the cost. In the early versions I saw, the actual cost to
get one running was 2 or 3 times the kit cost. Note that there are no
cylinders mentioned on the list of what's included. Assuming that you
must buy your own cylinders, ask him how he can safely run 9-1
compression with the stock Cont. cyl heads & mogas. (Original engine had
7.0-1 compression.) Also, ask what the *real* horsepower is. Most Cont
guys say that the original O-200 4 cyl was only good for maybe 85-90 hp
on its best day, and with a fixed pitch prop, you won't come anywhere
near rated power on takeoff, when you need it. Half of 90 is only 45 HP.
On a tractor a/c, a big Vtwin with reduction swinging a large diameter
prop just might outclimb the O-100, even carrying an extra 15-20 lbs of
weight.
There are other (a lot more work required) options, like
https://www.youtube.com/watch?v=1_Tlg9RMKx8
(I think the builder has been on the is list in the past)
or
http://www.rotaryforum.com/forum/showthread.php?t=16100&highlight=yamaha
Charlie
On 3/16/2016 2:49 PM, Rick Neilsen wrote:
> Bill
>
> Consider that new engine very carefully. I'm speaking from experience.
> I was the first to put a VW on a Kolb. It is a big undertaking. First
> the Pegasus Power O-100 engine uses a difocal mount and kolbs have a
> bed type mount. I had to fabricate a custom mount for the VW. I had
> help as GP Aircraft made a prop end mount that made it easier. You
> will have to fabricate a custom exhaust system. You will need to enter
> the black science of prop selection. You may like magnetos but I
> don't, they are heavy, expensive, under powered, and there is a reason
> they come in pairs. Now the real tough stuff, the engine is still in
> development. You will be the test pilot for not just the engine
> installation but for the engine too.
>
> Don't get me wrong I'm not trying to talk you out of it but do not
> underestimate the task you will be taking on. I spent one extra year
> installing my VW. Then I changed to a redrive VW engine. Then I had a
> redrive failure. Then I fabricated a new lower engine mount. Five
> years later I was still tweaking exhaust systems, Props, carb
> settings, and redrive ratios. Eighteen years later I'm
> still battling engine noise - the engine mount transmits too much
> vibration noise to the airframe. One of my high engine mounts had a
> soft enough mount that was very smooth and quiet but chewed up engine
> mounting bushings/dampers.
>
> One more thing, engine builders overestimate power and underestimate
> weight and price.
>
> It could be a worthy challenge but are you up to it?
>
> Rick Neilsen
> Redrive VW Powered MKIIIC
>
> On Wed, Mar 16, 2016 at 1:33 PM, Bill Berle > wrote:
>
> >
>
> Well, the used FS2 kit that I had purchased has arrived! I picked
> it up form the Yellow Freight terminal (YRC nowdays) last night.
> Got it back to my hangar, and was able to spend a couple of hours
> unpacking most of it. I have not been able to do a full inventory,
> because I do not have a full inventory sheet from Kolb. But I have
> a lot of various airplane hardware floating around in my hangar :)
>
> One of the chimpanzees involved somewhere in the shipping crushed
> two or three small tubes in the horizontal stabilizers.
>
> The fuselage cage had been hand-painted with white brush-on house
> paint or something. I'm thankful for that, because there is only
> minor corrosion in the form of brown stains in the white paint,
> and no serious pitting. I will eventually have it blasted and
> re-primed or powder coated. Any suggestions, warnings, or
> experience good or bad with powder coating and steel priming is
> welcome.
>
> The kit came with brownish-red plastic wheels and 15 x 6.00 x 6
> tires. Alumuinum gear legs, short windshield, one gas can. It is
> serial number FS-636, the instruction manual is dated 1996.
>
> The aluminum tube for the tailboom ("fuselage tube" in Kolb
> language) had apparently been accidentally drilled for the wing
> ribs, because the original builder did not realize the tubes were
> different. So I may be able to salvage it, repair it, or plug the
> holes with "Dead" rivets. Or, I may have to replace the tube.
>
> I will be using 4 stroke power on this, as I have mentioned
> previously. Dagwodzz has been very kind to spend some quality time
> with me on the phone educating me about V-twins. Thank you Dagz! I
> am also looking at the absolutely beautiful Pegasus Power O-100
> engine from Pete Plumb in California. I have seen this engine run
> in person and was very very impressed.
>
> If anyone can point me to specific articles or archives on this
> list regarding technical errors in the plans or instructions, or
> common problems building the FireStar, Again I am happy to hear
> about it.
>
> I have several minor and medium size modifications and tweaks that
> I am looking into on this airplane. Some of them are aerodynamic
> (raked tips, VG's, etc.), some of them are engine related (4
> stroke), and some of them are mechanical (aircraft quality
> hardware and fasteners wherever possible... I have this stuff
> laying around).
>
> Glad to be a brand new, green, wet-behind-the-ears Kolber !
>
>
> Bill Berle
> www.ezflaphandle.com <http://www.ezflaphandle.com> - safety &
> performance upgrade for light aircraft
> www.grantstar.net <http://www.grantstar.net> - winning
> proposals for non-profit and for-profit entities
>
> --------------------------------------------
> On Tue, 3/15/16, Richard Girard > wrote:
>
> Subject: Re: Kolb-List: Re: Tires for your Firestar
> To: "kolb-list(at)matronics.com "
> >
> Date: Tuesday, March 15, 2016, 9:21 AM
>
> you could also try
> this. I've never used it, can't make a
> recommendation.
> https://www.zoro.com/3m-flexible-foam-nvh-08463/i/G0406463/?gdffi=047ada998cf641fa93e55ae8579df863&gdfms=5EA4232146CF4B229C255AAAF651CF33&gclid=CPW8-dyLw8sCFQYIaQodCZwIjw&gclsrc=aw.ds
>
> Lots of Youtube videos about using urethane foam
> to fill tires, too, but it doesn't remain flexible so
> it'll crush up over time and make a mess in something
> like an aircraft tire.
> Rick
> On Mon, Mar 14, 2016
> at 1:08 PM, Bill Berle >
> wrote:
> Bill Berle >
>
>
> Here's a potential game-changer solution right
> here...
>
>
> http://www.goldspeedproducts.com/shop/tire-blocks/
>
>
> These are foam inserts that allow you to run lower pressure
> and even run safely when punctured flat.
>
>
> I'll bet that these foam blocks weigh less than the
> three piece tire iron set that was mentioned earlier, or the
> can of flat tire repair goop :)
>
>
> Bill Berle
>
> www.ezflaphandle.com <http://www.ezflaphandle.com>
> - safety & performance upgrade for light aircraft
>
> www.grantstar.net <http://www.grantstar.net>
> - winning proposals for non-profit and for-profit
> entities
>
>
________________________________________________________________________________
| Subject: | FireStar 2 Kit Received ! |
| From: | B Young <byoungplumbing(at)gmail.com> |
Aw shucks. Not all that greedy.., Even if it burnt 2 GPH!!!! I'm all
in... He said with a big grin on his face;-) ;-) ;-) ;-)
Boyd. Lol
Xxxxxxxxxxxxx
that is safe, reliable, more power than ever needed, cheap, and burns 1 GPH.
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | Re: FireStar 2 Kit Received ! |
The prototype Pegasus does use the stock Continental conical mounts on the back
of the case. There may be another upcoming mounting system for it that might
be better suited to the Kolb, but that is for Pete to discuss and not me.
The O-200 makes horsepower in proportion to the RPM, I have flown the O-200 from
2000 RPM to 4300 RPM (Reno F-1 race). The power curve drops off dramatically
above 3200, and reliability goes way down. A properly balanced and lubricated
O-200 (or O-100) will maintain very good reliability at 3000 RPM. Better than
a stock un-balanced
I am not an engine expert, but I do know that actual real-world reliability over
the last 60+ years of airplane engines strongly favors the 4 stroke engines.
When Rotax finally decided to create an engine specifically for airplanes, they
chose a 4 stroke despite the fact that by then they were the absolute world
leader in 2 stroke engines in experimental aircraft. There has to be a reason
for that, and it's not just EPA pollution regulations.
I assume that
Rick is talking about the
Pegasus. I'd bet it uses the standard Cont.
conical mount, but
it's still on the back of the engine instead of
the bottom. But
more important (at least to me), be sure to truly
count the cost.
In the early versions I saw, the actual cost to get
one running
was 2 or 3 times the kit cost. Note that there are no
cylinders
mentioned on the list of what's included. Assuming
that you must
buy your own cylinders, ask him how he can safely run
9-1
compression with the stock Cont. cyl heads &
mogas. (Original
engine had 7.0-1 compression.) Also, ask what the
*real*
horsepower is. Most Cont guys say that the original
O-200 4 cyl
was only good for maybe 85-90 hp on its best day, and
with a fixed
pitch prop, you won't come anywhere near rated
power on takeoff,
when you need it. Half of 90 is only 45 HP. On a
tractor a/c, a
big Vtwin with reduction swinging a large diameter
prop just might
outclimb the O-100, even carrying an extra 15-20 lbs
of weight.
There are other (a lot more work required) options,
like
https://www.youtube.com/watch?v=1_Tlg9RMKx8
(I think the builder has been on the is list in the
past)
or
http://www.rotaryforum.com/forum/showthread.php?t=16100&highlight=yamaha
Charlie
On 3/16/2016 2:49 PM, Rick Neilsen wrote:
Bill
Consider that new
engine very carefully. I'm speaking from
experience. I was
the first to put a VW on a Kolb. It is a big
undertaking.
First thePegasus Power
O-100 engine
uses a difocalmount and kolbs have a bed type
mount. I had
tofabricatea custom mount for the VW. I had
help as GP
Aircraft made a prop end mount that made
iteasier. You will
have to fabricate a custom exhaustsystem. You
will need to
enter the black science of prop selection. You
may
likemagnetos but I don't, they are heavy,
expensive, under
powered, and there is a reason they come in
pairs.Now the
real tough stuff, the engine is still in
development. You
will be the test pilot for not just the engine
installation
but for the engine too.
Don't get me wrong I'm
not trying to talk you out of it but do not
underestimate
the task you will be taking on. I spent one
extra year
installing my VW. Then Ichangedto a
redriveVW engine.
Then I had a redrive failure. Then
Ifabricateda new lower
engine mount. Five years later I was
stilltweakingexhaustsystems, Props, carb
settings, and
redrive ratios. Eighteen years later I'm
stillbattlingengine noise - the engine
mounttransmitstoo
much vibration noise to the airframe. One of my
high engine
mounts had a soft enough mount that was very
smooth and
quiet but chewed up engine mounting
bushings/dampers.
One more thing, engine
buildersoverestimatepower and underestimate
weight and
price.
It could be a
worthychallenge but are you up to
it?
Rick Neilsen
Redrive VW Powered
MKIIIC
On Wed, Mar
16, 2016 at 1:33 PM, Bill
Berle
wrote:
-->
Kolb-List message posted by: Bill Berle
Well, the used FS2 kit that I had purchased has
arrived! I
picked it up form the Yellow Freight terminal
(YRC nowdays)
last night. Got it back to my hangar, and was
able to spend
a couple of hours unpacking most of it. I have
not been able
to do a full inventory, because I do not have a
full
inventory sheet from Kolb. But I have a lot of
various
airplane hardware floating around in my hangar
:)
One of the chimpanzees involved somewhere in the
shipping
crushed two or three small tubes in the
horizontal
stabilizers.
The fuselage cage had been hand-painted with
white brush-on
house paint or something. I'm thankful for
that, because
there is only minor corrosion in the form of
brown stains in
the white paint, and no serious pitting. I will
eventually
have it blasted and re-primed or powder coated.
Any
suggestions, warnings, or experience good or bad
with powder
coating and steel priming is welcome.
The kit came with brownish-red plastic wheels
and 15 x 6.00
x 6 tires. Alumuinum gear legs, short
windshield, one gas
can. It is serial number FS-636, the instruction
manual is
dated 1996.
The aluminum tube for the tailboom
("fuselage tube" in Kolb
language) had apparently been accidentally
drilled for the
wing ribs, because the original builder did not
realize the
tubes were different. So I may be able to
salvage it, repair
it, or plug the holes with "Dead"
rivets. Or, I may have to
replace the tube.
I will be using 4 stroke power on this, as I
have mentioned
previously. Dagwodzz has been very kind to spend
some
quality time with me on the phone educating me
about
V-twins. Thank you Dagz! I am also looking at
the absolutely
beautiful Pegasus Power O-100 engine from Pete
Plumb in
California. I have seen this engine run in
person and was
very very impressed.
If anyone can point me to specific articles or
archives on
this list regarding technical errors in the
plans or
instructions, or common problems building the
FireStar,
Again I am happy to hear about it.
I have several minor and medium size
modifications and
tweaks that I am looking into on this airplane.
Some of them
are aerodynamic (raked tips, VG's, etc.),
some of them are
engine related (4 stroke), and some of them are
mechanical
(aircraft quality hardware and fasteners
wherever
possible... I have this stuff laying around).
Glad to be a brand new, green,
wet-behind-the-ears Kolber !
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light
aircraft
www.grantstar.net
- winning proposals for non-profit and
for-profit
entities
--------------------------------------------
On Tue, 3/15/16, Richard Girard
wrote:
Subject: Re: Kolb-List: Re: Tires for your
Firestar
To: "kolb-list(at)matronics.com"
Date: Tuesday, March 15, 2016, 9:21 AM
you could also try
this. I've never used it, can't make
a
recommendation.
https://www.zoro.com/3m-flexible-foam-nvh-08463/i/G0406463/?gdffi=047ada998cf641fa93e55ae8579df863&gdfms=5EA4232146CF4B229C255AAAF651CF33&gclid=CPW8-dyLw8sCFQYIaQodCZwIjw&gclsrc=aw.ds
Lots of Youtube videos about using urethane
foam
to fill tires, too, but it doesn't remain
flexible so
it'll crush up over time and make a mess
in something
like an aircraft tire.
Rick
On Mon, Mar 14, 2016
at 1:08 PM, Bill Berle
wrote:
Bill Berle
Here's a potential game-changer solution
right
here...
http://www.goldspeedproducts.com/shop/tire-blocks/
These are foam inserts that allow you to run
lower pressure
and even run safely when punctured flat.
I'll bet that these foam blocks weigh less
than the
three piece tire iron set that was mentioned
earlier, or
the
can of flat tire repair goop :)
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light
aircraft
www.grantstar.net
- winning proposals for non-profit
and for-profit
entities
________________________________________________________________________________
| Subject: | Re: FireStar 2 Kit Received ! |
| From: | Charlie England <ceengland7(at)gmail.com> |
No argument from me on the 4 stroke issue; both links are to 4 stroke
engines. If you try to run the Pegasus direct drive at >3k rpm, you're
going to hit the same wall that Rick did with his VW; inadequate mass
flow through the required small diameter prop at the relatively low
speeds of a Kolb. If you run it at Continental-like rpms with an
adequate diameter prop, I'd bet you'll do good to get 40 hp.
Charlie
On 3/16/2016 6:12 PM, Bill Berle wrote:
>
> The prototype Pegasus does use the stock Continental conical mounts on the back
of the case. There may be another upcoming mounting system for it that might
be better suited to the Kolb, but that is for Pete to discuss and not me.
>
> The O-200 makes horsepower in proportion to the RPM, I have flown the O-200 from
2000 RPM to 4300 RPM (Reno F-1 race). The power curve drops off dramatically
above 3200, and reliability goes way down. A properly balanced and lubricated
O-200 (or O-100) will maintain very good reliability at 3000 RPM. Better than
a stock un-balanced
>
> I am not an engine expert, but I do know that actual real-world reliability over
the last 60+ years of airplane engines strongly favors the 4 stroke engines.
When Rotax finally decided to create an engine specifically for airplanes,
they chose a 4 stroke despite the fact that by then they were the absolute world
leader in 2 stroke engines in experimental aircraft. There has to be a reason
for that, and it's not just EPA pollution regulations.
>
>
> I assume that
> Rick is talking about the
> Pegasus. I'd bet it uses the standard Cont.
> conical mount, but
> it's still on the back of the engine instead of
> the bottom. But
> more important (at least to me), be sure to truly
> count the cost.
> In the early versions I saw, the actual cost to get
> one running
> was 2 or 3 times the kit cost. Note that there are no
> cylinders
> mentioned on the list of what's included. Assuming
> that you must
> buy your own cylinders, ask him how he can safely run
> 9-1
> compression with the stock Cont. cyl heads &
> mogas. (Original
> engine had 7.0-1 compression.) Also, ask what the
> *real*
> horsepower is. Most Cont guys say that the original
> O-200 4 cyl
> was only good for maybe 85-90 hp on its best day, and
> with a fixed
> pitch prop, you won't come anywhere near rated
> power on takeoff,
> when you need it. Half of 90 is only 45 HP. On a
> tractor a/c, a
> big Vtwin with reduction swinging a large diameter
> prop just might
> outclimb the O-100, even carrying an extra 15-20 lbs
> of weight.
>
>
>
> There are other (a lot more work required) options,
> like
>
> https://www.youtube.com/watch?v=1_Tlg9RMKx8
>
> (I think the builder has been on the is list in the
> past)
>
> or
>
> http://www.rotaryforum.com/forum/showthread.php?t=16100&highlight=yamaha
>
>
>
> Charlie
>
>
>
> On 3/16/2016 2:49 PM, Rick Neilsen wrote:
>
>
>
>
> Bill
>
>
>
> Consider that new
> engine very carefully. I'm speaking from
> experience. I was
> the first to put a VW on a Kolb. It is a big
> undertaking.
> First the Pegasus Power
> O-100 engine
> uses a difocal mount and kolbs have a bed type
> mount. I had
> to fabricate a custom mount for the VW. I had
> help as GP
> Aircraft made a prop end mount that made
> it easier. You will
> have to fabricate a custom exhaust system. You
> will need to
> enter the black science of prop selection. You
> may
> like magnetos but I don't, they are heavy,
> expensive, under
> powered, and there is a reason they come in
> pairs. Now the
> real tough stuff, the engine is still in
> development. You
> will be the test pilot for not just the engine
> installation
> but for the engine too.
>
>
>
> Don't get me wrong I'm
> not trying to talk you out of it but do not
> underestimate
> the task you will be taking on. I spent one
> extra year
> installing my VW. Then I changed to a
> redrive VW engine.
> Then I had a redrive failure. Then
> I fabricated a new lower
> engine mount. Five years later I was
> still tweaking exhaust systems, Props, carb
> settings, and
> redrive ratios. Eighteen years later I'm
> still battling engine noise - the engine
> mount transmits too
> much vibration noise to the airframe. One of my
> high engine
> mounts had a soft enough mount that was very
> smooth and
> quiet but chewed up engine mounting
> bushings/dampers.
>
>
>
> One more thing, engine
> builders overestimate power and underestimate
> weight and
> price.
>
>
>
> It could be a
> worthy challenge but are you up to
> it?
>
>
>
> Rick Neilsen
> Redrive VW Powered
> MKIIIC
>
>
>
> On Wed, Mar
> 16, 2016 at 1:33 PM, Bill
> Berle
> wrote:
>
> -->
> Kolb-List message posted by: Bill Berle
>
>
>
> Well, the used FS2 kit that I had purchased has
> arrived! I
> picked it up form the Yellow Freight terminal
> (YRC nowdays)
> last night. Got it back to my hangar, and was
> able to spend
> a couple of hours unpacking most of it. I have
> not been able
> to do a full inventory, because I do not have a
> full
> inventory sheet from Kolb. But I have a lot of
> various
> airplane hardware floating around in my hangar
> :)
>
>
>
> One of the chimpanzees involved somewhere in the
> shipping
> crushed two or three small tubes in the
> horizontal
> stabilizers.
>
>
>
> The fuselage cage had been hand-painted with
> white brush-on
> house paint or something. I'm thankful for
> that, because
> there is only minor corrosion in the form of
> brown stains in
> the white paint, and no serious pitting. I will
> eventually
> have it blasted and re-primed or powder coated.
> Any
> suggestions, warnings, or experience good or bad
> with powder
> coating and steel priming is welcome.
>
>
>
> The kit came with brownish-red plastic wheels
> and 15 x 6.00
> x 6 tires. Alumuinum gear legs, short
> windshield, one gas
> can. It is serial number FS-636, the instruction
> manual is
> dated 1996.
>
>
>
> The aluminum tube for the tailboom
> ("fuselage tube" in Kolb
> language) had apparently been accidentally
> drilled for the
> wing ribs, because the original builder did not
> realize the
> tubes were different. So I may be able to
> salvage it, repair
> it, or plug the holes with "Dead"
> rivets. Or, I may have to
> replace the tube.
>
>
>
> I will be using 4 stroke power on this, as I
> have mentioned
> previously. Dagwodzz has been very kind to spend
> some
> quality time with me on the phone educating me
> about
> V-twins. Thank you Dagz! I am also looking at
> the absolutely
> beautiful Pegasus Power O-100 engine from Pete
> Plumb in
> California. I have seen this engine run in
> person and was
> very very impressed.
>
>
>
> If anyone can point me to specific articles or
> archives on
> this list regarding technical errors in the
> plans or
> instructions, or common problems building the
> FireStar,
> Again I am happy to hear about it.
>
>
>
> I have several minor and medium size
> modifications and
> tweaks that I am looking into on this airplane.
> Some of them
> are aerodynamic (raked tips, VG's, etc.),
> some of them are
> engine related (4 stroke), and some of them are
> mechanical
> (aircraft quality hardware and fasteners
> wherever
> possible... I have this stuff laying around).
>
>
>
> Glad to be a brand new, green,
> wet-behind-the-ears Kolber !
>
>
>
>
>
> Bill Berle
>
________________________________________________________________________________
| Subject: | Re: New (free) Aviation App |
| From: | "gbrasch" <gmbrasch(at)gmail.com> |
We just completed a major upgrade to Airport Courtesy Cars App, which now makes the app available on ALL devices, including the web. Please upgrade your app to the latest version. If your phone does not support the app, then go to our new website, www.airportcourtesycars.com The site is mobile friendly and you can place its icon to your phone or tablet screen. Both versions show Google maps for each state, the app version still shows the entire US map which some people prefer. The site currently lists over 1560 cars. Thanks for your input and contact us with any questions, new listings, or corrections to airportcars101(at)gmail.com And please check out our advertisers and FBOs who offer you fuel discounts. The app remains free.
--------
Glenn Brasch
RV-9A Flying
Medevac Helicopter Pilot (Ret)
Owner, "Airport Courtesy Cars" Smart Phone App
and www.airportcourtesycars.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=453848#453848
________________________________________________________________________________
| Subject: | Re: Fixing a Flat Tire |
| From: | Brad Nation <nationcap(at)comcast.net> |
I have used Fix-A-Flat on other flats and one of the things I learned is that you
need to spin the tire as soon after using it so that the fix-it is spread out
evenly over the outer side of the inside of the tire.
Brad Nation
MK3 Xtra
________________________________________________________________________________
| From: | "John Hauck" <jhauck(at)elmore.rr.com> |
| Subject: | FireStar 2 Kit Received ! |
Hi Folks:
The paragraphs in quotation marks are Bill B's.
Homer Kolb didn't design the Kolbra. That aircraft was designed and built some
time after the original Kolb Aircraft Co was sold.
"Mr. Kolb himself changed the wing dimensions to create the Slingshot, Kolbra,
Firelfy, and others. He also changed the angle of incidence (wing mounting angle)
to create different characteristics on different models."
All Kolb wing dimensions are the same, except length of the wing panel. Shape
of the rib and cord is the same on all models.
The Slingshot had less incidence because of the high main gear and the nose high
attitude the aircraft sat on the ground. It also flew faster, pulling the tail
boom parallel through the air stream. At slower speeds the SS really drags
its tail. Very tail low. Other Kolb models fly tail high because of the excessive
incidence.
"Raked wingtips are shown to work, especially at high AoA and low speeds. They
create a pressure field that slightly reduces the wingtip vortex."
I think you will find that Homer's wingtip takes care of the above.
"VG's are shown to work great, especially on simple turbulent flow airfoils like
the Cub, Kolb, and Aeronca. They help the airflow stay attached to the wing
at higher AoA. This results in better control authority at low speeds, which will
be a lifesaver in off-airport STOL operations."
All Kolb models have excellent low speed flight characteristics without VGs. About
the only thing I have been able to determine with the addition of VGs on
a Kolb is more gentle break on landing, and slightly less stall speed.
"Mr. Kolb designed the landing gear to be as easy and low-risk for new or low-time
pilots as possible. It worked, and the Kolb has a wonderful reputation for
easy ground handling. This is just what the doctor ordered for a kit plane that
was safe for low time pilots. But this mellow ground handling comes at the
cost of losing the ideal ground angle for the wing to take off and land slower.
A longer or taller landing gear requires a slightly more experienced pilot,
but you get better STOL performance in the bargain."
The Hauck Brothers have been designing and building "tall" landing gear for Kolb
aircraft for 30 years. We put the first pair of heat treated 4130 legs on a
Kolb. The main reason we started experimenting with long legs on my FS was the
lack of brakes. One of the first mods to my FS was 4130 streamlined lift struts.
They cleaned up the FS so much I couldn't get it stopped on my short grass
strip. The 36" legs turned the bottom of the wing up more and helped slow
the FS down on landing. They also made nice springs, and worked wonders for
softening up the suspension.
BTW Bill B, tell us about your Kolb experience, please.
john h
mkIII
Titus, Alabama
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | FireStar 2 Kit Received ! |
I have no Kolb experience whatsoever. This is my first Kolb. So some of my ideas
may not work out as well as I hope, and some of them may work better than I
imagined. The challenge and enjoyment of improving the performance of an already
good airplane is one of the things I'm looking forward to.
I have a specific question which you might be able to answer: If you put the wing
on a FireStar at the lower incidence angle of the Slingshot, and then put on
the taller gear from the Slingshot, would you get both benefits (a higher cruise
speed from the tailboom flying straight), AND better STOL performance (from
the higher ground angle)?
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Wed, 3/16/16, John Hauck wrote:
Subject: RE: FW: Kolb-List: FireStar 2 Kit Received !
To: kolb-list(at)matronics.com
Date: Wednesday, March 16, 2016, 8:03 PM
"John Hauck"
Hi Folks:
The paragraphs in quotation marks are Bill B's.
Homer Kolb didn't design the Kolbra. That aircraft was
designed and built some time after the original Kolb
Aircraft Co was sold.
"Mr. Kolb himself changed the wing dimensions to create the
Slingshot, Kolbra, Firelfy, and others. He also changed the
angle of incidence (wing mounting angle) to create different
characteristics on different models."
All Kolb wing dimensions are the same, except length of the
wing panel. Shape of the rib and cord is the same on
all models.
The Slingshot had less incidence because of the high main
gear and the nose high attitude the aircraft sat on the
ground. It also flew faster, pulling the tail boom
parallel through the air stream. At slower speeds the
SS really drags its tail. Very tail
low.Other Kolb models fly tail high
because of the excessive incidence.
"Raked wingtips are shown to work, especially at high AoA
and low speeds. They create a pressure field that slightly
reduces the wingtip vortex."
I think you will find that Homer's wingtip takes care of the
above.
"VG's are shown to work great, especially on simple
turbulent flow airfoils like the Cub, Kolb, and Aeronca.
They help the airflow stay attached to the wing at higher
AoA. This results in better control authority at low speeds,
which will be a lifesaver in off-airport STOL operations."
All Kolb models have excellent low speed flight
characteristics without VGs. About the only thing I
have been able to determine with the addition of VGs on a
Kolb is more gentle break on landing, and slightly less
stall speed.
"Mr. Kolb designed the landing gear to be as easy and
low-risk for new or low-time pilots as possible. It worked,
and the Kolb has a wonderful reputation for easy ground
handling. This is just what the doctor ordered for a kit
plane that was safe for low time pilots. But this mellow
ground handling comes at the cost of losing the ideal
ground angle for the wing to take off and land slower. A
longer or taller landing gear requires a slightly more
experienced pilot, but you get better STOL performance in
the bargain."
The Hauck Brothers have been designing and building "tall"
landing gear for Kolb aircraft for 30 years. We put
the first pair of heat treated 4130 legs on a Kolb.
The main reason we started experimenting with long legs on
my FS was the lack of brakes. One of the first mods to
my FS was 4130 streamlined lift struts. They cleaned
up the FS so much I couldn't get it stopped on my short
grass strip. The 36" legs turned the bottom of the
wing up more and helped slow the FS down on landing.
They also made nice springs, and worked wonders for
softening up the suspension.
BTW Bill B, tell us about your Kolb experience, please.
john h
mkIII
Titus, Alabama
Lists This Month --
Some AWESOME FREE Gifts!)
Raiser. Click on
more about
Gifts provided
www.buildersbooks.com
-Matt
Dralle, List Admin.
Forum -
- MATRONICS WEB FORUMS -
List Contribution Web Site -
-Matt
Dralle, List Admin.
________________________________________________________________________________
| From: | "John Hauck" <jhauck(at)elmore.rr.com> |
| Subject: | FireStar 2 Kit Received ! |
I always thought dragging the tail boom straight, instead of sideways
through the air, would clean it up a bit and increase cruise. The SS
and Kolbra utilize that design technique with lower incidence to
increase cruise. John Williamson's Kolbra, with 912ULS, same engine on
my MKIII, cruised 10 mph faster at the same rpm. Top speed is about 10
to 15 mph quicker. The major difference in drag between the Kolbra/SS
and the MKIII was the difference between the width and shape of the
fuselage. Also, the Kolbra had less wing area because it did not have
flaps. The MKIII flies slower and gets off the ground quicker.
Actually, the fuselage of the FS would have to be redesigned because the
tail boom was designed to fly tail high. Flying with the tail boom
horizontal would make the pilot feel as though he were laying on his
back and climbing all the time.
My original Firestar was faster and flew slower than the FSII. It had
full span ailerons. The FSII is like the Kolbra with half span.
I am a firm believer is extremely tight fabric. I believe this is one
of the major differences between air speed/flight characteristic
differences of the same model Kolbs. My MKIII has never been outrun by
another MKIII. Same for my original FS. Both aircraft had fabric that
bowed the tubes on wings and empennage. Soft fabric changes shape much
more than tight fabric.
There were a lot of things I would have liked to experiment with my
Kolbs over the last 32 years, but age caught up with me before I got
them all done. Then I got to the stage that what I have now is great.
It does what I need. It is an 85 mph cruise aircraft. If I can find a
15 mph tailwind, then I've got a temporary 100 mph airplane across the
ground. It will carry everything I can cram into it to keep me and it
going for extended periods of time. So far, the longest duration flight
was 48 days. The longest flight was 17,400 sm in 41 days and 232.0
flight hours. It will keep me in the air for 5 hours, if I could do
that without wetting my pants. It gets me in and out of tiny fields,
two track trails, gravel bars, beaches on the Atlantic, the Gulf of
Mexico, the Arctic Ocean, and small dry lakes in the dessert. It does
much more than Homer Kolb and John Hauck ever dreamed one of his little
airplanes would do. It takes me where I want to go. All I have to do
is put gas in it, take off and point the nose in that direction.
john h
mkIII
Titus, Alabama
-----Original Message-----
From: owner-kolb-list-server(at)matronics.com
[mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Bill Berle
Sent: Thursday, March 17, 2016 3:01 AM
Subject: RE: FW: Kolb-List: FireStar 2 Kit Received !
I have no Kolb experience whatsoever. This is my first Kolb. So some of
my ideas may not work out as well as I hope, and some of them may work
better than I imagined. The challenge and enjoyment of improving the
performance of an already good airplane is one of the things I'm looking
forward to.
I have a specific question which you might be able to answer: If you put
the wing on a FireStar at the lower incidence angle of the Slingshot,
and then put on the taller gear from the Slingshot, would you get both
benefits (a higher cruise speed from the tailboom flying straight), AND
better STOL performance (from the higher ground angle)?
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and
for-profit entities
--------------------------------------------
On Wed, 3/16/16, John Hauck wrote:
Subject: RE: FW: Kolb-List: FireStar 2 Kit Received !
To: kolb-list(at)matronics.com
Date: Wednesday, March 16, 2016, 8:03 PM
"John Hauck"
Hi Folks:
The paragraphs in quotation marks are Bill B's.
Homer Kolb didn't design the Kolbra. That aircraft was designed and
built some time after the original Kolb Aircraft Co was sold.
"Mr. Kolb himself changed the wing dimensions to create the Slingshot,
Kolbra, Firelfy, and others. He also changed the angle of incidence
(wing mounting angle) to create different characteristics on different
models."
All Kolb wing dimensions are the same, except length of the wing
panel. Shape of the rib and cord is the same on all models.
The Slingshot had less incidence because of the high main gear and the
nose high attitude the aircraft sat on the ground. It also flew
faster, pulling the tail boom parallel through the air stream. At
slower speeds the SS really drags its tail. Very tail low. Other
Kolb models fly tail high because of the excessive incidence.
"Raked wingtips are shown to work, especially at high AoA and low
speeds. They create a pressure field that slightly reduces the wingtip
vortex."
I think you will find that Homer's wingtip takes care of the above.
"VG's are shown to work great, especially on simple turbulent flow
airfoils like the Cub, Kolb, and Aeronca.
They help the airflow stay attached to the wing at higher AoA. This
results in better control authority at low speeds, which will be a
lifesaver in off-airport STOL operations."
All Kolb models have excellent low speed flight characteristics
without VGs. About the only thing I have been able to determine with
the addition of VGs on a Kolb is more gentle break on landing, and
slightly less stall speed.
"Mr. Kolb designed the landing gear to be as easy and low-risk for new
or low-time pilots as possible. It worked, and the Kolb has a wonderful
reputation for easy ground handling. This is just what the doctor
ordered for a kit plane that was safe for low time pilots. But this
mellow ground handling comes at the cost of losing the ideal ground
angle for the wing to take off and land slower. A longer or taller
landing gear requires a slightly more experienced pilot, but you get
better STOL performance in the bargain."
The Hauck Brothers have been designing and building "tall"
landing gear for Kolb aircraft for 30 years. We put the first pair of
heat treated 4130 legs on a Kolb. The main reason we started
experimenting with long legs on my FS was the lack of brakes. One of
the first mods to my FS was 4130 streamlined lift struts. They cleaned
up the FS so much I couldn't get it stopped on my short grass strip.
The 36" legs turned the bottom of the wing up more and helped slow the
FS down on landing. They also made nice springs, and worked wonders for
softening up the suspension.
BTW Bill B, tell us about your Kolb experience, please.
john h
mkIII
Titus, Alabama
Lists This Month --
Some AWESOME FREE Gifts!)
Raiser. Click on
more about
Gifts provided
www.buildersbooks.com
-Matt
Dralle, List Admin.
Forum -
- MATRONICS WEB FORUMS -
List Contribution Web Site -
-Matt
Dralle, List Admin.
________________________________________________________________________________
| From: | Dennis Rowe <rowedenny(at)windstream.net> |
| Subject: | Re: FireStar 2 Kit Received ! |
Man, let me know if you ever want to sell Miss Pfer. that was quite the sales
pitch!
Dennis "Skid" Rowe
> On Mar 17, 2016, at 9:22 AM, John Hauck wrote:
>
> I always thought dragging the tail boom straight, instead of sideways through
the air, would clean it up a bit and increase cruise. The SS and Kolbra utilize
that design technique with lower incidence to increase cruise. John Williamson's
Kolbra, with 912ULS, same engine on my MKIII, cruised 10 mph faster at
the same rpm. Top speed is about 10 to 15 mph quicker. The major difference
in drag between the Kolbra/SS and the MKIII was the difference between the width
and shape of the fuselage. Also, the Kolbra had less wing area because it
did not have flaps. The MKIII flies slower and gets off the ground quicker.
>
> Actually, the fuselage of the FS would have to be redesigned because the tail
boom was designed to fly tail high. Flying with the tail boom horizontal would
make the pilot feel as though he were laying on his back and climbing all the
time.
>
> My original Firestar was faster and flew slower than the FSII. It had full span
ailerons. The FSII is like the Kolbra with half span.
>
> I am a firm believer is extremely tight fabric. I believe this is one of the
major differences between air speed/flight characteristic differences of the
same model Kolbs. My MKIII has never been outrun by another MKIII. Same for
my original FS. Both aircraft had fabric that bowed the tubes on wings and empennage.
Soft fabric changes shape much more than tight fabric.
>
> There were a lot of things I would have liked to experiment with my Kolbs over
the last 32 years, but age caught up with me before I got them all done. Then
I got to the stage that what I have now is great. It does what I need. It
is an 85 mph cruise aircraft. If I can find a 15 mph tailwind, then I've got
a temporary 100 mph airplane across the ground. It will carry everything I can
cram into it to keep me and it going for extended periods of time. So far,
the longest duration flight was 48 days. The longest flight was 17,400 sm in
41 days and 232.0 flight hours. It will keep me in the air for 5 hours, if I
could do that without wetting my pants. It gets me in and out of tiny fields,
two track trails, gravel bars, beaches on the Atlantic, the Gulf of Mexico,
the Arctic Ocean, and small dry lakes in the dessert. It does much more than
Homer Kolb and John Hauck ever dreamed one of his little airplanes would do.
It takes me where I want to go. All I have to do is put gas in it, take off and
point the nose in that direction.
>
> john h
> mkIII
> Titus, Alabama
>
>
>
> -----Original Message-----
> From: owner-kolb-list-server(at)matronics.com [mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Bill Berle
> Sent: Thursday, March 17, 2016 3:01 AM
> To: kolb-list(at)matronics.com
> Subject: RE: FW: Kolb-List: FireStar 2 Kit Received !
>
>
> I have no Kolb experience whatsoever. This is my first Kolb. So some of my ideas
may not work out as well as I hope, and some of them may work better than
I imagined. The challenge and enjoyment of improving the performance of an already
good airplane is one of the things I'm looking forward to.
>
> I have a specific question which you might be able to answer: If you put the
wing on a FireStar at the lower incidence angle of the Slingshot, and then put
on the taller gear from the Slingshot, would you get both benefits (a higher
cruise speed from the tailboom flying straight), AND better STOL performance (from
the higher ground angle)?
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-profit entities
>
> --------------------------------------------
> On Wed, 3/16/16, John Hauck wrote:
>
> Subject: RE: FW: Kolb-List: FireStar 2 Kit Received !
> To: kolb-list(at)matronics.com
> Date: Wednesday, March 16, 2016, 8:03 PM
>
> "John Hauck"
>
> Hi Folks:
>
> The paragraphs in quotation marks are Bill B's.
>
> Homer Kolb didn't design the Kolbra. That aircraft was designed and built some
time after the original Kolb Aircraft Co was sold.
>
> "Mr. Kolb himself changed the wing dimensions to create the Slingshot, Kolbra,
Firelfy, and others. He also changed the angle of incidence (wing mounting
angle) to create different characteristics on different models."
>
> All Kolb wing dimensions are the same, except length of the wing panel. Shape
of the rib and cord is the same on all models.
>
> The Slingshot had less incidence because of the high main gear and the nose
high attitude the aircraft sat on the ground. It also flew faster, pulling the
tail boom parallel through the air stream. At slower speeds the SS really
drags its tail. Very tail low. Other Kolb models fly tail high because
of the excessive incidence.
>
> "Raked wingtips are shown to work, especially at high AoA and low speeds. They
create a pressure field that slightly reduces the wingtip vortex."
>
> I think you will find that Homer's wingtip takes care of the above.
>
> "VG's are shown to work great, especially on simple turbulent flow airfoils
like the Cub, Kolb, and Aeronca.
> They help the airflow stay attached to the wing at higher AoA. This results
in better control authority at low speeds, which will be a lifesaver in off-airport
STOL operations."
>
> All Kolb models have excellent low speed flight characteristics without VGs.
About the only thing I have been able to determine with the addition of VGs
on a Kolb is more gentle break on landing, and slightly less stall speed.
>
> "Mr. Kolb designed the landing gear to be as easy and low-risk for new or low-time
pilots as possible. It worked, and the Kolb has a wonderful reputation
for easy ground handling. This is just what the doctor ordered for a kit plane
that was safe for low time pilots. But this mellow ground handling comes
at the cost of losing the ideal ground angle for the wing to take off and land
slower. A longer or taller landing gear requires a slightly more experienced
pilot, but you get better STOL performance in the bargain."
>
> The Hauck Brothers have been designing and building "tall"
> landing gear for Kolb aircraft for 30 years. We put the first pair of heat
treated 4130 legs on a Kolb. The main reason we started experimenting with long
legs on my FS was the lack of brakes. One of the first mods to my FS was
4130 streamlined lift struts. They cleaned up the FS so much I couldn't get
it stopped on my short grass strip. The 36" legs turned the bottom of the
wing up more and helped slow the FS down on landing. They also made nice springs,
and worked wonders for softening up the suspension.
>
> BTW Bill B, tell us about your Kolb experience, please.
>
> john h
> mkIII
> Titus, Alabama
>
>
>
>
>
>
>
>
>
>
> Lists This Month --
> Some AWESOME FREE Gifts!)
> Raiser. Click on
> more about
> Gifts provided
> www.buildersbooks.com
> -Matt
> Dralle, List Admin.
> Forum -
> - MATRONICS WEB FORUMS -
> List Contribution Web Site -
> -Matt
> Dralle, List Admin.
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Kolb-List Digest: 3 Msgs - 03/17/16 |
| From: | B Young <byoungplumbing(at)gmail.com> |
I have a specific question which you might be able to answer: If you put
the wing
on a FireStar at the lower incidence angle of the Slingshot, and then put on
the taller gear from the Slingshot, would you get both benefits (a higher
cruise
speed from the tailboom flying straight), AND better STOL performance (from
the higher ground angle)?
Xxxxxxxxxxxxxxxxxxxxx
I don't think the tail boom has a lot more drag flying tail high vs
level. It is such a small angle I believe it to have a laminar flow.
Could it be possible that longer gear legs at 90 deg to the air flow would
have more drag than the tail boom at a small angle? Especially considering
the tail boom is flying in disturbed air from the fusealage/prop wash.
Check the airlines. The back quarter of the cabin area is racked up at a
greater angle than the Kolb tail boom in flight. Some of the reason is for
ground clearance when they rotate, but if the drag increase was so high
caused by the angle. They would decrease the angle and increase rotation
speed.
If you change the wing incidence, you need to change the incidence of the
horizontal tail plane. Engine mounting angle..,. At any given speed and
angle of attack there is only so much lift. Now if you change the wing
profile,,,,, you could get some benefits in some areas, but at the same
time you would loose benefits in other areas... Ex. To get a faster
cruise. You loose slow speed on take off and landing/ slower climb....
Pick what you want, but be prepared to pay.
To use John's idea of the other day,,,,, if you design a plane that will
take off and land at 25 mph, climb at 2500 fpm, cruise at 225 mph and the
engine only burn 1gph. Keeping the cost under fifty thousand......
Every pilot in the country would want one.
Boyd Young
________________________________________________________________________________
| From: | Patrick Ladd <patrickjladd(at)hotmail.com> |
I may be sticking my neck out here and asking get slapped down but will
someone explain why having longer legs increases the STOL capability of
our a/c. Excepting of course the case where you deliberately hold the
tail down on take off.
I agree with all the advantages which John listed, more wing area
exposed thus slowing landing run etc. However the first thing which
most of us do on take off is to get the tail up into flying position
thus reducing drag and allowing increased acceleration. When the tail is
up the the length of the u/c is irrelevant. In fact having the extra
wing area exposed by having long legs slows the planes acceleration for
exactly the same reason that it shortens the landing run.
When the plane is up on two wheels the AOA is that which was designed
in.
Comments about commercial a/c are largely irrelevant as they are
(mainly) tricycle gear and the wing is in flying position (more or less)
the whole time.
There may be good reasons for making u/c legs longer but I am not
convinced that STOL is one of them except the `keep the skid on the
ground until she drags herself off` scenario which I mentioned..
Enlightenment please.
Pat
________________________________________________________________________________
| From: | "Richard Pike" <thegreybaron(at)charter.net> |
Make the gear legs long enough and your fat friends will not be able to get in.
Which enables the airplane to get off the ground quicker.
Glad to help out.
--------
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0
Would you consider yourself to be a good person?
https://www.youtube.com/watch?v=VWcDXT6pH7A
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=453919#453919
________________________________________________________________________________
| From: | Charlie England <ceengland7(at)gmail.com> |
On Sat, Mar 19, 2016 at 5:58 AM, Patrick Ladd
wrote:
> I may be sticking my neck out here and asking get slapped down but will
> someone explain why having longer legs increases the STOL capability of our
> a/c. Excepting of course the case where you deliberately hold the tail down
> on take off.
> I agree with all the advantages which John listed, more wing area exposed
> thus slowing landing run etc. However the first thing which most of us do
> on take off is to get the tail up into flying position thus reducing drag
> and allowing increased acceleration. When the tail is up the the length of
> the u/c is irrelevant. In fact having the extra wing area exposed by having
> long legs slows the planes acceleration for exactly the same reason that it
> shortens the landing run.
> When the plane is up on two wheels the AOA is that which was designed in.
> Comments about commercial a/c are largely irrelevant as they are (mainly)
> tricycle gear and the wing is in flying position (more or less) the whole
> time.
> There may be good reasons for making u/c legs longer but I am not
> convinced that STOL is one of them except the `keep the skid on the ground
> until she drags herself off` scenario which I mentioned..
> Enlightenment please.
> Pat
>
I'll take a crack at it, in general terms. You can decide if it applies to
Kolbs.
If you watch videos of hard core bush flying, the pilot will hold the
brakes and raise the tail prior to starting the takeoff roll (to minimize
wing drag, as you point out). When he's got max available power, he
releases the brakes. As soon as he's got minimum flying speed, he rotates &
the plane jumps into the air. Now, most taildraggers sit on the ground with
the wing at a significantly lower angle than critical (stall) AOA. So in
stock condition, they can't be rotated to lift off at anywhere near stall
speed. So, their minimum speed for takeoff is limited (made higher) by the
length of the main gear legs. If the same trick is tried with 'short legs',
the pilot would slam the tailwheel into the ground when he rotates. FWIW,
there are videos of airliners actually dragging the rear of the fuselage on
the ground when they over-rotate. Airliners (at least some of them)
actually give up significant landing speed reduction because they don't
want the weight of long gear legs when they always have plenty of runway
for 'driving it on' in landing.
In landing mode, it's just as important. In normal flying, a pilot would
try to '3 point', having the mains & tailwheel touch at the same time to
land at minimum airspeed. But, since the wing isn't at critical AOA in 3
point attitude, he's not really landing at minimum airspeed. If the mains
were longer, he could land slower. In bush flying, it gets worse. Again,
watching extreme bush flying, you'll see the pilot wheel land and keep the
tail off the ground until he's almost stopped. With a typical taildragger,
he's carrying quite a bit of extra airspeed to 'wheel land' the plane, but
he does it to protect the tailwheel from damage, from rough ground and from
impact damage of dropping it in. If the legs are extended enough, he can
have full stall AOA available from the wing, without the tailwheel being on
the ground. Obviously, this will let him land slower & shorter.
Does any of that apply to Kolbs?
________________________________________________________________________________
| From: | Patrick Ladd <patrickjladd(at)hotmail.com> |
Thanks Charlie,
i can see the reasoning and in fact I saw a guy up in Fairbanks in a
Super Cub pulling the `tail up, full throttle trick`. He powered up,
standing on the brakes, hauled it off the ground by pushing the tail
down and climbing out at just above stall speed.. He did a circuit and
landed again, tail down and hanging on his prop at full chat, like a
helicopter. All in an incredibly short time. I filmed it with a video
camera in one take.
I somehow doubt that many Kolbers have the brakes, to be able to come
close to emulating that performance. Without some actual measurements it
is impossible to calculate accurately the increased AOA available and I
was never any good at trig anyway but assuming 10ft between mains and
tail wheel and an increase in height of the gear legs of say 4 inches,
by how many degrees does that increase the AOA? 1 degree? 1.5 degrees.?
No doubt someone on the list will work it out.
It may well be worth extending legs for other reasons but STOL?.
Questionable.
Pat
From: Charlie England
Sent: Saturday, March 19, 2016 1:34 PM
Subject: Re: Kolb-List: long legs
On Sat, Mar 19, 2016 at 5:58 AM, Patrick Ladd
wrote:
I may be sticking my neck out here and asking get slapped down but
will someone explain why having longer legs increases the STOL
capability of our a/c. Excepting of course the case where you
deliberately hold the tail down on take off.
I agree with all the advantages which John listed, more wing area
exposed thus slowing landing run etc. However the first thing which
most of us do on take off is to get the tail up into flying position
thus reducing drag and allowing increased acceleration. When the tail is
up the the length of the u/c is irrelevant. In fact having the extra
wing area exposed by having long legs slows the planes acceleration for
exactly the same reason that it shortens the landing run.
When the plane is up on two wheels the AOA is that which was designed
in.
Comments about commercial a/c are largely irrelevant as they are
(mainly) tricycle gear and the wing is in flying position (more or less)
the whole time.
There may be good reasons for making u/c legs longer but I am not
convinced that STOL is one of them except the `keep the skid on the
ground until she drags herself off` scenario which I mentioned..
Enlightenment please.
Pat
I'll take a crack at it, in general terms. You can decide if it applies
to Kolbs.
If you watch videos of hard core bush flying, the pilot will hold the
brakes and raise the tail prior to starting the takeoff roll (to
minimize wing drag, as you point out). When he's got max available
power, he releases the brakes. As soon as he's got minimum flying speed,
he rotates & the plane jumps into the air. Now, most taildraggers sit on
the ground with the wing at a significantly lower angle than critical
(stall) AOA. So in stock condition, they can't be rotated to lift off at
anywhere near stall speed. So, their minimum speed for takeoff is
limited (made higher) by the length of the main gear legs. If the same
trick is tried with 'short legs', the pilot would slam the tailwheel
into the ground when he rotates. FWIW, there are videos of airliners
actually dragging the rear of the fuselage on the ground when they
over-rotate. Airliners (at least some of them) actually give up
significant landing speed reduction because they don't want the weight
of long gear legs when they always have plenty of runway for 'driving it
on' in landing.
In landing mode, it's just as important. In normal flying, a pilot would
try to '3 point', having the mains & tailwheel touch at the same time to
land at minimum airspeed. But, since the wing isn't at critical AOA in 3
point attitude, he's not really landing at minimum airspeed. If the
mains were longer, he could land slower. In bush flying, it gets worse.
Again, watching extreme bush flying, you'll see the pilot wheel land and
keep the tail off the ground until he's almost stopped. With a typical
taildragger, he's carrying quite a bit of extra airspeed to 'wheel land'
the plane, but he does it to protect the tailwheel from damage, from
rough ground and from impact damage of dropping it in. If the legs are
extended enough, he can have full stall AOA available from the wing,
without the tailwheel being on the ground. Obviously, this will let him
land slower & shorter.
Does any of that apply to Kolbs?
________________________________________________________________________________
| From: | Charlie England <ceengland7(at)gmail.com> |
Since typical AOA is around 14-15 degrees at stall, a 1.5 degree increase
could be close to a 10% increase in 3 point attitude. Not something to
sneeze at.
Again, you must decide if it applies to Kolbs, and whether it actually
matters to you for your style of flying. Who would think that a stock Super
Cub needed shorter field performance, but a lot of bush fliers obviously
consider it inadequate for their purposes.
On Sat, Mar 19, 2016 at 9:40 AM, Patrick Ladd
wrote:
> Thanks Charlie,
> i can see the reasoning and in fact I saw a guy up in Fairbanks in a Super
> Cub pulling the `tail up, full throttle trick`. He powered up, standing on
> the brakes, hauled it off the ground by pushing the tail down and climbing
> out at just above stall speed.. He did a circuit and landed again, tail
> down and hanging on his prop at full chat, like a helicopter. All in an
> incredibly short time. I filmed it with a video camera in one take.
> I somehow doubt that many Kolbers have the brakes, to be able to come
> close to emulating that performance. Without some actual measurements it is
> impossible to calculate accurately the increased AOA available and I was
> never any good at trig anyway but assuming 10ft between mains and tail
> wheel and an increase in height of the gear legs of say 4 inches, by how
> many degrees does that increase the AOA? 1 degree? 1.5 degrees.? No doubt
> someone on the list will work it out.
> It may well be worth extending legs for other reasons but STOL?.
> Questionable.
>
> Pat
>
> *From:* Charlie England
> *Sent:* Saturday, March 19, 2016 1:34 PM
> *To:* kolb-list(at)matronics.com
> *Subject:* Re: Kolb-List: long legs
>
>
> On Sat, Mar 19, 2016 at 5:58 AM, Patrick Ladd
> wrote:
>
>> I may be sticking my neck out here and asking get slapped down but will
>> someone explain why having longer legs increases the STOL capability of our
>> a/c. Excepting of course the case where you deliberately hold the tail down
>> on take off.
>> I agree with all the advantages which John listed, more wing area exposed
>> thus slowing landing run etc. However the first thing which most of us do
>> on take off is to get the tail up into flying position thus reducing drag
>> and allowing increased acceleration. When the tail is up the the length of
>> the u/c is irrelevant. In fact having the extra wing area exposed by having
>> long legs slows the planes acceleration for exactly the same reason that it
>> shortens the landing run.
>> When the plane is up on two wheels the AOA is that which was designed in.
>> Comments about commercial a/c are largely irrelevant as they are (mainly)
>> tricycle gear and the wing is in flying position (more or less) the whole
>> time.
>> There may be good reasons for making u/c legs longer but I am not
>> convinced that STOL is one of them except the `keep the skid on the ground
>> until she drags herself off` scenario which I mentioned..
>> Enlightenment please.
>> Pat
>>
>
> I'll take a crack at it, in general terms. You can decide if it applies to
> Kolbs.
>
> If you watch videos of hard core bush flying, the pilot will hold the
> brakes and raise the tail prior to starting the takeoff roll (to minimize
> wing drag, as you point out). When he's got max available power, he
> releases the brakes. As soon as he's got minimum flying speed, he rotates &
> the plane jumps into the air. Now, most taildraggers sit on the ground with
> the wing at a significantly lower angle than critical (stall) AOA. So in
> stock condition, they can't be rotated to lift off at anywhere near stall
> speed. So, their minimum speed for takeoff is limited (made higher) by the
> length of the main gear legs. If the same trick is tried with 'short legs',
> the pilot would slam the tailwheel into the ground when he rotates. FWIW,
> there are videos of airliners actually dragging the rear of the fuselage on
> the ground when they over-rotate. Airliners (at least some of them)
> actually give up significant landing speed reduction because they don't
> want the weight of long gear legs when they always have plenty of runway
> for 'driving it on' in landing.
>
> In landing mode, it's just as important. In normal flying, a pilot would
> try to '3 point', having the mains & tailwheel touch at the same time to
> land at minimum airspeed. But, since the wing isn't at critical AOA in 3
> point attitude, he's not really landing at minimum airspeed. If the mains
> were longer, he could land slower. In bush flying, it gets worse. Again,
> watching extreme bush flying, you'll see the pilot wheel land and keep the
> tail off the ground until he's almost stopped. With a typical taildragger,
> he's carrying quite a bit of extra airspeed to 'wheel land' the plane, but
> he does it to protect the tailwheel from damage, from rough ground and from
> impact damage of dropping it in. If the legs are extended enough, he can
> have full stall AOA available from the wing, without the tailwheel being on
> the ground. Obviously, this will let him land slower & shorter.
>
> Does any of that apply to Kolbs?
>
________________________________________________________________________________
| From: | Patrick Ladd <patrickjladd(at)hotmail.com> |
Good point Richard.
In general my fat friends did not get a look in. Fat girls now.....Pat
-----Original Message-----
From: Richard Pike
Sent: Saturday, March 19, 2016 11:24 AM
Subject: Kolb-List: Re: long legs
Make the gear legs long enough and your fat friends will not be able to get
in. Which enables the airplane to get off the ground quicker.
Glad to help out.
--------
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0
Would you consider yourself to be a good person?
https://www.youtube.com/watch?v=VWcDXT6pH7A
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=453919#453919
________________________________________________________________________________
| From: | Theodore Cowan <tc1917(at)bellsouth.net> |
The slingshot has long legs to facilitate 9 degrees AOA. Most have 12 degrees
AOA. That gives the SS remarkable speed capabilities without the boom raising
up. I can cruise at 90/100 without problems. As Hauck mentioned, the boom does
drop but not until around 60. Still not a problem. I believe if you put longer
gear on a standard firestar you would have difficult ground handling and you
might have lift off before rotation. The SS has to rotate quickly and then
has to drop its tail to get proper AOA which brings the tail down considerably.
Landing slow the tail is in a three point configuration to get back to 12
degrees AOA. You can land the SS high on the mains but landing roll is faster.
Not sure if the firefly has the same or not. I am sure of one thing, the SS
is the fastest, most sensitive aircraft of the bunch. With a rotax 912 80 hp
on her back, it is a rocket. Abt two hundred ft on the ground, less than three
to land and cuts through the bumps and zips around like it it is on a tether.
Not for the average bear but a ball when you master it. Best of the kolbs
i think. It would be nice the have the baggage capabilities as Hauck does!
Ted Cowan slingshot 912 zoom zoom
Sent from my iPhone
________________________________________________________________________________
| Subject: | Re: FireStar 2 Kit Received ! |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Bill, IMOH powder coating is great for patio furniture, office machinery,
and other expendibles, but is not suitable for an airframe. It looks great
straight out of the oven, but once it gets some time on it cracks form
letting moisture in and brown streaks, just like those you are seeing on
your airframe, begin to form. The only solution is to grind it off and
patch it with paint.
I much prefer two part epoxy paint (urethanes, like Aerothane, release
cyanide gas so you must have an air supply to shoot them). You can get it
from O'Reilly's Auto Parts (about $40 a quart)
http://www.oreillyauto.com/site/c/detail/TRS2/6101/N2541.oap?ck=Search_N2
541_-1_-1&pt=N2541&ppt=C0171
and the small gun in the Harbor Freight HVLP set (usually about $45) works
great for tubes;
http://www.harborfreight.com/air-tools/paint/2-pc-professional-automotive-h
vlp-air-spray-gun-kit-61472.html
Give it at least four days to fully harden before applying fabric if using
the Poly Fiber system so the solvents won't attack the epoxy. Now you have
something you can repair as necessary.
Anyway, that's what I use and I like it. Also works great on aluminum parts
if you alodine them first.
Rick Girard
On Thu, Mar 17, 2016 at 7:24 PM, Dennis Rowe
wrote:
>
> Man, let me know if you ever want to sell Miss Pfer. =F0=9F=94=BD=F0=9F
=94=BD that was quite
> the sales pitch!
>
> Dennis "Skid" Rowe
>
>
> > On Mar 17, 2016, at 9:22 AM, John Hauck wrote:
> >
> > I always thought dragging the tail boom straight, instead of sideways
> through the air, would clean it up a bit and increase cruise. The SS and
> Kolbra utilize that design technique with lower incidence to increase
> cruise. John Williamson's Kolbra, with 912ULS, same engine on my MKIII,
> cruised 10 mph faster at the same rpm. Top speed is about 10 to 15 mph
> quicker. The major difference in drag between the Kolbra/SS and the MKII
I
> was the difference between the width and shape of the fuselage. Also, th
e
> Kolbra had less wing area because it did not have flaps. The MKIII flies
> slower and gets off the ground quicker.
> >
> > Actually, the fuselage of the FS would have to be redesigned because th
e
> tail boom was designed to fly tail high. Flying with the tail boom
> horizontal would make the pilot feel as though he were laying on his back
> and climbing all the time.
> >
> > My original Firestar was faster and flew slower than the FSII. It had
> full span ailerons. The FSII is like the Kolbra with half span.
> >
> > I am a firm believer is extremely tight fabric. I believe this is one
> of the major differences between air speed/flight characteristic
> differences of the same model Kolbs. My MKIII has never been outrun by
> another MKIII. Same for my original FS. Both aircraft had fabric that
> bowed the tubes on wings and empennage. Soft fabric changes shape much
> more than tight fabric.
> >
> > There were a lot of things I would have liked to experiment with my
> Kolbs over the last 32 years, but age caught up with me before I got them
> all done. Then I got to the stage that what I have now is great. It doe
s
> what I need. It is an 85 mph cruise aircraft. If I can find a 15 mph
> tailwind, then I've got a temporary 100 mph airplane across the ground.
It
> will carry everything I can cram into it to keep me and it going for
> extended periods of time. So far, the longest duration flight was 48
> days. The longest flight was 17,400 sm in 41 days and 232.0 flight hours
.
> It will keep me in the air for 5 hours, if I could do that without wettin
g
> my pants. It gets me in and out of tiny fields, two track trails, gravel
> bars, beaches on the Atlantic, the Gulf of Mexico, the Arctic Ocean, and
> small dry lakes in the dessert. It does much more than Homer Kolb and Jo
hn
> Hauck ever dreamed one of his little airplanes would do. It takes me whe
re
> I want to go. All I have to do is!
> put gas in it, take off and point the nose in that direction.
> >
> > john h
> > mkIII
> > Titus, Alabama
> >
> >
> >
> > -----Original Message-----
> > From: owner-kolb-list-server(at)matronics.com [mailto:
> owner-kolb-list-server(at)matronics.com] On Behalf Of Bill Berle
> > Sent: Thursday, March 17, 2016 3:01 AM
> > To: kolb-list(at)matronics.com
> > Subject: RE: FW: Kolb-List: FireStar 2 Kit Received !
> >
> >
> > I have no Kolb experience whatsoever. This is my first Kolb. So some of
> my ideas may not work out as well as I hope, and some of them may work
> better than I imagined. The challenge and enjoyment of improving the
> performance of an already good airplane is one of the things I'm looking
> forward to.
> >
> > I have a specific question which you might be able to answer: If you pu
t
> the wing on a FireStar at the lower incidence angle of the Slingshot, and
> then put on the taller gear from the Slingshot, would you get both benefi
ts
> (a higher cruise speed from the tailboom flying straight), AND better STO
L
> performance (from the higher ground angle)?
> >
> > Bill Berle
> > www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and
> for-profit entities
> >
> > --------------------------------------------
> > On Wed, 3/16/16, John Hauck wrote:
> >
> > Subject: RE: FW: Kolb-List: FireStar 2 Kit Received !
> > To: kolb-list(at)matronics.com
> > Date: Wednesday, March 16, 2016, 8:03 PM
> >
> > "John Hauck"
> >
> > Hi Folks:
> >
> > The paragraphs in quotation marks are Bill B's.
> >
> > Homer Kolb didn't design the Kolbra. That aircraft was designed and
> built some time after the original Kolb Aircraft Co was sold.
> >
> > "Mr. Kolb himself changed the wing dimensions to create the Slingshot,
> Kolbra, Firelfy, and others. He also changed the angle of incidence (win
g
> mounting angle) to create different characteristics on different models.
"
> >
> > All Kolb wing dimensions are the same, except length of the wing
> panel. Shape of the rib and cord is the same on all models.
> >
> > The Slingshot had less incidence because of the high main gear and the
> nose high attitude the aircraft sat on the ground. It also flew faster,
> pulling the tail boom parallel through the air stream. At slower speeds
> the SS really drags its tail. Very tail low. Other Kolb models fly
> tail high because of the excessive incidence.
> >
> > "Raked wingtips are shown to work, especially at high AoA and low
> speeds. They create a pressure field that slightly reduces the wingtip
> vortex."
> >
> > I think you will find that Homer's wingtip takes care of the above.
> >
> > "VG's are shown to work great, especially on simple turbulent flow
> airfoils like the Cub, Kolb, and Aeronca.
> > They help the airflow stay attached to the wing at higher AoA. This
> results in better control authority at low speeds, which will be a
> lifesaver in off-airport STOL operations."
> >
> > All Kolb models have excellent low speed flight characteristics withou
t
> VGs. About the only thing I have been able to determine with the additi
on
> of VGs on a Kolb is more gentle break on landing, and slightly less sta
ll
> speed.
> >
> > "Mr. Kolb designed the landing gear to be as easy and low-risk for new
> or low-time pilots as possible. It worked, and the Kolb has a wonderful
> reputation for easy ground handling. This is just what the doctor ordere
d
> for a kit plane that was safe for low time pilots. But this mellow grou
nd
> handling comes at the cost of losing the ideal ground angle for the win
g
> to take off and land slower. A longer or taller landing gear requires a
> slightly more experienced pilot, but you get better STOL performance in
> the bargain."
> >
> > The Hauck Brothers have been designing and building "tall"
> > landing gear for Kolb aircraft for 30 years. We put the first pair of
> heat treated 4130 legs on a Kolb. The main reason we started experimenti
ng
> with long legs on my FS was the lack of brakes. One of the first mods t
o
> my FS was 4130 streamlined lift struts. They cleaned up the FS so much
I
> couldn't get it stopped on my short grass strip. The 36" legs turned th
e
> bottom of the wing up more and helped slow the FS down on landing. They
> also made nice springs, and worked wonders for softening up the suspensi
on.
> >
> > BTW Bill B, tell us about your Kolb experience, please.
> >
> > john h
> > mkIII
> > Titus, Alabama
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Lists This Month --
> > Some AWESOME FREE Gifts!)
> > Raiser. Click on
> > more about
> > Gifts provided
> > www.buildersbooks.com
> > -Matt
> > Dralle, List Admin.
> > Forum -
> > - MATRONICS WEB FORUMS -
> > List Contribution Web Site -
> > -Matt
> > Dralle, List Admin.
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
===========
===========
===========
===========
===========
>
>
--
=9CBlessed are the cracked, for they shall let in the light.=9D
Groucho Marx
<http://www.goodreads.com/author/show/43244.Groucho_Marx>
________________________________________________________________________________
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Patrick, My Mk III has aluminum legs, my friend's Mk IIIX has steel legs
and lower wing incidence. Neither can get a full stall landing. If I do I
land tail wheel first. Perhaps a full stall landing could be achieved with
longer legs and higher incidence. When I get my Mk III rebuilt perhaps I'll
know.
Rick Girard
On Sat, Mar 19, 2016 at 10:26 AM, Charlie England
wrote:
> Since typical AOA is around 14-15 degrees at stall, a 1.5 degree increase
> could be close to a 10% increase in 3 point attitude. Not something to
> sneeze at.
>
> Again, you must decide if it applies to Kolbs, and whether it actually
> matters to you for your style of flying. Who would think that a stock Sup
er
> Cub needed shorter field performance, but a lot of bush fliers obviously
> consider it inadequate for their purposes.
>
> On Sat, Mar 19, 2016 at 9:40 AM, Patrick Ladd
> wrote:
>
>> Thanks Charlie,
>> i can see the reasoning and in fact I saw a guy up in Fairbanks in a
>> Super Cub pulling the `tail up, full throttle trick`. He powered up,
>> standing on the brakes, hauled it off the ground by pushing the tail dow
n
>> and climbing out at just above stall speed.. He did a circuit and landed
>> again, tail down and hanging on his prop at full chat, like a helicopte
r.
>> All in an incredibly short time. I filmed it with a video camera in one
>> take.
>> I somehow doubt that many Kolbers have the brakes, to be able to come
>> close to emulating that performance. Without some actual measurements it
is
>> impossible to calculate accurately the increased AOA available and I was
>> never any good at trig anyway but assuming 10ft between mains and tail
>> wheel and an increase in height of the gear legs of say 4 inches, by how
>> many degrees does that increase the AOA? 1 degree? 1.5 degrees.? No doub
t
>> someone on the list will work it out.
>> It may well be worth extending legs for other reasons but STOL?.
>> Questionable.
>>
>> Pat
>>
>> *From:* Charlie England
>> *Sent:* Saturday, March 19, 2016 1:34 PM
>> *To:* kolb-list(at)matronics.com
>> *Subject:* Re: Kolb-List: long legs
>>
>>
>>
>> On Sat, Mar 19, 2016 at 5:58 AM, Patrick Ladd
>> wrote:
>>
>>> I may be sticking my neck out here and asking get slapped down but will
>>> someone explain why having longer legs increases the STOL capability of
our
>>> a/c. Excepting of course the case where you deliberately hold the tail
down
>>> on take off.
>>> I agree with all the advantages which John listed, more wing area
>>> exposed thus slowing landing run etc. However the first thing which mo
st
>>> of us do on take off is to get the tail up into flying position thus
>>> reducing drag and allowing increased acceleration. When the tail is up
the
>>> the length of the u/c is irrelevant. In fact having the extra wing area
>>> exposed by having long legs slows the planes acceleration for exactly t
he
>>> same reason that it shortens the landing run.
>>> When the plane is up on two wheels the AOA is that which was designed i
n.
>>> Comments about commercial a/c are largely irrelevant as they are
>>> (mainly) tricycle gear and the wing is in flying position (more or less
)
>>> the whole time.
>>> There may be good reasons for making u/c legs longer but I am not
>>> convinced that STOL is one of them except the `keep the skid on the gr
ound
>>> until she drags herself off` scenario which I mentioned..
>>> Enlightenment please.
>>> Pat
>>>
>>
>> I'll take a crack at it, in general terms. You can decide if it applies
>> to Kolbs.
>>
>> If you watch videos of hard core bush flying, the pilot will hold the
>> brakes and raise the tail prior to starting the takeoff roll (to minimiz
e
>> wing drag, as you point out). When he's got max available power, he
>> releases the brakes. As soon as he's got minimum flying speed, he rotate
s &
>> the plane jumps into the air. Now, most taildraggers sit on the ground w
ith
>> the wing at a significantly lower angle than critical (stall) AOA. So in
>> stock condition, they can't be rotated to lift off at anywhere near stal
l
>> speed. So, their minimum speed for takeoff is limited (made higher) by t
he
>> length of the main gear legs. If the same trick is tried with 'short leg
s',
>> the pilot would slam the tailwheel into the ground when he rotates. FWIW
,
>> there are videos of airliners actually dragging the rear of the fuselage
on
>> the ground when they over-rotate. Airliners (at least some of them)
>> actually give up significant landing speed reduction because they don't
>> want the weight of long gear legs when they always have plenty of runway
>> for 'driving it on' in landing.
>>
>> In landing mode, it's just as important. In normal flying, a pilot would
>> try to '3 point', having the mains & tailwheel touch at the same time to
>> land at minimum airspeed. But, since the wing isn't at critical AOA in 3
>> point attitude, he's not really landing at minimum airspeed. If the main
s
>> were longer, he could land slower. In bush flying, it gets worse. Again,
>> watching extreme bush flying, you'll see the pilot wheel land and keep t
he
>> tail off the ground until he's almost stopped. With a typical taildragge
r,
>> he's carrying quite a bit of extra airspeed to 'wheel land' the plane, b
ut
>> he does it to protect the tailwheel from damage, from rough ground and f
rom
>> impact damage of dropping it in. If the legs are extended enough, he can
>> have full stall AOA available from the wing, without the tailwheel being
on
>> the ground. Obviously, this will let him land slower & shorter.
>>
>> Does any of that apply to Kolbs?
>>
>
>
--
=9CBlessed are the cracked, for they shall let in the light.=9D
Groucho Marx
<http://www.goodreads.com/author/show/43244.Groucho_Marx>
________________________________________________________________________________
| From: | Patrick Ladd <patrickjladd(at)hotmail.com> |
I look forward to a definitive statement.
The guy in the Super Cub, at full throttle, lowered his plane onto the
tail wheel at almost nil forward speed, cut back on the throttle and
then the mains crashed down onto its balloon bush tyres.Hard on the
system. Breaking my heart not to have a plane to fly any more. We have
had a week in the middle of a large High pressure system. Glorious
flying weather and me stuck here playing with a 18=9D diameter
quadrocopter my wife bought me fro Christmas.Oh! Bugger. Pat
From: Richard Girard
Sent: Monday, March 21, 2016 4:29 PM
Subject: Re: Kolb-List: long legs
Patrick, My Mk III has aluminum legs, my friend's Mk IIIX has steel legs
and lower wing incidence. Neither can get a full stall landing. If I do
I land tail wheel first. Perhaps a full stall landing could be achieved
with longer legs and higher incidence. When I get my Mk III rebuilt
perhaps I'll know.
Rick Girard
On Sat, Mar 19, 2016 at 10:26 AM, Charlie England
wrote:
Since typical AOA is around 14-15 degrees at stall, a 1.5 degree
increase could be close to a 10% increase in 3 point attitude. Not
something to sneeze at.
Again, you must decide if it applies to Kolbs, and whether it actually
matters to you for your style of flying. Who would think that a stock
Super Cub needed shorter field performance, but a lot of bush fliers
obviously consider it inadequate for their purposes.
On Sat, Mar 19, 2016 at 9:40 AM, Patrick Ladd
wrote:
Thanks Charlie,
i can see the reasoning and in fact I saw a guy up in Fairbanks in a
Super Cub pulling the `tail up, full throttle trick`. He powered up,
standing on the brakes, hauled it off the ground by pushing the tail
down and climbing out at just above stall speed.. He did a circuit and
landed again, tail down and hanging on his prop at full chat, like a
helicopter. All in an incredibly short time. I filmed it with a video
camera in one take.
I somehow doubt that many Kolbers have the brakes, to be able to
come close to emulating that performance. Without some actual
measurements it is impossible to calculate accurately the increased AOA
available and I was never any good at trig anyway but assuming 10ft
between mains and tail wheel and an increase in height of the gear legs
of say 4 inches, by how many degrees does that increase the AOA? 1
degree? 1.5 degrees.? No doubt someone on the list will work it out.
It may well be worth extending legs for other reasons but STOL?.
Questionable.
Pat
From: Charlie England
Sent: Saturday, March 19, 2016 1:34 PM
To: kolb-list(at)matronics.com
Subject: Re: Kolb-List: long legs
On Sat, Mar 19, 2016 at 5:58 AM, Patrick Ladd
wrote:
I may be sticking my neck out here and asking get slapped down but
will someone explain why having longer legs increases the STOL
capability of our a/c. Excepting of course the case where you
deliberately hold the tail down on take off.
I agree with all the advantages which John listed, more wing area
exposed thus slowing landing run etc. However the first thing which
most of us do on take off is to get the tail up into flying position
thus reducing drag and allowing increased acceleration. When the tail is
up the the length of the u/c is irrelevant. In fact having the extra
wing area exposed by having long legs slows the planes acceleration for
exactly the same reason that it shortens the landing run.
When the plane is up on two wheels the AOA is that which was
designed in.
Comments about commercial a/c are largely irrelevant as they are
(mainly) tricycle gear and the wing is in flying position (more or less)
the whole time.
There may be good reasons for making u/c legs longer but I am not
convinced that STOL is one of them except the `keep the skid on the
ground until she drags herself off` scenario which I mentioned..
Enlightenment please.
Pat
I'll take a crack at it, in general terms. You can decide if it
applies to Kolbs.
If you watch videos of hard core bush flying, the pilot will hold
the brakes and raise the tail prior to starting the takeoff roll (to
minimize wing drag, as you point out). When he's got max available
power, he releases the brakes. As soon as he's got minimum flying speed,
he rotates & the plane jumps into the air. Now, most taildraggers sit on
the ground with the wing at a significantly lower angle than critical
(stall) AOA. So in stock condition, they can't be rotated to lift off at
anywhere near stall speed. So, their minimum speed for takeoff is
limited (made higher) by the length of the main gear legs. If the same
trick is tried with 'short legs', the pilot would slam the tailwheel
into the ground when he rotates. FWIW, there are videos of airliners
actually dragging the rear of the fuselage on the ground when they
over-rotate. Airliners (at least some of them) actually give up
significant landing speed reduction because they don't want the weight
of long gear legs when they always have plenty of runway for 'driving it
on' in landing.
In landing mode, it's just as important. In normal flying, a pilot
would try to '3 point', having the mains & tailwheel touch at the same
time to land at minimum airspeed. But, since the wing isn't at critical
AOA in 3 point attitude, he's not really landing at minimum airspeed. If
the mains were longer, he could land slower. In bush flying, it gets
worse. Again, watching extreme bush flying, you'll see the pilot wheel
land and keep the tail off the ground until he's almost stopped. With a
typical taildragger, he's carrying quite a bit of extra airspeed to
'wheel land' the plane, but he does it to protect the tailwheel from
damage, from rough ground and from impact damage of dropping it in. If
the legs are extended enough, he can have full stall AOA available from
the wing, without the tailwheel being on the ground. Obviously, this
will let him land slower & shorter.
Does any of that apply to Kolbs?
--
=9CBlessed are the cracked, for they shall let in the
light.=9D Groucho Marx
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
>From my research, and hearing from other people who have been around Kolbs for
many many years, I think it is safe to say that Homer Kolb designed this series
of aircraft for good handling, good manners, and able to be flown easily by
a low time pilot. By all accounts he succeeded and created a fantastic little
airplane.
But physics do not lie... in order to be a great airplane in one area, design sacrifices
must be made in some other area. This is why a LearJet is not appropriate
for a low time pilot, and this is why a Cessna 172 is (usually) not very
exciting for a high time pilot. I have no doubt that Mr. Kolb understood this,
and chose safety/easy handling over maximum possible performance. The sales
and success of the Kolb fleet has proven him right.
The Kolbs are world renowned for being docile and not demanding. The price paid
for that is that some performance has been sacrificed.
Raising the ground angle high enough so that the airplane can perform a full-stall
3 point landing will clearly allow the airplane to realize the maximum STOL
performance that the wing and engine combination is capable of delivering. That
is basic textbook aeroduynamics. But since the Kolb apparently has good STOL
performance with the stock configuration, it's been a non-issue for the majority
of Kolb pilots.
Speaking ONLY for myself, I would like to maximize the STOL performance of my aircraft,
because I am heavier than an average pilot, and my airplane will not
meet the 254 UL weight either. So rather than having to put a $20K, 100HP engine
on it, I believe I will get 2/3 of the same benefit by having a tall enough
landing gear for the wing to fly sooner. The price I have to pay for that is
that I cannot be a low-time, beginner pilot, and the airplane will be a little
slower (higher drag and drag further underneath the CG).
The modifications that I am planning for my aircraft will not be for everyone.
But I'm hopeful that they will suit my needs.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Mon, 3/21/16, Richard Girard wrote:
Subject: Re: Kolb-List: long legs
To: "kolb-list(at)matronics.com"
Date: Monday, March 21, 2016, 9:29 AM
Patrick,
My Mk III has aluminum legs, my friend's Mk IIIX has
steel legs and lower wing incidence. Neither can get a full
stall landing. If I do I land tail wheel first. Perhaps a
full stall landing could be achieved with longer legs and
higher incidence. When I get my Mk III rebuilt perhaps
I'll know.
Rick
Girard
On Sat, Mar 19, 2016 at
10:26 AM, Charlie England
wrote:
Since typical AOA is around 14-15 degrees at
stall, a 1.5 degree increase could be close to a 10%
increase in 3 point attitude. Not something to sneeze
at.
Again, you must decide
if it applies to Kolbs, and whether it actually matters to
you for your style of flying. Who would think that a stock
Super Cub needed shorter field performance, but a lot of
bush fliers obviously consider it inadequate for their
purposes.
On Sat, Mar 19, 2016 at
9:40 AM, Patrick Ladd
wrote:
Thanks Charlie,
i can see the reasoning and in fact I saw a guy up in
Fairbanks in a Super
Cub pulling the `tail up, full throttle trick`. He powered
up, standing on the
brakes, hauled it off the ground by pushing the tail down
and climbing out at
just above stall speed.. He did a circuit and landed again,
tail down and
hanging on his prop at full chat, like a helicopter. All
in an incredibly
short time. I filmed it with a video camera in one
take.
I somehow doubt that many Kolbers have the brakes, to
be able to come close
to emulating that performance. Without some actual
measurements it is impossible
to calculate accurately the increased AOA available and I
was never any good at
trig anyway but assuming 10ft between mains and tail wheel
and an increase in
height of the gear legs of say 4 inches, by how many degrees
does that increase
the AOA? 1 degree? 1.5 degrees.? No doubt someone on the
list will work it
out.
It may well be worth extending legs for other reasons
but STOL?.
Questionable.
Pat
From: Charlie
England
Sent: Saturday, March 19, 2016 1:34 PM
To: kolb-list(at)matronics.com
Subject: Re: Kolb-List: long
legs
On Sat, Mar 19, 2016
at 5:58 AM, Patrick Ladd
wrote:
I may be sticking my neck out here and asking get
slapped down but will
someone explain why having longer legs increases the STOL
capability of our
a/c. Excepting of course the case where you deliberately
hold the tail down on
take off.
I agree with all the advantages which John listed,
more wing area exposed
thus slowing landing run etc. However the first thing
which most of us
do on take off is to get the tail up into flying position
thus reducing drag
and allowing increased acceleration. When the tail is up
the the length of the
u/c is irrelevant. In fact having the extra wing area
exposed by having long
legs slows the planes acceleration for exactly the same
reason that it
shortens the landing run.
When the plane is up on two wheels the AOA is that
which was designed
in.
Comments about commercial a/c are largely irrelevant
as they are (mainly)
tricycle gear and the wing is in flying position (more or
less) the whole
time.
There may be good reasons for making u/c legs longer
but I am not
convinced that STOL is one of them except the `keep the
skid on the
ground until she drags herself off` scenario which I
mentioned..
Enlightenment please.
Pat
I'll take a crack
at it, in general terms. You can decide
if it applies to Kolbs.
If you watch videos of
hard core bush flying, the pilot
will hold the brakes and raise the tail prior to starting
the takeoff roll (to
minimize wing drag, as you point out). When he's got max
available power, he
releases the brakes. As soon as he's got minimum flying
speed, he rotates &
the plane jumps into the air. Now, most taildraggers sit on
the ground with the
wing at a significantly lower angle than critical (stall)
AOA. So in stock
condition, they can't be rotated to lift off at anywhere
near stall speed. So,
their minimum speed for takeoff is limited (made higher) by
the length of the
main gear legs. If the same trick is tried with 'short
legs', the pilot would
slam the tailwheel into the ground when he rotates. FWIW,
there are videos of
airliners actually dragging the rear of the fuselage on the
ground when they
over-rotate. Airliners (at least some of them) actually give
up significant
landing speed reduction because they don't want the
weight of long gear legs
when they always have plenty of runway for 'driving it
on' in landing.
In landing mode,
it's just as important. In normal
flying, a pilot would try to '3 point', having the
mains & tailwheel touch
at the same time to land at minimum airspeed. But, since the
wing isn't at
critical AOA in 3 point attitude, he's not really
landing at minimum airspeed.
If the mains were longer, he could land slower. In bush
flying, it gets worse.
Again, watching extreme bush flying, you'll see the
pilot wheel land and keep
the tail off the ground until he's almost stopped. With
a typical taildragger,
he's carrying quite a bit of extra airspeed to
'wheel land' the plane, but he
does it to protect the tailwheel from damage, from rough
ground and from impact
damage of dropping it in. If the legs are extended enough,
he can have full
stall AOA available from the wing, without the tailwheel
being on the ground.
Obviously, this will let him land slower &
shorter.
Does any of that apply
to
Kolbs?
--
Blessed are
the cracked, for they shall let in the light. Groucho
Marx
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
Are there any Kolb people on this list who are qualified mechanical or aero-structure
engineers? I want to ask a question about the tail attachment mechanism.
Before I even mention the question, I want to assure everyone that I AM COMPLETELY
AWARE that there are X thousand Kolbs flying around safely with this stabilizer
attachment. I understand that there have not been many (or perhaps any)
failures of this mechanism. What I am asking about is the theoretical "correctness"
of the design, and whether any other "old-school" airplane people think
that this system is a little wonky.
It took a few moments to finally understand how the mechanism works, and after
looking at everything several times it was clear that there is no direct structural
attachment between the main spar tube of the stabilizer to the fuselage
tube (tailboom). The primary structural load path between the root end of the
main stabilizer spar tube and the fuselage is transmitted through the elevator
hinge... and this hinge isn't even the aircraft style extruded hinge.
So if the air loads try to lift up or push down on the root end of the stabilizer,
it puts all that load through the hinge, into the elevator pivot, and then
finally into the steel ring at the back of the fuselage.
But that's not even the biggest issue in my head. The larger issue is that (according
to plan) the flat hinge is riveted to the tubes along one thin "point of
contact" line tangent to the tube. So the root stabilizer load is all acting
on a hinge, which itself is cantilevered off of one tangent point on the tube.
Now I'm not a degreed engineer, and I'm not a mathematician. So I called a friend
of mine who is a retired aerospace structural engineer, with 50+ years of experience.
I showed him the plans and explained my concern, and I was informed
that my concerns about this system were valid. My Kolb will be built with a more
stable attachment.
My question for any real, degreed, qualified, aircraft-experience engineers is...
has anyone looked at the stabilizer root attachment load path and had these
same concerns?
ONCE AGAIN, this is not an attack on Mr. Kolb or his design, and it is not intended
to cause any panic or concern at this point. What I want to know is why this
load path - through two tangent mounted hinge halves, into a movable elevator,
and then into the fuselage - is good enough, and why it was not appropriate
to install an attachment bracket onto the fuselage at the rear stabilizer spar.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
________________________________________________________________________________
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
The rear attachment of the horizontal stabilizer is NOT through the hinge.
It is through the rear folding weldments that also act as the inner hinge.
When it is set up correctly the hinge line is on the same center as the
swivel bolt in the weldment, however there is some allowance for
misalignment. In that case the weldment in the elevator spar (forward tube
of the elevator), can slide on the bolt in the swivel weldment.
I've seen folding mechanisms on the Kit Fox and repaired the mechanism on
the Highlander and in my HO Homer's is the most clever. All you have to do
to fold the HS on a Kolb is to take out a single bolt that attaches the
lower wires to the rudder post. I'm not sure how you would make it any
simpler.
Rick Girard
On Mon, Mar 21, 2016 at 12:55 PM, Bill Berle
wrote:
>
> Are there any Kolb people on this list who are qualified mechanical or
> aero-structure engineers? I want to ask a question about the tail
> attachment mechanism.
>
> Before I even mention the question, I want to assure everyone that I AM
> COMPLETELY AWARE that there are X thousand Kolbs flying around safely wit
h
> this stabilizer attachment. I understand that there have not been many (o
r
> perhaps any) failures of this mechanism. What I am asking about is the
> theoretical "correctness" of the design, and whether any other "old-schoo
l"
> airplane people think that this system is a little wonky.
>
> It took a few moments to finally understand how the mechanism works, and
> after looking at everything several times it was clear that there is no
> direct structural attachment between the main spar tube of the stabilizer
> to the fuselage tube (tailboom). The primary structural load path between
> the root end of the main stabilizer spar tube and the fuselage is
> transmitted through the elevator hinge... and this hinge isn't even the
> aircraft style extruded hinge.
>
> So if the air loads try to lift up or push down on the root end of the
> stabilizer, it puts all that load through the hinge, into the elevator
> pivot, and then finally into the steel ring at the back of the fuselage.
>
> But that's not even the biggest issue in my head. The larger issue is tha
t
> (according to plan) the flat hinge is riveted to the tubes along one thin
> "point of contact" line tangent to the tube. So the root stabilizer load
is
> all acting on a hinge, which itself is cantilevered off of one tangent
> point on the tube.
>
> Now I'm not a degreed engineer, and I'm not a mathematician. So I called
a
> friend of mine who is a retired aerospace structural engineer, with 50+
> years of experience. I showed him the plans and explained my concern, and
I
> was informed that my concerns about this system were valid. My Kolb will
be
> built with a more stable attachment.
>
> My question for any real, degreed, qualified, aircraft-experience
> engineers is... has anyone looked at the stabilizer root attachment load
> path and had these same concerns?
>
> ONCE AGAIN, this is not an attack on Mr. Kolb or his design, and it is no
t
> intended to cause any panic or concern at this point. What I want to know
> is why this load path - through two tangent mounted hinge halves, into a
> movable elevator, and then into the fuselage - is good enough, and why it
> was not appropriate to install an attachment bracket onto the fuselage at
> the rear stabilizer spar.
>
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and
> for-profit entities
>
>
===========
===========
===========
===========
===========
>
>
--
=9CBlessed are the cracked, for they shall let in the light.=9D
Groucho Marx
<http://www.goodreads.com/author/show/43244.Groucho_Marx>
________________________________________________________________________________
| From: | Eugene Zimmerman <etzimm(at)gmail.com> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
> On Mar 21, 2016, at 1:55 PM, Bill Berle
wrote:
> So I called a friend of mine who is a retired aerospace structural
engineer, with 50+ years of experience.
LOL
The cognitive acuity of anyone with 50+ years of experience should
probably be suspect.
Trust me, I have 50+ years of experience. ;)
________________________________________________________________________________
| From: | Gary Aman <zeprep251(at)aol.com> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
Have to realize Bill,we are talking sub sonic here.A Kolb may not be
what you=99re looking for if you don=99t care what it
weighs.A TBM may be down your ally.I hear they=99re pretty stout
.Good luck finding a kit.
> On Mar 21, 2016, at 6:13 PM, Eugene Zimmerman
wrote:
>
>
>> On Mar 21, 2016, at 1:55 PM, Bill Berle > wrote:
>
>> So I called a friend of mine who is a retired aerospace structural
engineer, with 50+ years of experience.
>
> LOL
>
> The cognitive acuity of anyone with 50+ years of experience should
probably be suspect.
> Trust me, I have 50+ years of experience. ;)
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
I hope I'm wrong, but my review of the plans indicated that there is no traditional
DIRECT structural connection between the rear spar tube and the fuselage
tube. All the load paths have to take a serpentine route and go rearward through
the elevator hinges first, and only then into the U-joint and pivot bolt in
the steel ring. If you removed the elevator hinges (from either the elevator
or the stabilizer), or if you took the pin out of the hinges, you could move the
stabilizer up and down freely while the elevator remained bolted to the fuselage.
Even WITH all the hinges in place, all up and down movement of the stabilizer is
transmitted through the rivets that hold the hinge onto the tubes, and there
is no significant stiffness or bracing against this movement. Essentially you
could move the root end of the stabilizer up and down by hand and this movement
would bend the (un-supported section of) the hinge material. This would attempt
to pry the rivets out of the tube and/or bend the thin metal back and forth.
Also, because of this design the forward stabilizer attach bolt must be a loose
fit, and the stabilizer has to be able to slide back and forth a little.
The only thing that is gained by this unusual structural load path is that 4 ounces
of weight for a pair of fittings (at the rear stabilizer spar) is saved.
Can any one explain to me why this was a good bargain?
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Mon, 3/21/16, Richard Girard wrote:
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
To: "kolb-list(at)matronics.com"
Date: Monday, March 21, 2016, 2:40 PM
The rear attachment
of the horizontal stabilizer is NOT through the hinge. It is
through the rear folding weldments that also act as the
inner hinge. When it is set up correctly the hinge line is
on the same center as the swivel bolt in the weldment,
however there is some allowance for misalignment. In that
case the weldment in the elevator spar (forward tube of the
elevator), can slide on the bolt in the swivel
weldment.I've seen folding mechanisms on the Kit
Fox and repaired the mechanism on the Highlander and in my
HO Homer's is the most clever. All you have to do to
fold the HS on a Kolb is to take out a single bolt that
attaches the lower wires to the rudder post. I'm not
sure how you would make it any simpler.
Rick Girard
On Mon, Mar 21, 2016
at 12:55 PM, Bill Berle
wrote:
Bill Berle
Are there any Kolb people on this list who are qualified
mechanical or aero-structure engineers? I want to ask a
question about the tail attachment mechanism.
Before I even mention the question, I want to assure
everyone that I AM COMPLETELY AWARE that there are X
thousand Kolbs flying around safely with this stabilizer
attachment. I understand that there have not been many (or
perhaps any) failures of this mechanism. What I am asking
about is the theoretical "correctness" of the
design, and whether any other "old-school"
airplane people think that this system is a little wonky.
It took a few moments to finally understand how the
mechanism works, and after looking at everything several
times it was clear that there is no direct structural
attachment between the main spar tube of the stabilizer to
the fuselage tube (tailboom). The primary structural load
path between the root end of the main stabilizer spar tube
and the fuselage is transmitted through the elevator
hinge... and this hinge isn't even the aircraft style
extruded hinge.
So if the air loads try to lift up or push down on the root
end of the stabilizer, it puts all that load through the
hinge, into the elevator pivot, and then finally into the
steel ring at the back of the fuselage.
But that's not even the biggest issue in my head. The
larger issue is that (according to plan) the flat hinge is
riveted to the tubes along one thin "point of
contact" line tangent to the tube. So the root
stabilizer load is all acting on a hinge, which itself is
cantilevered off of one tangent point on the tube.
Now I'm not a degreed engineer, and I'm not a
mathematician. So I called a friend of mine who is a retired
aerospace structural engineer, with 50+ years of experience.
I showed him the plans and explained my concern, and I was
informed that my concerns about this system were valid. My
Kolb will be built with a more stable attachment.
My question for any real, degreed, qualified,
aircraft-experience engineers is... has anyone looked at the
stabilizer root attachment load path and had these same
concerns?
ONCE AGAIN, this is not an attack on Mr. Kolb or his design,
and it is not intended to cause any panic or concern at this
point. What I want to know is why this load path - through
two tangent mounted hinge halves, into a movable elevator,
and then into the fuselage - is good enough, and why it was
not appropriate to install an attachment bracket onto the
fuselage at the rear stabilizer spar.
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and for-profit
entities
==========
br>
fts!)
r>
>
w.buildersbooks.com" rel="noreferrer"
target="_blank">www.buildersbooks.com
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle, List Admin.
==========
-List" rel="noreferrer"
target="_blank">http://www.matronics.com/Navigator?Kolb-List
==========
FORUMS -
eferrer"
target="_blank">http://forums.matronics.com
==========
b Site -
-Matt Dralle, List Admin.
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
==========
--
Blessed
are the cracked, for they shall let in the light. Groucho
Marx
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
Understood, but in this case the person in question is sharp as a tack. It's MY
cognitive acuity that is suspect !
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Mon, 3/21/16, Eugene Zimmerman wrote:
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
To: "Kolb list"
Date: Monday, March 21, 2016, 3:13 PM
On Mar 21,
2016, at 1:55 PM, Bill Berle
wrote:
So I called a friend of mine who is a
retired aerospace structural engineer, with 50+ years of
experience.
LOL
The cognitive acuity of anyone with
50+ years of experience should probably be
suspect.Trust me, I have
50+ years of experience. ;)
________________________________________________________________________________
| From: | "John Hauck" <jhauck(at)elmore.rr.com> |
Rick/Kolbers:
I've been experimenting and flying with heat treated 4130 tubular gear
legs on Kolbs since 1987. Had 36" legs on the original FS. Completely
different main gear on my MKIII, with axles 8" forward and nice nose
high attitude. Yes, they did and do fine full stall landings, get off
the ground quick, and have no nose over problems, even at full throttle
and brakes.
john h
mkIII
Fort Campbell, Kentucky
From: owner-kolb-list-server(at)matronics.com
[mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Richard
Girard
Sent: Monday, March 21, 2016 11:29 AM
Subject: Re: Kolb-List: long legs
Patrick, My Mk III has aluminum legs, my friend's Mk IIIX has steel legs
and lower wing incidence. Neither can get a full stall landing. If I do
I land tail wheel first. Perhaps a full stall landing could be achieved
with longer legs and higher incidence. When I get my Mk III rebuilt
perhaps I'll know.
Rick Girard
On Sat, Mar 19, 2016 at 10:26 AM, Charlie England
wrote:
Since typical AOA is around 14-15 degrees at stall, a 1.5 degree
increase could be close to a 10% increase in 3 point attitude. Not
something to sneeze at.
Again, you must decide if it applies to Kolbs, and whether it actually
matters to you for your style of flying. Who would think that a stock
Super Cub needed shorter field performance, but a lot of bush fliers
obviously consider it inadequate for their purposes.
On Sat, Mar 19, 2016 at 9:40 AM, Patrick Ladd
wrote:
Thanks Charlie,
i can see the reasoning and in fact I saw a guy up in Fairbanks in a
Super Cub pulling the `tail up, full throttle trick`. He powered up,
standing on the brakes, hauled it off the ground by pushing the tail
down and climbing out at just above stall speed.. He did a circuit and
landed again, tail down and hanging on his prop at full chat, like a
helicopter. All in an incredibly short time. I filmed it with a video
camera in one take.
I somehow doubt that many Kolbers have the brakes, to be able to come
close to emulating that performance. Without some actual measurements it
is impossible to calculate accurately the increased AOA available and I
was never any good at trig anyway but assuming 10ft between mains and
tail wheel and an increase in height of the gear legs of say 4 inches,
by how many degrees does that increase the AOA? 1 degree? 1.5 degrees.?
No doubt someone on the list will work it out.
It may well be worth extending legs for other reasons but STOL?.
Questionable.
Pat
From: Charlie England <mailto:ceengland7(at)gmail.com>
Sent: Saturday, March 19, 2016 1:34 PM
Subject: Re: Kolb-List: long legs
On Sat, Mar 19, 2016 at 5:58 AM, Patrick Ladd
wrote:
I may be sticking my neck out here and asking get slapped down but will
someone explain why having longer legs increases the STOL capability of
our a/c. Excepting of course the case where you deliberately hold the
tail down on take off.
I agree with all the advantages which John listed, more wing area
exposed thus slowing landing run etc. However the first thing which
most of us do on take off is to get the tail up into flying position
thus reducing drag and allowing increased acceleration. When the tail is
up the the length of the u/c is irrelevant. In fact having the extra
wing area exposed by having long legs slows the planes acceleration for
exactly the same reason that it shortens the landing run.
When the plane is up on two wheels the AOA is that which was designed
in.
Comments about commercial a/c are largely irrelevant as they are
(mainly) tricycle gear and the wing is in flying position (more or less)
the whole time.
There may be good reasons for making u/c legs longer but I am not
convinced that STOL is one of them except the `keep the skid on the
ground until she drags herself off` scenario which I mentioned..
Enlightenment please.
Pat
I'll take a crack at it, in general terms. You can decide if it applies
to Kolbs.
If you watch videos of hard core bush flying, the pilot will hold the
brakes and raise the tail prior to starting the takeoff roll (to
minimize wing drag, as you point out). When he's got max available
power, he releases the brakes. As soon as he's got minimum flying speed,
he rotates & the plane jumps into the air. Now, most taildraggers sit on
the ground with the wing at a significantly lower angle than critical
(stall) AOA. So in stock condition, they can't be rotated to lift off at
anywhere near stall speed. So, their minimum speed for takeoff is
limited (made higher) by the length of the main gear legs. If the same
trick is tried with 'short legs', the pilot would slam the tailwheel
into the ground when he rotates. FWIW, there are videos of airliners
actually dragging the rear of the fuselage on the ground when they
over-rotate. Airliners (at least some of them) actually give up
significant landing speed reduction because they don't want the weight
of long gear legs when they always have plenty of runway for 'driving it
on' in landing.
In landing mode, it's just as important. In normal flying, a pilot would
try to '3 point', having the mains & tailwheel touch at the same time to
land at minimum airspeed. But, since the wing isn't at critical AOA in 3
point attitude, he's not really landing at minimum airspeed. If the
mains were longer, he could land slower. In bush flying, it gets worse.
Again, watching extreme bush flying, you'll see the pilot wheel land and
keep the tail off the ground until he's almost stopped. With a typical
taildragger, he's carrying quite a bit of extra airspeed to 'wheel land'
the plane, but he does it to protect the tailwheel from damage, from
rough ground and from impact damage of dropping it in. If the legs are
extended enough, he can have full stall AOA available from the wing,
without the tailwheel being on the ground. Obviously, this will let him
land slower & shorter.
Does any of that apply to Kolbs?
--
=9CBlessed are the cracked, for they shall let in the
light.=9D
<http://www.goodreads.com/author/show/43244.Groucho_Marx> Groucho Marx
________________________________________________________________________________
| From: | "John Hauck" <jhauck(at)elmore.rr.com> |
Flying a Kolb with extra long spring steel gear legs is a no brainer. It is easier
to fly and ground handle than the original configuration. With long legs
one does not have to worry about nosing over, as much, which is very easy with
regular length legs. One does not have to be a s**t hot pilot to fly with long
legs.
That all changed when we designed and built the new main gear for my MKIII. By
moving the axles 8" forward we placed about 100 lbs on the tail wheel which is
stuck on the end of a long tail boom. I have to stay on top of and ahead of
my MKIII on the ground. It is a real tail dragger with a lot of pendulum effect.
Took some getting used to initially, but has paid for itself many times
over the last 3300+ hours. Never been on its nose or even given a hint that it
wanted to do such a nasty thing.
On the other hand, a friend with a RANS S7 landed on my 750' strip a couple weeks
ago. Got a little close to the end while turning around to take off. Main
wheel went into a depression and the RANs ate a 1300.00 WARP Drive prop in warp
speed.
To maneuver on wet, rough, soft ground, and high weeds and brush, an aircraft has
to have to ability to keep the tail on the ground when power is applied. A
pusher aircraft does nothing to help prevent this. In fact, it helps you put
you Kolb on its nose. A tractor aircraft is pulling forward and up. Our pushers
are trying to rotate the Kolb around the axles and on its nose.
john h
mkIII
Fort Campbell, KY
-----Original Message-----
From: owner-kolb-list-server(at)matronics.com [mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Bill Berle
Sent: Monday, March 21, 2016 12:20 PM
Subject: Re: Kolb-List: long legs
>From my research, and hearing from other people who have been around Kolbs for
many many years, I think it is safe to say that Homer Kolb designed this series
of aircraft for good handling, good manners, and able to be flown easily by
a low time pilot. By all accounts he succeeded and created a fantastic little
airplane.
But physics do not lie... in order to be a great airplane in one area, design sacrifices
must be made in some other area. This is why a LearJet is not appropriate
for a low time pilot, and this is why a Cessna 172 is (usually) not very
exciting for a high time pilot. I have no doubt that Mr. Kolb understood this,
and chose safety/easy handling over maximum possible performance. The sales
and success of the Kolb fleet has proven him right.
The Kolbs are world renowned for being docile and not demanding. The price paid
for that is that some performance has been sacrificed.
Raising the ground angle high enough so that the airplane can perform a full-stall
3 point landing will clearly allow the airplane to realize the maximum STOL
performance that the wing and engine combination is capable of delivering. That
is basic textbook aeroduynamics. But since the Kolb apparently has good STOL
performance with the stock configuration, it's been a non-issue for the majority
of Kolb pilots.
Speaking ONLY for myself, I would like to maximize the STOL performance of my aircraft,
because I am heavier than an average pilot, and my airplane will not
meet the 254 UL weight either. So rather than having to put a $20K, 100HP engine
on it, I believe I will get 2/3 of the same benefit by having a tall enough
landing gear for the wing to fly sooner. The price I have to pay for that is
that I cannot be a low-time, beginner pilot, and the airplane will be a little
slower (higher drag and drag further underneath the CG).
The modifications that I am planning for my aircraft will not be for everyone.
But I'm hopeful that they will suit my needs.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Mon, 3/21/16, Richard Girard wrote:
Subject: Re: Kolb-List: long legs
To: "kolb-list(at)matronics.com"
Date: Monday, March 21, 2016, 9:29 AM
Patrick,
My Mk III has aluminum legs, my friend's Mk IIIX has steel legs and lower wing
incidence. Neither can get a full stall landing. If I do I land tail wheel
first. Perhaps a full stall landing could be achieved with longer legs and higher
incidence. When I get my Mk III rebuilt perhaps I'll know.
Rick
Girard
On Sat, Mar 19, 2016 at
10:26 AM, Charlie England
wrote:
Since typical AOA is around 14-15 degrees at stall, a 1.5 degree increase could
be close to a 10% increase in 3 point attitude. Not something to sneeze at.
Again, you must decide
if it applies to Kolbs, and whether it actually matters to you for your style
of flying. Who would think that a stock Super Cub needed shorter field performance,
but a lot of bush fliers obviously consider it inadequate for their
purposes.
On Sat, Mar 19, 2016 at
9:40 AM, Patrick Ladd
wrote:
Thanks Charlie,
i can see the reasoning and in fact I saw a guy up in Fairbanks in a Super Cub
pulling the `tail up, full throttle trick`. He powered up, standing on the
brakes, hauled it off the ground by pushing the tail down and climbing out
at just above stall speed.. He did a circuit and landed again, tail down and
hanging on his prop at full chat, like a helicopter. All in an incredibly
short time. I filmed it with a video camera in one take.
I somehow doubt that many Kolbers have the brakes, to be able to come close
to emulating that performance. Without some actual measurements it is impossible
to calculate accurately the increased AOA available and I was never any
good at trig anyway but assuming 10ft between mains and tail wheel and an increase
in height of the gear legs of say 4 inches, by how many degrees does
that increase the AOA? 1 degree? 1.5 degrees.? No doubt someone on the list
will work it out.
It may well be worth extending legs for other reasons but STOL?.
Questionable.
Pat
From: Charlie
England
Sent: Saturday, March 19, 2016 1:34 PM
To: kolb-list(at)matronics.com
Subject: Re: Kolb-List: long
legs
On Sat, Mar 19, 2016
at 5:58 AM, Patrick Ladd
wrote:
I may be sticking my neck out here and asking get slapped down but will
someone explain why having longer legs increases the STOL capability of our
a/c. Excepting of course the case where you deliberately hold the tail down
on
take off.
I agree with all the advantages which John listed, more wing area exposed
thus slowing landing run etc. However the first thing which most of us
do on take off is to get the tail up into flying position thus reducing drag
and allowing increased acceleration. When the tail is up the the length of
the
u/c is irrelevant. In fact having the extra wing area exposed by having long
legs slows the planes acceleration for exactly the same reason that it
shortens the landing run.
When the plane is up on two wheels the AOA is that which was designed
in.
Comments about commercial a/c are largely irrelevant as they are (mainly)
tricycle gear and the wing is in flying position (more or
less) the whole
time.
There may be good reasons for making u/c legs longer but I am not
convinced that STOL is one of them except the `keep the skid on the
ground until she drags herself off` scenario which I mentioned..
Enlightenment please.
Pat
I'll take a crack
at it, in general terms. You can decide if it applies to Kolbs.
If you watch videos of
hard core bush flying, the pilot
will hold the brakes and raise the tail prior to starting the takeoff roll (to
minimize wing drag, as you point out). When he's got max available power,
he releases the brakes. As soon as he's got minimum flying speed, he rotates
& the plane jumps into the air. Now, most taildraggers sit on the ground with
the wing at a significantly lower angle than critical (stall) AOA. So in
stock condition, they can't be rotated to lift off at anywhere near stall speed.
So, their minimum speed for takeoff is limited (made higher) by the length
of the main gear legs. If the same trick is tried with 'short legs', the
pilot would slam the tailwheel into the ground when he rotates. FWIW, there
are videos of airliners actually dragging the rear of the fuselage on the ground
when they over-rotate. Airliners (at least some of them) actually give
up significant landing speed reduction because they don't want the weight of
long gear legs when they always have plenty of runway for 'driving it on'
in landing.
In landing mode,
it's just as important. In normal
flying, a pilot would try to '3 point', having the mains & tailwheel touch at
the same time to land at minimum airspeed. But, since the wing isn't at critical
AOA in 3 point attitude, he's not really landing at minimum airspeed.
If the mains were longer, he could land slower. In bush flying, it gets worse.
Again, watching extreme bush flying, you'll see the pilot wheel land and keep
the tail off the ground until he's almost stopped. With a typical taildragger,
he's carrying quite a bit of extra airspeed to 'wheel land' the plane, but
he does it to protect the tailwheel from damage, from rough ground and from
impact damage of dropping it in. If the legs are extended enough, he can
have full stall AOA available from the wing, without the tailwheel being on
the ground.
Obviously, this will let him land slower & shorter.
Does any of that apply
to
Kolbs?
--
Blessed are
the cracked, for they shall let in the light. Groucho Marx
________________________________________________________________________________
| From: | Dennis Rowe <rowedenny(at)windstream.net> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
Somebody notify John Hauck, as Miss Pfer has around 4000 hours on her airframe
and has taken an eighty horse and two 100 horse Rotax 912 engines well toward
their TBO! The horizontal stabilizer must be ready to fall off at any second.
Maybe I can get a good deal on her since her demise must be imminent.
Bill, just build the dang Firestar to plans and fly it. It won't fall apart.
Dennis "Skid" Rowe
Mk-3 Rotax 690, with a stock Kolb empennage.
> On Mar 21, 2016, at 6:29 PM, Bill Berle wrote:
>
>
> I hope I'm wrong, but my review of the plans indicated that there is no traditional
DIRECT structural connection between the rear spar tube and the fuselage
tube. All the load paths have to take a serpentine route and go rearward through
the elevator hinges first, and only then into the U-joint and pivot bolt
in the steel ring. If you removed the elevator hinges (from either the elevator
or the stabilizer), or if you took the pin out of the hinges, you could move
the stabilizer up and down freely while the elevator remained bolted to the fuselage.
>
> Even WITH all the hinges in place, all up and down movement of the stabilizer
is transmitted through the rivets that hold the hinge onto the tubes, and there
is no significant stiffness or bracing against this movement. Essentially you
could move the root end of the stabilizer up and down by hand and this movement
would bend the (un-supported section of) the hinge material. This would attempt
to pry the rivets out of the tube and/or bend the thin metal back and forth.
>
> Also, because of this design the forward stabilizer attach bolt must be a loose
fit, and the stabilizer has to be able to slide back and forth a little.
>
> The only thing that is gained by this unusual structural load path is that 4
ounces of weight for a pair of fittings (at the rear stabilizer spar) is saved.
Can any one explain to me why this was a good bargain?
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and for-profit entities
>
> --------------------------------------------
> On Mon, 3/21/16, Richard Girard wrote:
>
> Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
> To: "kolb-list(at)matronics.com"
> Date: Monday, March 21, 2016, 2:40 PM
>
> The rear attachment
> of the horizontal stabilizer is NOT through the hinge. It is
> through the rear folding weldments that also act as the
> inner hinge. When it is set up correctly the hinge line is
> on the same center as the swivel bolt in the weldment,
> however there is some allowance for misalignment. In that
> case the weldment in the elevator spar (forward tube of the
> elevator), can slide on the bolt in the swivel
> weldment.I've seen folding mechanisms on the Kit
> Fox and repaired the mechanism on the Highlander and in my
> HO Homer's is the most clever. All you have to do to
> fold the HS on a Kolb is to take out a single bolt that
> attaches the lower wires to the rudder post. I'm not
> sure how you would make it any simpler.
> Rick Girard
> On Mon, Mar 21, 2016
> at 12:55 PM, Bill Berle
> wrote:
> Bill Berle
>
>
>
> Are there any Kolb people on this list who are qualified
> mechanical or aero-structure engineers? I want to ask a
> question about the tail attachment mechanism.
>
>
>
> Before I even mention the question, I want to assure
> everyone that I AM COMPLETELY AWARE that there are X
> thousand Kolbs flying around safely with this stabilizer
> attachment. I understand that there have not been many (or
> perhaps any) failures of this mechanism. What I am asking
> about is the theoretical "correctness" of the
> design, and whether any other "old-school"
> airplane people think that this system is a little wonky.
>
>
>
> It took a few moments to finally understand how the
> mechanism works, and after looking at everything several
> times it was clear that there is no direct structural
> attachment between the main spar tube of the stabilizer to
> the fuselage tube (tailboom). The primary structural load
> path between the root end of the main stabilizer spar tube
> and the fuselage is transmitted through the elevator
> hinge... and this hinge isn't even the aircraft style
> extruded hinge.
>
>
>
> So if the air loads try to lift up or push down on the root
> end of the stabilizer, it puts all that load through the
> hinge, into the elevator pivot, and then finally into the
> steel ring at the back of the fuselage.
>
>
>
> But that's not even the biggest issue in my head. The
> larger issue is that (according to plan) the flat hinge is
> riveted to the tubes along one thin "point of
> contact" line tangent to the tube. So the root
> stabilizer load is all acting on a hinge, which itself is
> cantilevered off of one tangent point on the tube.
>
>
>
> Now I'm not a degreed engineer, and I'm not a
> mathematician. So I called a friend of mine who is a retired
> aerospace structural engineer, with 50+ years of experience.
> I showed him the plans and explained my concern, and I was
> informed that my concerns about this system were valid. My
> Kolb will be built with a more stable attachment.
>
>
>
> My question for any real, degreed, qualified,
> aircraft-experience engineers is... has anyone looked at the
> stabilizer root attachment load path and had these same
> concerns?
>
>
>
> ONCE AGAIN, this is not an attack on Mr. Kolb or his design,
> and it is not intended to cause any panic or concern at this
> point. What I want to know is why this load path - through
> two tangent mounted hinge halves, into a movable elevator,
> and then into the fuselage - is good enough, and why it was
> not appropriate to install an attachment bracket onto the
> fuselage at the rear stabilizer spar.
>
>
>
>
>
> Bill Berle
>
> www.ezflaphandle.com
> - safety & performance upgrade for light aircraft
>
> www.grantstar.net
> - winning proposals for non-profit and for-profit
> entities
>
>
>
>
>
> ==========
>
> br>
> fts!)
>
> r>
>>
> w.buildersbooks.com" rel="noreferrer"
> target="_blank">www.buildersbooks.com
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
>
> -Matt Dralle, List Admin.
>
> ==========
>
> -List" rel="noreferrer"
> target="_blank">http://www.matronics.com/Navigator?Kolb-List
>
> ==========
>
> FORUMS -
>
> eferrer"
> target="_blank">http://forums.matronics.com
>
> ==========
>
> b Site -
>
> -Matt Dralle, List Admin.
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
>
> ==========
>
>
>
>
>
>
>
>
>
>
> --
> Blessed
> are the cracked, for they shall let in the light. Groucho
> Marx
>
>
>
>
>
>
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
I wish I could have placed a bet in Las Vegas as to how quickly some of the people
would jump in and say that these airplanes have X number of hours and Y number
of landings without failure. I would have been able to buy another Kolb :)
With all due respect to everyone, I KNOW that these airplanes are not falling out
of the sky.
Now, also with all due respect, can someone with engineering knowledge tell me,
ON A TECHNICAL ENGINEERING level, how it could EVER be considered as good design
practice to essentially cantilever a piano hinge off of a thin wall round
tube, with one line of rivets at the tangent contact point, and with flight loads
often perpendicular to that axis, where that cantilever loaded hinge is not
only connecting two pieces of primary aircraft structure but also attaching
a primary control surface ?
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Tue, 3/22/16, Dennis Rowe wrote:
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
To: kolb-list(at)matronics.com
Date: Tuesday, March 22, 2016, 9:59 AM
Dennis Rowe
Somebody notify John Hauck, as Miss Pfer has around 4000
hours on her airframe and has taken an eighty horse and two
100 horse Rotax 912 engines well toward their TBO! The
horizontal stabilizer must be ready to fall off at any
second.
Maybe I can get a good deal on her since her demise must be
imminent.
Bill, just build the dang Firestar to plans and fly it. It
won't fall apart.
Dennis "Skid" Rowe
Mk-3 Rotax 690, with a stock Kolb empennage.
> On Mar 21, 2016, at 6:29 PM, Bill Berle
wrote:
>
>
> I hope I'm wrong, but my review of the plans indicated
that there is no traditional DIRECT structural connection
between the rear spar tube and the fuselage tube. All the
load paths have to take a serpentine route and go rearward
through the elevator hinges first, and only then into the
U-joint and pivot bolt in the steel ring. If you removed the
elevator hinges (from either the elevator or the
stabilizer), or if you took the pin out of the hinges, you
could move the stabilizer up and down freely while the
elevator remained bolted to the fuselage.
>
> Even WITH all the hinges in place, all up and down
movement of the stabilizer is transmitted through the rivets
that hold the hinge onto the tubes, and there is no
significant stiffness or bracing against this movement.
Essentially you could move the root end of the stabilizer up
and down by hand and this movement would bend the
(un-supported section of) the hinge material. This would
attempt to pry the rivets out of the tube and/or bend the
thin metal back and forth.
>
> Also, because of this design the forward stabilizer
attach bolt must be a loose fit, and the stabilizer has to
be able to slide back and forth a little.
>
> The only thing that is gained by this unusual
structural load path is that 4 ounces of weight for a pair
of fittings (at the rear stabilizer spar) is saved. Can any
one explain to me why this was a good bargain?
>
> Bill Berle
> www.ezflaphandle.com - safety & performance
upgrade for light aircraft
> www.grantstar.net
- winning proposals for non-profit and
for-profit entities
>
> --------------------------------------------
> On Mon, 3/21/16, Richard Girard
wrote:
>
> Subject: Re: Kolb-List: Elevator/Stabilizer hinge
ass'y
> To: "kolb-list(at)matronics.com"
> Date: Monday, March 21, 2016, 2:40 PM
>
> The rear attachment
> of the horizontal stabilizer is NOT through the hinge.
It is
> through the rear folding weldments that also act as
the
> inner hinge. When it is set up correctly the hinge line
is
> on the same center as the swivel bolt in the weldment,
> however there is some allowance for misalignment. In
that
> case the weldment in the elevator spar (forward tube of
the
> elevator), can slide on the bolt in the swivel
> weldment.I've seen folding mechanisms on the Kit
> Fox and repaired the mechanism on the Highlander and in
my
> HO Homer's is the most clever. All you have to do to
> fold the HS on a Kolb is to take out a single bolt
that
> attaches the lower wires to the rudder post. I'm not
> sure how you would make it any simpler.
> Rick Girard
> On Mon, Mar 21, 2016
> at 12:55 PM, Bill Berle
> wrote:
> Bill Berle
>
>
>
> Are there any Kolb people on this list who are
qualified
> mechanical or aero-structure engineers? I want to ask
a
> question about the tail attachment mechanism.
>
>
>
> Before I even mention the question, I want to assure
> everyone that I AM COMPLETELY AWARE that there are X
> thousand Kolbs flying around safely with this
stabilizer
> attachment. I understand that there have not been many
(or
> perhaps any) failures of this mechanism. What I am
asking
> about is the theoretical "correctness" of the
> design, and whether any other "old-school"
> airplane people think that this system is a little
wonky.
>
>
>
> It took a few moments to finally understand how the
> mechanism works, and after looking at everything
several
> times it was clear that there is no direct structural
> attachment between the main spar tube of the stabilizer
to
> the fuselage tube (tailboom). The primary structural
load
> path between the root end of the main stabilizer spar
tube
> and the fuselage is transmitted through the elevator
> hinge... and this hinge isn't even the aircraft style
> extruded hinge.
>
>
>
> So if the air loads try to lift up or push down on the
root
> end of the stabilizer, it puts all that load through
the
> hinge, into the elevator pivot, and then finally into
the
> steel ring at the back of the fuselage.
>
>
>
> But that's not even the biggest issue in my head. The
> larger issue is that (according to plan) the flat hinge
is
> riveted to the tubes along one thin "point of
> contact" line tangent to the tube. So the root
> stabilizer load is all acting on a hinge, which itself
is
> cantilevered off of one tangent point on the
tube.
>
>
>
> Now I'm not a degreed engineer, and I'm not a
> mathematician. So I called a friend of mine who is a
retired
> aerospace structural engineer, with 50+ years of
experience.
> I showed him the plans and explained my concern, and I
was
> informed that my concerns about this system were valid.
My
> Kolb will be built with a more stable attachment.
>
>
>
> My question for any real, degreed, qualified,
> aircraft-experience engineers is... has anyone looked
at the
> stabilizer root attachment load path and had these
same
> concerns?
>
>
>
> ONCE AGAIN, this is not an attack on Mr. Kolb or his
design,
> and it is not intended to cause any panic or concern at
this
> point. What I want to know is why this load path -
through
> two tangent mounted hinge halves, into a movable
elevator,
> and then into the fuselage - is good enough, and why it
was
> not appropriate to install an attachment bracket onto
the
> fuselage at the rear stabilizer spar.
>
>
>
>
>
> Bill Berle
>
> www.ezflaphandle.com
> - safety & performance upgrade for light aircraft
>
> www.grantstar.net
> - winning proposals for
non-profit and for-profit
> entities
>
>
>
>
>
> ==========
>
> br>
> fts!)
>
> r>
>>
> w.buildersbooks.com" rel="noreferrer"
> target="_blank">www.buildersbooks.com
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
>
> -Matt
Dralle, List Admin.
>
> ==========
>
> -List" rel="noreferrer"
> target="_blank">http://www.matronics.com/Navigator?Kolb-List
>
> ==========
>
> FORUMS -
>
> eferrer"
> target="_blank">http://forums.matronics.com
>
> ==========
>
> b Site -
>
> -Matt
Dralle, List Admin.
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
>
> ==========
>
>
>
>
>
>
>
>
>
>
> --
> Blessed
> are the cracked, for they shall let in the
light.Groucho
> Marx
>
>
>
>
>
>
Lists This Month --
Some AWESOME FREE Gifts!)
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Dralle, List Admin.
________________________________________________________________________________
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
| From: | Charlie England <ceengland7(at)gmail.com> |
Any way to post a pic of the assembly, or the construction drawing, for
those of us who don't have that model to inspect? Not the entire set of
plans, of course; just the area in question.
On 3/22/2016 12:39 PM, Bill Berle wrote:
>
> I wish I could have placed a bet in Las Vegas as to how quickly some of the people
would jump in and say that these airplanes have X number of hours and Y
number of landings without failure. I would have been able to buy another Kolb
:)
>
> With all due respect to everyone, I KNOW that these airplanes are not falling
out of the sky.
>
> Now, also with all due respect, can someone with engineering knowledge tell me,
ON A TECHNICAL ENGINEERING level, how it could EVER be considered as good design
practice to essentially cantilever a piano hinge off of a thin wall round
tube, with one line of rivets at the tangent contact point, and with flight
loads often perpendicular to that axis, where that cantilever loaded hinge is
not only connecting two pieces of primary aircraft structure but also attaching
a primary control surface ?
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and for-profit entities
>
> --------------------------------------------
> On Tue, 3/22/16, Dennis Rowe wrote:
>
> Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
> To: kolb-list(at)matronics.com
> Date: Tuesday, March 22, 2016, 9:59 AM
>
> Dennis Rowe
>
> Somebody notify John Hauck, as Miss Pfer has around 4000
> hours on her airframe and has taken an eighty horse and two
> 100 horse Rotax 912 engines well toward their TBO! The
> horizontal stabilizer must be ready to fall off at any
> second.
> Maybe I can get a good deal on her since her demise must be
> imminent.
> Bill, just build the dang Firestar to plans and fly it. It
> won't fall apart.
>
>
> Dennis "Skid" Rowe
> Mk-3 Rotax 690, with a stock Kolb empennage.
>
>
>
> > On Mar 21, 2016, at 6:29 PM, Bill Berle
> wrote:
> >
> >
> > I hope I'm wrong, but my review of the plans indicated
> that there is no traditional DIRECT structural connection
> between the rear spar tube and the fuselage tube. All the
> load paths have to take a serpentine route and go rearward
> through the elevator hinges first, and only then into the
> U-joint and pivot bolt in the steel ring. If you removed the
> elevator hinges (from either the elevator or the
> stabilizer), or if you took the pin out of the hinges, you
> could move the stabilizer up and down freely while the
> elevator remained bolted to the fuselage.
> >
> > Even WITH all the hinges in place, all up and down
> movement of the stabilizer is transmitted through the rivets
> that hold the hinge onto the tubes, and there is no
> significant stiffness or bracing against this movement.
> Essentially you could move the root end of the stabilizer up
> and down by hand and this movement would bend the
> (un-supported section of) the hinge material. This would
> attempt to pry the rivets out of the tube and/or bend the
> thin metal back and forth.
> >
> > Also, because of this design the forward stabilizer
> attach bolt must be a loose fit, and the stabilizer has to
> be able to slide back and forth a little.
> >
> > The only thing that is gained by this unusual
> structural load path is that 4 ounces of weight for a pair
> of fittings (at the rear stabilizer spar) is saved. Can any
> one explain to me why this was a good bargain?
> >
> > Bill Berle
> > www.ezflaphandle.com - safety & performance
> upgrade for light aircraft
> > www.grantstar.net
> - winning proposals for non-profit and
> for-profit entities
> >
> > --------------------------------------------
> > On Mon, 3/21/16, Richard Girard
> wrote:
> >
> > Subject: Re: Kolb-List: Elevator/Stabilizer hinge
> ass'y
> > To: "kolb-list(at)matronics.com"
>
> > Date: Monday, March 21, 2016, 2:40 PM
> >
> > The rear attachment
> > of the horizontal stabilizer is NOT through the hinge.
> It is
> > through the rear folding weldments that also act as
> the
> > inner hinge. When it is set up correctly the hinge line
> is
> > on the same center as the swivel bolt in the weldment,
> > however there is some allowance for misalignment. In
> that
> > case the weldment in the elevator spar (forward tube of
> the
> > elevator), can slide on the bolt in the swivel
> > weldment.I've seen folding mechanisms on the Kit
> > Fox and repaired the mechanism on the Highlander and in
> my
> > HO Homer's is the most clever. All you have to do to
> > fold the HS on a Kolb is to take out a single bolt
> that
> > attaches the lower wires to the rudder post. I'm not
> > sure how you would make it any simpler.
> > Rick Girard
> > On Mon, Mar 21, 2016
> > at 12:55 PM, Bill Berle
> > wrote:
> > Bill Berle
> >
> >
> >
> > Are there any Kolb people on this list who are
> qualified
> > mechanical or aero-structure engineers? I want to ask
> a
> > question about the tail attachment mechanism.
> >
> >
> >
> > Before I even mention the question, I want to assure
> > everyone that I AM COMPLETELY AWARE that there are X
> > thousand Kolbs flying around safely with this
> stabilizer
> > attachment. I understand that there have not been many
> (or
> > perhaps any) failures of this mechanism. What I am
> asking
> > about is the theoretical "correctness" of the
> > design, and whether any other "old-school"
> > airplane people think that this system is a little
> wonky.
> >
> >
> >
> > It took a few moments to finally understand how the
> > mechanism works, and after looking at everything
> several
> > times it was clear that there is no direct structural
> > attachment between the main spar tube of the stabilizer
> to
> > the fuselage tube (tailboom). The primary structural
> load
> > path between the root end of the main stabilizer spar
> tube
> > and the fuselage is transmitted through the elevator
> > hinge... and this hinge isn't even the aircraft style
> > extruded hinge.
> >
> >
> >
> > So if the air loads try to lift up or push down on the
> root
> > end of the stabilizer, it puts all that load through
> the
> > hinge, into the elevator pivot, and then finally into
> the
> > steel ring at the back of the fuselage.
> >
> >
> >
> > But that's not even the biggest issue in my head. The
> > larger issue is that (according to plan) the flat hinge
> is
> > riveted to the tubes along one thin "point of
> > contact" line tangent to the tube. So the root
> > stabilizer load is all acting on a hinge, which itself
> is
> > cantilevered off of one tangent point on the
> tube.
> >
> >
> >
> > Now I'm not a degreed engineer, and I'm not a
> > mathematician. So I called a friend of mine who is a
> retired
> > aerospace structural engineer, with 50+ years of
> experience.
> > I showed him the plans and explained my concern, and I
> was
> > informed that my concerns about this system were valid.
> My
> > Kolb will be built with a more stable attachment.
> >
> >
> >
> > My question for any real, degreed, qualified,
> > aircraft-experience engineers is... has anyone looked
> at the
> > stabilizer root attachment load path and had these
> same
> > concerns?
> >
> >
> >
> > ONCE AGAIN, this is not an attack on Mr. Kolb or his
> design,
> > and it is not intended to cause any panic or concern at
> this
> > point. What I want to know is why this load path -
> through
> > two tangent mounted hinge halves, into a movable
> elevator,
> > and then into the fuselage - is good enough, and why it
> was
> > not appropriate to install an attachment bracket onto
> the
> > fuselage at the rear stabilizer spar.
> >
> >
> >
> >
> >
> > Bill Berle
> >
________________________________________________________________________________
| From: | "Stuart Harner" <stuart(at)harnerfarm.net> |
| Subject: | Elevator/Stabilizer hinge ass'y |
Bill,
I am not an engineer but I did stay in a Holiday Inn last night. :) No, not really,
but I do have a fundamental understanding of load transmission through a
structure.
First a question, and please don't be offended. Have you had an opportunity to
observe the structure of the Kolb tail while it was being folded and then again
when it is bolted into place? I asked this because I found a couple of things
in the plans of the Firefly that I did not understand until I was able to
actually see it live. Simply put, I had trouble visualizing it from just the plans.
One thing that I think is missing from this discussion is the loads carried by
the brace wires. I would posit that most of the forces from the tail that are
transmitted to the boom tube are carried by the braces. These, when properly tensioned
are actually pre-loaded slightly. This puts the tubes in compression
which makes the whole thing quite strong. It also transfers the loads from the
horizontals to the steel post of the verticals which in turn is transferred to
the boom tube via the steel ring which is bolted and/or riveted to the tube.
Of course some loads are transferred through the hinge points and the front hinge
must be able to slide slightly as the elevator moves through its arc of travel.
Could this be made stronger? Of course, but not without sacrificing something
else such as weight or foldability. It is actually a very clever design and
I suspect that the majority of loads that move through the rear hinge come
from the elevator and not the stabilizer.
I would also bet that the loads carried through the hinges is far below the shear
and tension limits of properly installed rivets.
I am actually more "freaked out" by the fact that everything in the tail depends
on that one little 3/16" bolt (Firefly) that holds the lower braces in place.
Really, the threads on that bolt are all there is between you and falling out
of the sky. To combat this irrationality I swap out the bolt fairly often and
the nuts even more often. If it really bothered me, I would stay on the ground.
:)
Perhaps you could send a copy of your plans to Barnaby Wainfan and ask for his
analysis. I hear he is a really nice guy. From reading his articles over the years
I am sure he could provide the answers you seek.
As Uncle Red used to say: "Remember, if women don't find you handsome, they should
at least find you handy"
Stuart
-----Original Message-----
From: owner-kolb-list-server(at)matronics.com [mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Bill Berle
Sent: Monday, March 21, 2016 5:30 PM
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
I hope I'm wrong, but my review of the plans indicated that there is no traditional
DIRECT structural connection between the rear spar tube and the fuselage
tube. All the load paths have to take a serpentine route and go rearward through
the elevator hinges first, and only then into the U-joint and pivot bolt in
the steel ring. If you removed the elevator hinges (from either the elevator
or the stabilizer), or if you took the pin out of the hinges, you could move the
stabilizer up and down freely while the elevator remained bolted to the fuselage.
Even WITH all the hinges in place, all up and down movement of the stabilizer is
transmitted through the rivets that hold the hinge onto the tubes, and there
is no significant stiffness or bracing against this movement. Essentially you
could move the root end of the stabilizer up and down by hand and this movement
would bend the (un-supported section of) the hinge material. This would attempt
to pry the rivets out of the tube and/or bend the thin metal back and forth.
Also, because of this design the forward stabilizer attach bolt must be a loose
fit, and the stabilizer has to be able to slide back and forth a little.
The only thing that is gained by this unusual structural load path is that 4 ounces
of weight for a pair of fittings (at the rear stabilizer spar) is saved.
Can any one explain to me why this was a good bargain?
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Mon, 3/21/16, Richard Girard wrote:
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
To: "kolb-list(at)matronics.com"
Date: Monday, March 21, 2016, 2:40 PM
The rear attachment
of the horizontal stabilizer is NOT through the hinge. It is through the rear
folding weldments that also act as the inner hinge. When it is set up correctly
the hinge line is on the same center as the swivel bolt in the weldment,
however there is some allowance for misalignment. In that case the weldment
in the elevator spar (forward tube of the elevator), can slide on the bolt in
the swivel weldment.I've seen folding mechanisms on the Kit Fox and repaired
the mechanism on the Highlander and in my HO Homer's is the most clever. All
you have to do to fold the HS on a Kolb is to take out a single bolt that
attaches the lower wires to the rudder post. I'm not sure how you would make
it any simpler.
Rick Girard
On Mon, Mar 21, 2016
at 12:55 PM, Bill Berle
wrote:
Bill Berle
Are there any Kolb people on this list who are qualified mechanical or aero-structure
engineers? I want to ask a question about the tail attachment mechanism.
Before I even mention the question, I want to assure everyone that I AM COMPLETELY
AWARE that there are X thousand Kolbs flying around safely with this stabilizer
attachment. I understand that there have not been many (or perhaps
any) failures of this mechanism. What I am asking about is the theoretical "correctness"
of the design, and whether any other "old-school"
airplane people think that this system is a little wonky.
It took a few moments to finally understand how the mechanism works, and after
looking at everything several times it was clear that there is no direct structural
attachment between the main spar tube of the stabilizer to the fuselage
tube (tailboom). The primary structural load path between the root end of
the main stabilizer spar tube and the fuselage is transmitted through the elevator
hinge... and this hinge isn't even the aircraft style extruded hinge.
So if the air loads try to lift up or push down on the root end of the stabilizer,
it puts all that load through the hinge, into the elevator pivot, and then
finally into the steel ring at the back of the fuselage.
But that's not even the biggest issue in my head. The larger issue is that (according
to plan) the flat hinge is riveted to the tubes along one thin "point
of contact" line tangent to the tube. So the root stabilizer load is all acting
on a hinge, which itself is cantilevered off of one tangent point on the
tube.
Now I'm not a degreed engineer, and I'm not a mathematician. So I called a friend
of mine who is a retired aerospace structural engineer, with 50+ years of
experience.
I showed him the plans and explained my concern, and I was informed that my concerns
about this system were valid. My Kolb will be built with a more stable
attachment.
My question for any real, degreed, qualified, aircraft-experience engineers is...
has anyone looked at the stabilizer root attachment load path and had these
same concerns?
ONCE AGAIN, this is not an attack on Mr. Kolb or his design, and it is not intended
to cause any panic or concern at this point. What I want to know is why
this load path - through two tangent mounted hinge halves, into a movable elevator,
and then into the fuselage - is good enough, and why it was not appropriate
to install an attachment bracket onto the fuselage at the rear stabilizer
spar.
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and for-profit entities
==========
br>
fts!)
r>
>
w.buildersbooks.com" rel="noreferrer"
target="_blank">www.buildersbooks.com
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
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==========
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eferrer"
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rel="noreferrer"
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==========
--
Blessed
are the cracked, for they shall let in the light. Groucho Marx
________________________________________________________________________________
| From: | "Bob" <rmurrill(at)cox.net> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
I suffer from the same 50 year malady you mentioned earlier, but would
suggest you propose to your aero/ structures engineer
friend a couple of alternate details. I would agree that the structural
configuration is non standard, with the appearance of some odd geometric
coupling, but it has clearly worked well for many years and tens of
thousands of hours fleet time regardless of the Las Vegas odd makers.
The main point is the loads are very small compared to the strength of the
hardware...arguably by more than an order of magnitude.
Flying downloads on the horizontal tail are probably in the
50 lb maybe 100 lb at the most to provide flyable static pitch and speed
stability. Low aspect ratio and taper puts the center of pressure fairly
close to the wire bracing attachments, probably forward and inboard, so most
of these downloads are taken out as tension in those wires and compression
in the vertical stabilizer tube. Smaller loads are reacted at the root
bolts and across the hinges. One would not attempt to design the structure
for full elevator deflection at
Vne, so reasonably one would only ever see relatively modest changes in the
aero down loads throughout the flight spectrum. A fairly extreme case that
would develop very high pitch rates and require elevator correction would be
full power to idle or the reverse. That would produce about 300 lb of force
at maybe 2 ft
above the cg and would require a change in tail download of about
40 lb assuming the moment arm is about 15 ft. So thats 20 lb per side.
Each of the hinge rivets assuming they are 1/8th inch is good for 120 lbs
single shear. The load is shared by lots of rivets. The bolts are I
believe 5/16 which are good for 5,500 lb single shear even if only grade 5.
I would argue that the hinges, dozens of rivets and large diameter pivoting
bolts appear
to be overdesigned for the basic small aero loads of this aircraft. Fatigue
loads from the prop wash swirl could be an issue,
but apparently not from fleet experience.
Ultimate static strength is most likely dictated by the aluminum tubing
substructure, not by the rivets, hinges, or support bolts....
I recommend not trying to improve the design!
Bob
-----Original Message-----
From: Bill Berle
Sent: Tuesday, March 22, 2016 10:39 AM
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
I wish I could have placed a bet in Las Vegas as to how quickly some of the
people would jump in and say that these airplanes have X number of hours and
Y number of landings without failure. I would have been able to buy another
Kolb :)
With all due respect to everyone, I KNOW that these airplanes are not
falling out of the sky.
Now, also with all due respect, can someone with engineering knowledge tell
me, ON A TECHNICAL ENGINEERING level, how it could EVER be considered as
good design practice to essentially cantilever a piano hinge off of a thin
wall round tube, with one line of rivets at the tangent contact point, and
with flight loads often perpendicular to that axis, where that cantilever
loaded hinge is not only connecting two pieces of primary aircraft structure
but also attaching a primary control surface ?
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and
for-profit entities
--------------------------------------------
On Tue, 3/22/16, Dennis Rowe wrote:
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
Date: Tuesday, March 22, 2016, 9:59 AM
Dennis Rowe
Somebody notify John Hauck, as Miss Pfer has around 4000
hours on her airframe and has taken an eighty horse and two
100 horse Rotax 912 engines well toward their TBO! The
horizontal stabilizer must be ready to fall off at any
second.
Maybe I can get a good deal on her since her demise must be
imminent.
Bill, just build the dang Firestar to plans and fly it. It
won't fall apart.
Dennis "Skid" Rowe
Mk-3 Rotax 690, with a stock Kolb empennage.
> On Mar 21, 2016, at 6:29 PM, Bill Berle
wrote:
>
>
> I hope I'm wrong, but my review of the plans indicated
that there is no traditional DIRECT structural connection
between the rear spar tube and the fuselage tube. All the
load paths have to take a serpentine route and go rearward
through the elevator hinges first, and only then into the
U-joint and pivot bolt in the steel ring. If you removed the
elevator hinges (from either the elevator or the
stabilizer), or if you took the pin out of the hinges, you
could move the stabilizer up and down freely while the
elevator remained bolted to the fuselage.
>
> Even WITH all the hinges in place, all up and down
movement of the stabilizer is transmitted through the rivets
that hold the hinge onto the tubes, and there is no
significant stiffness or bracing against this movement.
Essentially you could move the root end of the stabilizer up
and down by hand and this movement would bend the
(un-supported section of) the hinge material. This would
attempt to pry the rivets out of the tube and/or bend the
thin metal back and forth.
>
> Also, because of this design the forward stabilizer
attach bolt must be a loose fit, and the stabilizer has to
be able to slide back and forth a little.
>
> The only thing that is gained by this unusual
structural load path is that 4 ounces of weight for a pair
of fittings (at the rear stabilizer spar) is saved. Can any
one explain to me why this was a good bargain?
>
> Bill Berle
> www.ezflaphandle.com - safety & performance
upgrade for light aircraft
> www.grantstar.net
- winning proposals for non-profit and
for-profit entities
>
> --------------------------------------------
> On Mon, 3/21/16, Richard Girard
wrote:
>
> Subject: Re: Kolb-List: Elevator/Stabilizer hinge
ass'y
> To: "kolb-list(at)matronics.com"
> Date: Monday, March 21, 2016, 2:40 PM
>
> The rear attachment
> of the horizontal stabilizer is NOT through the hinge.
It is
> through the rear folding weldments that also act as
the
> inner hinge. When it is set up correctly the hinge line
is
> on the same center as the swivel bolt in the weldment,
> however there is some allowance for misalignment. In
that
> case the weldment in the elevator spar (forward tube of
the
> elevator), can slide on the bolt in the swivel
> weldment.I've seen folding mechanisms on the Kit
> Fox and repaired the mechanism on the Highlander and in
my
> HO Homer's is the most clever. All you have to do to
> fold the HS on a Kolb is to take out a single bolt
that
> attaches the lower wires to the rudder post. I'm not
> sure how you would make it any simpler.
> Rick Girard
> On Mon, Mar 21, 2016
> at 12:55 PM, Bill Berle
> wrote:
> Bill Berle
>
>
> Are there any Kolb people on this list who are
qualified
> mechanical or aero-structure engineers? I want to ask
a
> question about the tail attachment mechanism.
>
>
> Before I even mention the question, I want to assure
> everyone that I AM COMPLETELY AWARE that there are X
> thousand Kolbs flying around safely with this
stabilizer
> attachment. I understand that there have not been many
(or
> perhaps any) failures of this mechanism. What I am
asking
> about is the theoretical "correctness" of the
> design, and whether any other "old-school"
> airplane people think that this system is a little
wonky.
>
>
> It took a few moments to finally understand how the
> mechanism works, and after looking at everything
several
> times it was clear that there is no direct structural
> attachment between the main spar tube of the stabilizer
to
> the fuselage tube (tailboom). The primary structural
load
> path between the root end of the main stabilizer spar
tube
> and the fuselage is transmitted through the elevator
> hinge... and this hinge isn't even the aircraft style
> extruded hinge.
>
>
> So if the air loads try to lift up or push down on the
root
> end of the stabilizer, it puts all that load through
the
> hinge, into the elevator pivot, and then finally into
the
> steel ring at the back of the fuselage.
>
>
> But that's not even the biggest issue in my head. The
> larger issue is that (according to plan) the flat hinge
is
> riveted to the tubes along one thin "point of
> contact" line tangent to the tube. So the root
> stabilizer load is all acting on a hinge, which itself
is
> cantilevered off of one tangent point on the
tube.
>
>
> Now I'm not a degreed engineer, and I'm not a
> mathematician. So I called a friend of mine who is a
retired
> aerospace structural engineer, with 50+ years of
experience.
> I showed him the plans and explained my concern, and I
was
> informed that my concerns about this system were valid.
My
> Kolb will be built with a more stable attachment.
>
>
> My question for any real, degreed, qualified,
> aircraft-experience engineers is... has anyone looked
at the
> stabilizer root attachment load path and had these
same
> concerns?
>
>
> ONCE AGAIN, this is not an attack on Mr. Kolb or his
design,
> and it is not intended to cause any panic or concern at
this
> point. What I want to know is why this load path -
through
> two tangent mounted hinge halves, into a movable
elevator,
> and then into the fuselage - is good enough, and why it
was
> not appropriate to install an attachment bracket onto
the
> fuselage at the rear stabilizer spar.
>
>
> Bill Berle
>
> www.ezflaphandle.com
> - safety & performance upgrade for light aircraft
>
> www.grantstar.net
> - winning proposals for
non-profit and for-profit
> entities
>
>
> ==========
>
> br>
> fts!)
>
> r>
>>
> w.buildersbooks.com" rel="noreferrer"
> target="_blank">www.buildersbooks.com
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
>
> -Matt
Dralle, List Admin.
>
> ==========
>
> -List" rel="noreferrer"
> target="_blank">http://www.matronics.com/Navigator?Kolb-List
>
> ==========
>
> FORUMS -
>
> eferrer"
> target="_blank">http://forums.matronics.com
>
> ==========
>
> b Site -
>
> -Matt
Dralle, List Admin.
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
>
> ==========
>
>
> --
> Blessed
> are the cracked, for they shall let in the
light. Groucho
> Marx
>
>
Lists This Month --
Some AWESOME FREE Gifts!)
Raiser. Click on
more about
Gifts provided
www.buildersbooks.com
-Matt
Dralle, List Admin.
Forum -
- MATRONICS WEB FORUMS -
List Contribution Web Site -
-Matt
Dralle, List Admin.
________________________________________________________________________________
| From: | Jim Baker <jimbaker(at)npacc.net> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
Now the onus is on you. Post one single incident of horizontal stab/elevator failure.
Just one.
On the other hand, they are experimental and you, the builder, are the experimenter.
Press on. Could care less.
Jim Baker
405 426 5377
-----Original Message-----
From: Bill Berle <victorbravo(at)sbcglobal.net>
Sent: Tue, 22 Mar 2016 13:39
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
I wish I could have placed a bet in Las Vegas as to how quickly some of the people
would jump in and say that these airplanes have X number of hours and Y number
of landings without failure. I would have been able to buy another Kolb :)
With all due respect to everyone, I KNOW that these airplanes are not falling out
of the sky.
Now, also with all due respect, can someone with engineering knowledge tell me,
ON A TECHNICAL ENGINEERING level, how it could EVER be considered as good design
practice to essentially cantilever a piano hinge off of a thin wall round
tube, with one line of rivets at the tangent contact point, and with flight loads
often perpendicular to that axis, where that cantilever loaded hinge is not
only connecting two pieces of primary aircraft structure but also attaching
a primary control surface ?
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Tue, 3/22/16, Dennis Rowe wrote:
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
To: kolb-list(at)matronics.com
Date: Tuesday, March 22, 2016, 9:59 AM
Dennis Rowe
Somebody notify John Hauck, as Miss Pfer has around 4000
hours on her airframe and has taken an eighty horse and two
100 horse Rotax 912 engines well toward their TBO! The
horizontal stabilizer must be ready to fall off at any
second.
Maybe I can get a good deal on her since her demise must be
imminent.
Bill, just build the dang Firestar to plans and fly it. It
won't fall apart.
Dennis "Skid" Rowe
Mk-3 Rotax 690, with a stock Kolb empennage.
> On Mar 21, 2016, at 6:29 PM, Bill Berle
wrote:
>
>
> I hope I'm wrong, but my review of the plans indicated
that there is no traditional DIRECT structural connection
between the rear spar tube and the fuselage tube. All the
load paths have to take a serpentine route and go rearward
through the elevator hinges first, and only then into the
U-joint and pivot bolt in the steel ring. If you removed the
elevator hinges (from either the elevator or the
stabilizer), or if you took the pin out of the hinges, you
could move the stabilizer up and down freely while the
elevator remained bolted to the fuselage.
>
> Even WITH all the hinges in place, all up and down
movement of the stabilizer is transmitted through the rivets
that hold the hinge onto the tubes, and there is no
significant stiffness or bracing against this movement.
Essentially you could move the root end of the stabilizer up
and down by hand and this movement would bend the
(un-supported section of) the hinge material. This would
attempt to pry the rivets out of the tube and/or bend the
thin metal back and forth.
>
> Also, because of this design the forward stabilizer
attach bolt must be a loose fit, and the stabilizer has to
be able to slide back and forth a little.
>
> The only thing that is gained by this unusual
structural load path is that 4 ounces of weight for a pair
of fittings (at the rear stabilizer spar) is saved. Can any
one explain to me why this was a good bargain?
>
> Bill Berle
> www.ezflaphandle.com - safety & performance
upgrade for light aircraft
> www.grantstar.net
- winning proposals for non-profit and
for-profit entities
>
> --------------------------------------------
> On Mon, 3/21/16, Richard Girard
wrote:
>
> Subject: Re: Kolb-List: Elevator/Stabilizer hinge
ass'y
> To: "kolb-list(at)matronics.com"
> Date: Monday, March 21, 2016, 2:40 PM
>
> The rear attachment
> of the horizontal stabilizer is NOT through the hinge.
It is
> through the rear folding weldments that also act as
the
> inner hinge. When it is set up correctly the hinge line
is
> on the same center as the swivel bolt in the weldment,
> however there is some allowance for misalignment. In
that
> case the weldment in the elevator spar (forward tube of
the
> elevator), can slide on the bolt in the swivel
> weldment.I've seen folding mechanisms on the Kit
> Fox and repaired the mechanism on the Highlander and in
my
> HO Homer's is the most clever. All you have to do to
> fold the HS on a Kolb is to take out a single bolt
that
> attaches the lower wires to the rudder post. I'm not
> sure how you would make it any simpler.
> Rick Girard
> On Mon, Mar 21, 2016
> at 12:55 PM, Bill Berle
> wrote:
> Bill Berle
>
>
>
> Are there any Kolb people on this list who are
qualified
> mechanical or aero-structure engineers? I want to ask
a
> question about the tail attachment mechanism.
>
>
>
> Before I even mention the question, I want to assure
> everyone that I AM COMPLETELY AWARE that there are X
> thousand Kolbs flying around safely with this
stabilizer
> attachment. I understand that there have not been many
(or
> perhaps any) failures of this mechanism. What I am
asking
> about is the theoretical "correctness" of the
> design, and whether any other "old-school"
> airplane people think that this system is a little
wonky.
>
>
>
> It took a few moments to finally understand how the
> mechanism works, and after looking at everything
several
> times it was clear that there is no direct structural
> attachment between the main spar tube of the stabilizer
to
> the fuselage tube (tailboom). The primary structural
load
> path between the root end of the main stabilizer spar
tube
> and the fuselage is transmitted through the elevator
> hinge... and this hinge isn't even the aircraft style
> extruded hinge.
>
>
>
> So if the air loads try to lift up or push down on the
root
> end of the stabilizer, it puts all that load through
the
> hinge, into the elevator pivot, and then finally into
the
> steel ring at the back of the fuselage.
>
>
>
> But that's not even the biggest issue in my head. The
> larger issue is that (according to plan) the flat hinge
is
> riveted to the tubes along one thin "point of
> contact" line tangent to the tube. So the root
> stabilizer load is all acting on a hinge, which itself
is
> cantilevered off of one tangent point on the
tube.
>
>
>
> Now I'm not a degreed engineer, and I'm not a
> mathematician. So I called a friend of mine who is a
retired
> aerospace structural engineer, with 50+ years of
experience.
> I showed him the plans and explained my concern, and I
was
> informed that my concerns about this system were valid.
My
> Kolb will be built with a more stable attachment.
>
>
>
> My question for any real, degreed, qualified,
> aircraft-experience engineers is... has anyone looked
at the
> stabilizer root attachment load path and had these
same
> concerns?
>
>
>
> ONCE AGAIN, this is not an attack on Mr. Kolb or his
design,
> and it is not intended to cause any panic or concern at
this
> point. What I want to know is why this load path -
through
> two tangent mounted hinge halves, into a movable
elevator,
> and then into the fuselage - is good enough, and why it
was
> not appropriate to install an attachment bracket onto
the
> fuselage at the rear stabilizer spar.
>
>
>
>
>
> Bill Berle
>
> www.ezflaphandle.com
> - safety & performance upgrade for light aircraft
>
> www.grantstar.net
> - winning proposals for
non-profit and for-profit
> entities
>
>
>
>
>
> ==========
>
> br>
> fts!)
>
> r>
>>
> w.buildersbooks.com" rel="noreferrer"
> target="_blank">www.buildersbooks.com
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
>
> -Matt
Dralle, List Admin.
>
> ==========
>
> -List" rel="noreferrer"
> target="_blank">http://www.matronics.com/Navigator?Kolb-List
>
> ==========
>
> FORUMS -
>
> eferrer"
> target="_blank">http://forums.matronics.com
>
> ==========
>
> b Site -
>
> -Matt
Dralle, List Admin.
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
>
> ==========
>
>
>
>
>
>
>
>
>
>
> --
> Blessed
> are the cracked, for they shall let in the
light. Groucho
> Marx
>
>
>
>
>
>
Lists This Month --
Some AWESOME FREE Gifts!)
Raiser. Click on
more about
Gifts provided
www.buildersbooks.com
-Matt
Dralle, List Admin.
Forum -
- MATRONICS WEB FORUMS -
List Contribution Web Site -
-Matt
Dralle, List Admin.
________________________________________________________________________________
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
| From: | Larry Cottrell <lcottrell1020(at)gmail.com> |
Berle wrote:
"I wish I could have placed a bet in Las Vegas as to how quickly some of th
e
people would jump in and say that these airplanes have X number of hours an
d
Y number of landings without failure. I would have been able to buy another
Kolb :)"
Not to put too fine a point on the discussion, but the reason that you
heard the phrase that you knew would be coming, is that we too have seen
this all before as well. I have at least one friend that always had to
improve every thing that he bought, simply because that was his disease.
That's ok, what ever spins your prop. If reinventing the wheel is your
thing, give er hell.
I have had VG's for years, as have quite a few of the guys. I have had 4130
longer gear legs for at least a couple of years, so have quite a few of the
guy's. Yep, it helps the plane perform better. I have also crashed at least
three times and the worst that I got besides humility was a sprained left
middle finger. So I personally am a fan of the way that Homer designed the
plane. It fits my mission perfectly.
If the one that you bought does not fit the mission as you see it, by all
means tweak it any way that makes you happy.
I have also seen several guys on the list that were convinced that a bit of
this and a bit of that would make the plane perform just fine with one of
the other types of engines. I don't think any of them are still flying them
because it turned a perfectly fine plane into something that flew like a
C150, and was about as much fun to fly as watching grass grow. Again, you
are a big boy, and apparently you have a better idea, by all mean have at
it. I know one guy that just had to have a 1/2 VW on his plane. We on the
list went through about 2 years of trying and eventually he gave up, sold
the plane and never flew again.
So you see, we too have seen some of this before. Now I personally don't
want to hurt your feelings, but the little smiley face in your message
didn't quite take all the sting out of your last post. We will see if I can
do a bit better, or at least as good. No body here cares if you can improve
your plane. It is your and yours alone, tweak it any way you like. If it is
a real improvement we might want to do the same, just try to not tell me
how stupid I am because mine does just exactly what I want and need. :-)
Larry
On Tue, Mar 22, 2016 at 1:33 PM, Bob wrote:
>
> I suffer from the same 50 year malady you mentioned earlier, but would
> suggest you propose to your aero/ structures engineer
> friend a couple of alternate details. I would agree that the structural
> configuration is non standard, with the appearance of some odd geometric
> coupling, but it has clearly worked well for many years and tens of
> thousands of hours fleet time regardless of the Las Vegas odd makers.
>
> The main point is the loads are very small compared to the strength of th
e
> hardware...arguably by more than an order of magnitude.
>
> Flying downloads on the horizontal tail are probably in the
> 50 lb maybe 100 lb at the most to provide flyable static pitch and speed
> stability. Low aspect ratio and taper puts the center of pressure fairly
> close to the wire bracing attachments, probably forward and inboard, so
> most
> of these downloads are taken out as tension in those wires and compressio
n
> in the vertical stabilizer tube. Smaller loads are reacted at the root
> bolts and across the hinges. One would not attempt to design the structu
re
> for full elevator deflection at
> Vne, so reasonably one would only ever see relatively modest changes in t
he
> aero down loads throughout the flight spectrum. A fairly extreme case th
at
> would develop very high pitch rates and require elevator correction would
> be
> full power to idle or the reverse. That would produce about 300 lb of
> force
> at maybe 2 ft
> above the cg and would require a change in tail download of about
> 40 lb assuming the moment arm is about 15 ft. So that=99s 20 lb pe
r side.
> Each of the hinge rivets assuming they are 1/8th inch is good for 120 lbs
> single shear. The load is shared by lots of rivets. The bolts are I
> believe 5/16 which are good for 5,500 lb single shear even if only grade
5.
> I would argue that the hinges, dozens of rivets and large diameter pivoti
ng
> bolts appear
> to be overdesigned for the basic small aero loads of this aircraft.
> Fatigue
> loads from the prop wash swirl could be an issue,
> but apparently not from fleet experience.
>
> Ultimate static strength is most likely dictated by the aluminum tubing
> substructure, not by the rivets, hinges, or support bolts....
>
> I recommend not trying to improve the design!
>
> Bob
>
>
> -----Original Message----- From: Bill Berle
> Sent: Tuesday, March 22, 2016 10:39 AM
> To: kolb-list(at)matronics.com
> Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
>
>
> I wish I could have placed a bet in Las Vegas as to how quickly some of t
he
> people would jump in and say that these airplanes have X number of hours
> and
> Y number of landings without failure. I would have been able to buy anoth
er
> Kolb :)
>
> With all due respect to everyone, I KNOW that these airplanes are not
> falling out of the sky.
>
> Now, also with all due respect, can someone with engineering knowledge te
ll
> me, ON A TECHNICAL ENGINEERING level, how it could EVER be considered as
> good design practice to essentially cantilever a piano hinge off of a thi
n
> wall round tube, with one line of rivets at the tangent contact point, an
d
> with flight loads often perpendicular to that axis, where that cantilever
> loaded hinge is not only connecting two pieces of primary aircraft
> structure
> but also attaching a primary control surface ?
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and
> for-profit entities
>
> --------------------------------------------
> On Tue, 3/22/16, Dennis Rowe wrote:
>
> Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
> To: kolb-list(at)matronics.com
> Date: Tuesday, March 22, 2016, 9:59 AM
>
> Dennis Rowe
>
> Somebody notify John Hauck, as Miss Pfer has around 4000
> hours on her airframe and has taken an eighty horse and two
> 100 horse Rotax 912 engines well toward their TBO! The
> horizontal stabilizer must be ready to fall off at any
> second.
> Maybe I can get a good deal on her since her demise must be
> imminent. =F0=9F=98=89
> Bill, just build the dang Firestar to plans and fly it. It
> won't fall apart.
>
>
> Dennis "Skid" Rowe
> Mk-3 Rotax 690, with a stock Kolb empennage.=F0=9F=98=B1
>
>
> On Mar 21, 2016, at 6:29 PM, Bill Berle
>>
> wrote:
>
>>
>>
>> I hope I'm wrong, but my review of the plans indicated
>>
> that there is no traditional DIRECT structural connection
> between the rear spar tube and the fuselage tube. All the
> load paths have to take a serpentine route and go rearward
> through the elevator hinges first, and only then into the
> U-joint and pivot bolt in the steel ring. If you removed the
> elevator hinges (from either the elevator or the
> stabilizer), or if you took the pin out of the hinges, you
> could move the stabilizer up and down freely while the
> elevator remained bolted to the fuselage.
>
>>
>> Even WITH all the hinges in place, all up and down
>>
> movement of the stabilizer is transmitted through the rivets
> that hold the hinge onto the tubes, and there is no
> significant stiffness or bracing against this movement.
> Essentially you could move the root end of the stabilizer up
> and down by hand and this movement would bend the
> (un-supported section of) the hinge material. This would
> attempt to pry the rivets out of the tube and/or bend the
> thin metal back and forth.
>
>>
>> Also, because of this design the forward stabilizer
>>
> attach bolt must be a loose fit, and the stabilizer has to
> be able to slide back and forth a little.
>
>>
>> The only thing that is gained by this unusual
>>
> structural load path is that 4 ounces of weight for a pair
> of fittings (at the rear stabilizer spar) is saved. Can any
> one explain to me why this was a good bargain?
>
>>
>> Bill Berle
>> www.ezflaphandle.com - safety & performance
>>
> upgrade for light aircraft
>
>> www.grantstar.net
>>
> - winning proposals for non-profit and
> for-profit entities
>
>>
>> --------------------------------------------
>> On Mon, 3/21/16, Richard Girard
>>
> wrote:
>
>>
>> Subject: Re: Kolb-List: Elevator/Stabilizer hinge
>>
> ass'y
>
>> To: "kolb-list(at)matronics.com"
>>
>
>
>> Date: Monday, March 21, 2016, 2:40 PM
>>
>> The rear attachment
>> of the horizontal stabilizer is NOT through the hinge.
>>
> It is
>
>> through the rear folding weldments that also act as
>>
> the
>
>> inner hinge. When it is set up correctly the hinge line
>>
> is
>
>> on the same center as the swivel bolt in the weldment,
>> however there is some allowance for misalignment. In
>>
> that
>
>> case the weldment in the elevator spar (forward tube of
>>
> the
>
>> elevator), can slide on the bolt in the swivel
>> weldment.I've seen folding mechanisms on the Kit
>> Fox and repaired the mechanism on the Highlander and in
>>
> my
>
>> HO Homer's is the most clever. All you have to do to
>> fold the HS on a Kolb is to take out a single bolt
>>
> that
>
>> attaches the lower wires to the rudder post. I'm not
>> sure how you would make it any simpler.
>> Rick Girard
>> On Mon, Mar 21, 2016
>> at 12:55 PM, Bill Berle
>> wrote:
>> Bill Berle
>>
>>
>>
>> Are there any Kolb people on this list who are
>>
> qualified
>
>> mechanical or aero-structure engineers? I want to ask
>>
> a
>
>> question about the tail attachment mechanism.
>>
>>
>>
>> Before I even mention the question, I want to assure
>> everyone that I AM COMPLETELY AWARE that there are X
>> thousand Kolbs flying around safely with this
>>
> stabilizer
>
>> attachment. I understand that there have not been many
>>
> (or
>
>> perhaps any) failures of this mechanism. What I am
>>
> asking
>
>> about is the theoretical "correctness" of the
>> design, and whether any other "old-school"
>> airplane people think that this system is a little
>>
> wonky.
>
>>
>>
>>
>> It took a few moments to finally understand how the
>> mechanism works, and after looking at everything
>>
> several
>
>> times it was clear that there is no direct structural
>> attachment between the main spar tube of the stabilizer
>>
> to
>
>> the fuselage tube (tailboom). The primary structural
>>
> load
>
>> path between the root end of the main stabilizer spar
>>
> tube
>
>> and the fuselage is transmitted through the elevator
>> hinge... and this hinge isn't even the aircraft style
>> extruded hinge.
>>
>>
>>
>> So if the air loads try to lift up or push down on the
>>
> root
>
>> end of the stabilizer, it puts all that load through
>>
> the
>
>> hinge, into the elevator pivot, and then finally into
>>
> the
>
>> steel ring at the back of the fuselage.
>>
>>
>>
>> But that's not even the biggest issue in my head. The
>> larger issue is that (according to plan) the flat hinge
>>
> is
>
>> riveted to the tubes along one thin "point of
>> contact" line tangent to the tube. So the root
>> stabilizer load is all acting on a hinge, which itself
>>
> is
>
>> cantilevered off of one tangent point on the
>>
> tube.
>
>>
>>
>>
>> Now I'm not a degreed engineer, and I'm not a
>> mathematician. So I called a friend of mine who is a
>>
> retired
>
>> aerospace structural engineer, with 50+ years of
>>
> experience.
>
>> I showed him the plans and explained my concern, and I
>>
> was
>
>> informed that my concerns about this system were valid.
>>
> My
>
>> Kolb will be built with a more stable attachment.
>>
>>
>>
>> My question for any real, degreed, qualified,
>> aircraft-experience engineers is... has anyone looked
>>
> at the
>
>> stabilizer root attachment load path and had these
>>
> same
>
>> concerns?
>>
>>
>>
>> ONCE AGAIN, this is not an attack on Mr. Kolb or his
>>
> design,
>
>> and it is not intended to cause any panic or concern at
>>
> this
>
>> point. What I want to know is why this load path -
>>
> through
>
>> two tangent mounted hinge halves, into a movable
>>
> elevator,
>
>> and then into the fuselage - is good enough, and why it
>>
> was
>
>> not appropriate to install an attachment bracket onto
>>
> the
>
>> fuselage at the rear stabilizer spar.
>>
>>
>>
>>
>>
>> Bill Berle
>>
>> www.ezflaphandle.com
>> - safety & performance upgrade for light aircraft
>>
>> www.grantstar.net
>> - winning proposals for
>>
> non-profit and for-profit
>
>> entities
>>
>>
>>
>>
>>
>> ==========
>>
>> br>
>> fts!)
>>
>> r>
>>
>>>
>>> w.buildersbooks.com" rel="noreferrer"
>> target="_blank">www.buildersbooks.com
>>
>> rel="noreferrer"
>> target="_blank">http://www.matronics.com/contribution
>>
>> -Matt
>>
> Dralle, List Admin.
>
>>
>> ==========
>>
>> -List" rel="noreferrer"
>> target="_blank">http://www.matronics.com/Navigator?Kolb-List
>>
>> ==========
>>
>> FORUMS -
>>
>> eferrer"
>> target="_blank">http://forums.matronics.com
>>
>> ==========
>>
>> b Site -
>>
>> -Matt
>>
> Dralle, List Admin.
>
>>
>> rel="noreferrer"
>> target="_blank">http://www.matronics.com/contribution
>>
>> ==========
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> --
>> =9CBlessed
>> are the cracked, for they shall let in the
>>
> light.=9D Groucho
>
>> Marx
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>>
>>
>>
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>>
>
> Lists This Month --
> Some AWESOME FREE Gifts!)
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*If you forward this email, or any part of it, please remove my email
address before sending.*
________________________________________________________________________________
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
| From: | Rick Neilsen <neilsenrm(at)gmail.com> |
Bill
It might be helpful to look at a completed airplane. You may not be
visualizing correctly the drawings you are looking at. The design works and
it can be folded.
Years ago we had a guy that felt he had to fix everything on the Kolb MKIII
that he was building. He made a valiant effort in completing the plane. He
must have spent 3-4 thousand extra hours working on all the changes.
Luckily he never completed the airplane. He was a great guy and is still
alive because he didn't ever fly that plane.
My advice is build the plane exactly by the plans. There are a few really
good changes that a few people have tried to tell you about but???
If you absolutely must make all the changes you are talking about get real
good insurance for your love ones and DO NOT call it a Kolb. Don't even
mention it started as a Kolb kit. Also please quit talking about all the
issues you think are wrong, somebody might think you know what you are
talking about and hurt themselves too. Sorry the proof is in the massive
hours in the fleet.
Did anyone ever tell you about one of the Kolb employees that took a plane
up and intentionally tried to tear the plane apart. He finally with
considerable effort ripped the wings off, he threw out a chute and later
fixed the point of failure. Our planes are well designed and tested.
Even with all that evidence I will still say my advice is worth what you
paid for it.
Rick Neilsen
Redrive VW Powered
On Tue, Mar 22, 2016 at 1:39 PM, Bill Berle
wrote:
>
> I wish I could have placed a bet in Las Vegas as to how quickly some of
> the people would jump in and say that these airplanes have X number of
> hours and Y number of landings without failure. I would have been able to
> buy another Kolb :)
>
> With all due respect to everyone, I KNOW that these airplanes are not
> falling out of the sky.
>
> Now, also with all due respect, can someone with engineering knowledge
> tell me, ON A TECHNICAL ENGINEERING level, how it could EVER be considere
d
> as good design practice to essentially cantilever a piano hinge off of a
> thin wall round tube, with one line of rivets at the tangent contact poin
t,
> and with flight loads often perpendicular to that axis, where that
> cantilever loaded hinge is not only connecting two pieces of primary
> aircraft structure but also attaching a primary control surface ?
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and
> for-profit entities
>
> --------------------------------------------
> On Tue, 3/22/16, Dennis Rowe wrote:
>
> Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
> To: kolb-list(at)matronics.com
> Date: Tuesday, March 22, 2016, 9:59 AM
>
> Dennis Rowe
>
> Somebody notify John Hauck, as Miss Pfer has around 4000
> hours on her airframe and has taken an eighty horse and two
> 100 horse Rotax 912 engines well toward their TBO! The
> horizontal stabilizer must be ready to fall off at any
> second.
> Maybe I can get a good deal on her since her demise must be
> imminent. =F0=9F=98=89
> Bill, just build the dang Firestar to plans and fly it. It
> won't fall apart.
>
>
> Dennis "Skid" Rowe
> Mk-3 Rotax 690, with a stock Kolb empennage.=F0=9F=98=B1
>
>
> > On Mar 21, 2016, at 6:29 PM, Bill Berle
> wrote:
> >
>
> >
> > I hope I'm wrong, but my review of the plans indicated
> that there is no traditional DIRECT structural connection
> between the rear spar tube and the fuselage tube. All the
> load paths have to take a serpentine route and go rearward
> through the elevator hinges first, and only then into the
> U-joint and pivot bolt in the steel ring. If you removed the
> elevator hinges (from either the elevator or the
> stabilizer), or if you took the pin out of the hinges, you
> could move the stabilizer up and down freely while the
> elevator remained bolted to the fuselage.
> >
> > Even WITH all the hinges in place, all up and down
> movement of the stabilizer is transmitted through the rivets
> that hold the hinge onto the tubes, and there is no
> significant stiffness or bracing against this movement.
> Essentially you could move the root end of the stabilizer up
> and down by hand and this movement would bend the
> (un-supported section of) the hinge material. This would
> attempt to pry the rivets out of the tube and/or bend the
> thin metal back and forth.
> >
> > Also, because of this design the forward stabilizer
> attach bolt must be a loose fit, and the stabilizer has to
> be able to slide back and forth a little.
> >
> > The only thing that is gained by this unusual
> structural load path is that 4 ounces of weight for a pair
> of fittings (at the rear stabilizer spar) is saved. Can any
> one explain to me why this was a good bargain?
> >
> > Bill Berle
> > www.ezflaphandle.com - safety & performance
> upgrade for light aircraft
> > www.grantstar.net
> - winning proposals for non-profit and
> for-profit entities
> >
> > --------------------------------------------
> > On Mon, 3/21/16, Richard Girard
> wrote:
> >
> > Subject: Re: Kolb-List: Elevator/Stabilizer hinge
> ass'y
> > To: "kolb-list(at)matronics.com"
>
> > Date: Monday, March 21, 2016, 2:40 PM
> >
> > The rear attachment
> > of the horizontal stabilizer is NOT through the hinge.
> It is
> > through the rear folding weldments that also act as
> the
> > inner hinge. When it is set up correctly the hinge line
> is
> > on the same center as the swivel bolt in the weldment,
> > however there is some allowance for misalignment. In
> that
> > case the weldment in the elevator spar (forward tube of
> the
> > elevator), can slide on the bolt in the swivel
> > weldment.I've seen folding mechanisms on the Kit
> > Fox and repaired the mechanism on the Highlander and in
> my
> > HO Homer's is the most clever. All you have to do to
> > fold the HS on a Kolb is to take out a single bolt
> that
> > attaches the lower wires to the rudder post. I'm not
> > sure how you would make it any simpler.
> > Rick Girard
> > On Mon, Mar 21, 2016
> > at 12:55 PM, Bill Berle
> > wrote:
> > Bill Berle
> >
> >
> >
> > Are there any Kolb people on this list who are
> qualified
> > mechanical or aero-structure engineers? I want to ask
> a
> > question about the tail attachment mechanism.
> >
> >
> >
> > Before I even mention the question, I want to assure
> > everyone that I AM COMPLETELY AWARE that there are X
> > thousand Kolbs flying around safely with this
> stabilizer
> > attachment. I understand that there have not been many
> (or
> > perhaps any) failures of this mechanism. What I am
> asking
> > about is the theoretical "correctness" of the
> > design, and whether any other "old-school"
> > airplane people think that this system is a little
> wonky.
> >
> >
> >
> > It took a few moments to finally understand how the
> > mechanism works, and after looking at everything
> several
> > times it was clear that there is no direct structural
> > attachment between the main spar tube of the stabilizer
> to
> > the fuselage tube (tailboom). The primary structural
> load
> > path between the root end of the main stabilizer spar
> tube
> > and the fuselage is transmitted through the elevator
> > hinge... and this hinge isn't even the aircraft style
> > extruded hinge.
> >
> >
> >
> > So if the air loads try to lift up or push down on the
> root
> > end of the stabilizer, it puts all that load through
> the
> > hinge, into the elevator pivot, and then finally into
> the
> > steel ring at the back of the fuselage.
> >
> >
> >
> > But that's not even the biggest issue in my head. The
> > larger issue is that (according to plan) the flat hinge
> is
> > riveted to the tubes along one thin "point of
> > contact" line tangent to the tube. So the root
> > stabilizer load is all acting on a hinge, which itself
> is
> > cantilevered off of one tangent point on the
> tube.
> >
> >
> >
> > Now I'm not a degreed engineer, and I'm not a
> > mathematician. So I called a friend of mine who is a
> retired
> > aerospace structural engineer, with 50+ years of
> experience.
> > I showed him the plans and explained my concern, and I
> was
> > informed that my concerns about this system were valid.
> My
> > Kolb will be built with a more stable attachment.
> >
> >
> >
> > My question for any real, degreed, qualified,
> > aircraft-experience engineers is... has anyone looked
> at the
> > stabilizer root attachment load path and had these
> same
> > concerns?
> >
> >
> >
> > ONCE AGAIN, this is not an attack on Mr. Kolb or his
> design,
> > and it is not intended to cause any panic or concern at
> this
> > point. What I want to know is why this load path -
> through
> > two tangent mounted hinge halves, into a movable
> elevator,
> > and then into the fuselage - is good enough, and why it
> was
> > not appropriate to install an attachment bracket onto
> the
> > fuselage at the rear stabilizer spar.
> >
> >
> >
> >
> >
> > Bill Berle
> >
> > www.ezflaphandle.com
> > - safety & performance upgrade for light aircraft
> >
> > www.grantstar.net
> > - winning proposals for
> non-profit and for-profit
> > entities
> >
> >
> >
> >
> >
> > ==========
> >
> > br>
> > fts!)
> >
> > r>
> >>
> > w.buildersbooks.com" rel="noreferrer"
> > target="_blank">www.buildersbooks.com
> >
> > rel="noreferrer"
> > target="_blank">http://www.matronics.com/contribution
> >
> > -Matt
> Dralle, List Admin.
> >
> > ==========
> >
> > -List" rel="noreferrer"
> > target="_blank">http://www.matronics.com/Navigator?Kolb-List
> >
> > ==========
> >
> > FORUMS -
> >
> > eferrer"
> > target="_blank">http://forums.matronics.com
> >
> > ==========
> >
> > b Site -
> >
> > -Matt
> Dralle, List Admin.
> >
> > rel="noreferrer"
> > target="_blank">http://www.matronics.com/contribution
> >
> > ==========
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > --
> > =9CBlessed
> > are the cracked, for they shall let in the
> light.=9D Groucho
> > Marx
> >
> >
> >
> >
> >
> >
>
>
> Lists This Month --
> Some AWESOME FREE Gifts!)
> Raiser. Click on
> more about
> Gifts provided
> www.buildersbooks.com
> -Matt
> Dralle, List Admin.
> Forum -
> - MATRONICS WEB FORUMS -
> List Contribution Web Site -
> -Matt
> Dralle, List Admin.
>
>
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>
>
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | Elevator/Stabilizer hinge ass'y |
Thank you all for the replies. I appreciate the opportunity to discuss this, without
people thinking that I am trashing the aircraft, or insulting Mr. Kolb's
legacy.
Yes I had considered that some part of the tail loads are carried by the brace
wires, this is why I referred to the questionable part as the stabilizer "root
loads" instead of the whole stabilizer. Of course, just like a strut braced wing
there is a large "inward" (compression) load on the tube, but since the elevator
is tapered there is still a large portion of the force generated that is
vertical at the root end.
Those rivets holding the hinge may well be capable of 120 pounds in shear, or perhaps
even in tension. I have no quarrel whatsoever with the strength of the
rivets on such a light and slow aircraft. And yes there are a lot of them.
But the angular ORIENTATION of the hinges, and the fact that the hinges are somewhat
"cantilevered" as I have called it, puts a "peel" load on those fasteners,
like a crow bar trying to peel and pop the heads off the rivets at an angle.
That is probably the worst case for those rivets. The failure mode would be
that the loads are rocking the rivets slowly back and forth, loosening them.
Also, the hinges themselves are not designed for the loads to be hanging out 3/8
or 1/2 inch from their attachment, like a diving board.
One person replied that I may not be understanding the mechanism, and how it folds,
and that the front attachment moves a little. I have taken a little time
to study the plans and try to understand this. I believe that I understand it
(whether I agree with the design or not). If the rear stabilizer attachment is
in fact located on exactly the same axis as the elevator hinge, then the front
of the stabilizer should not need to move fore and aft at all with elevator
deflection. Elevator deflection could create fore-aft (or up-down) movement ONLY
if there IS some amount of offset between the hinge axis and the rear stabilizer
mounting. If the two axes are concentric, there could not be any linear
motion by definition.
I believe that the only reason the front stabilizer attachment has to be able to
slide a little is because in reality for the average builder it is very difficult
to locate the hinges at precisely the center of the welded elevator horn/
pivot mechanism. Without any jig or fixture to guarantee the exact location
of the hinge pin in open space, it is etoo asy for the hinge pin to be a little
bit fore-aft or up-down... while the holes are drilled and the rivets are installed.
So I am guessing that to make it easier for the builder, and to prevent binding
and cracking of the parts, the front attachment was left a little loose and the
rear attachment was eliminated.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | Addendum - Elevator/Stabilizer hinge ass'y |
With all sincerest respect to Mr. Wainfan and any other great engineers out there
who might be monitoring this discussion, the credentials and field experience
of the engineer (who I asked to review the elevator attachment) are high enough
for the purposes of settling any questions about the appropriateness of any
particular aircraft structure.
He is a graduate of the 1950's DeHavilland Aircraft Engineering program in England
(from youth apprenticeship up through engineering degree in aerostructures
and metallurgy), and I believe Arnold Schwarzenegger cannot physically lift his
aerospace resume' . Any further comment on his achievements or abilities would
sound like an infomercial, so I will leave it at that.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Tue, 3/22/16, Stuart Harner wrote:
Subject: RE: Kolb-List: Elevator/Stabilizer hinge ass'y
To: kolb-list(at)matronics.com
Date: Tuesday, March 22, 2016, 12:27 PM
"Stuart Harner"
Bill,
I am not an engineer but I did stay in a Holiday Inn last
night. :) No, not really, but I do have a fundamental
understanding of load transmission through a structure.
First a question, and please don't be offended. Have
you had an opportunity to observe the structure of the Kolb
tail while it was being folded and then again when it is
bolted into place? I asked this because I found a
couple of things in the plans of the Firefly that I did not
understand until I was able to actually see it live. Simply
put, I had trouble visualizing it from just the plans.
One thing that I think is missing from this discussion is
the loads carried by the brace wires. I would posit that
most of the forces from the tail that are transmitted to the
boom tube are carried by the braces. These, when properly
tensioned are actually pre-loaded slightly. This puts the
tubes in compression which makes the whole thing quite
strong. It also transfers the loads from the horizontals to
the steel post of the verticals which in turn is transferred
to the boom tube via the steel ring which is bolted and/or
riveted to the tube.
Of course some loads are transferred through the hinge
points and the front hinge must be able to slide slightly as
the elevator moves through its arc of travel. Could this be
made stronger? Of course, but not without sacrificing
something else such as weight or foldability. It is actually
a very clever design and I suspect that the majority of
loads that move through the rear hinge come from the
elevator and not the stabilizer.
I would also bet that the loads carried through the hinges
is far below the shear and tension limits of properly
installed rivets.
I am actually more "freaked out" by the fact that everything
in the tail depends on that one little 3/16" bolt (Firefly)
that holds the lower braces in place. Really, the threads on
that bolt are all there is between you and falling out of
the sky. To combat this irrationality I swap out the bolt
fairly often and the nuts even more often. If it really
bothered me, I would stay on the ground. :)
Perhaps you could send a copy of your plans to Barnaby
Wainfan and ask for his analysis. I hear he is a really nice
guy. From reading his articles over the years I am sure he
could provide the answers you seek.
As Uncle Red used to say: "Remember, if women don't find you
handsome, they should at least find you handy"
Stuart
-----Original Message-----
From: owner-kolb-list-server(at)matronics.com
[mailto:owner-kolb-list-server(at)matronics.com]
On Behalf Of Bill Berle
Sent: Monday, March 21, 2016 5:30 PM
To: kolb-list(at)matronics.com
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
I hope I'm wrong, but my review of the plans indicated that
there is no traditional DIRECT structural connection between
the rear spar tube and the fuselage tube. All the load paths
have to take a serpentine route and go rearward through the
elevator hinges first, and only then into the U-joint and
pivot bolt in the steel ring. If you removed the elevator
hinges (from either the elevator or the stabilizer), or if
you took the pin out of the hinges, you could move the
stabilizer up and down freely while the elevator remained
bolted to the fuselage.
Even WITH all the hinges in place, all up and down movement
of the stabilizer is transmitted through the rivets that
hold the hinge onto the tubes, and there is no significant
stiffness or bracing against this movement. Essentially you
could move the root end of the stabilizer up and down by
hand and this movement would bend the (un-supported section
of) the hinge material. This would attempt to pry the rivets
out of the tube and/or bend the thin metal back and forth.
Also, because of this design the forward stabilizer attach
bolt must be a loose fit, and the stabilizer has to be able
to slide back and forth a little.
The only thing that is gained by this unusual structural
load path is that 4 ounces of weight for a pair of fittings
(at the rear stabilizer spar) is saved. Can any one explain
to me why this was a good bargain?
Bill Berle
www.ezflaphandle.com - safety & performance
upgrade for light aircraft www.grantstar.net
- winning proposals for
non-profit and for-profit entities
--------------------------------------------
On Mon, 3/21/16, Richard Girard
wrote:
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
To: "kolb-list(at)matronics.com"
Date: Monday, March 21, 2016, 2:40 PM
The rear attachment
of the horizontal stabilizer is NOT through the hinge. It
is through the rear folding weldments that also act as
the inner hinge. When it is set up correctly the hinge
line is on the same center as the swivel bolt in the
weldment, however there is some allowance for
misalignment. In that case the weldment in the
elevator spar (forward tube of the elevator), can
slide on the bolt in the swivel weldment.I've seen
folding mechanisms on the Kit Fox and repaired the
mechanism on the Highlander and in my HO Homer's is
the most clever. All you have to do to fold the HS on
a Kolb is to take out a single bolt that attaches the
lower wires to the rudder post. I'm not sure how you
would make it any simpler.
Rick Girard
On Mon, Mar 21, 2016
at 12:55 PM, Bill Berle
wrote:
Bill Berle
Are there any Kolb people on this list who are
qualified mechanical or aero-structure engineers? I
want to ask a question about the tail attachment
mechanism.
Before I even mention the question, I want to assure
everyone that I AM COMPLETELY AWARE that there are X
thousand Kolbs flying around safely with this
stabilizer attachment. I understand that there have
not been many (or perhaps any) failures of this
mechanism. What I am asking about is the theoretical
"correctness" of the design, and whether any other
"old-school"
airplane people think that this system is a little wonky.
It took a few moments to finally understand how the
mechanism works, and after looking at everything
several times it was clear that there is no direct
structural attachment between the main spar tube of
the stabilizer to the fuselage tube (tailboom). The
primary structural load path between the root end of
the main stabilizer spar tube and the fuselage is
transmitted through the elevator hinge... and this
hinge isn't even the aircraft style extruded hinge.
So if the air loads try to lift up or push down on the
root end of the stabilizer, it puts all that load
through the hinge, into the elevator pivot, and then
finally into the steel ring at the back of the
fuselage.
But that's not even the biggest issue in my head. The
larger issue is that (according to plan) the flat hinge
is riveted to the tubes along one thin "point of
contact" line tangent to the tube. So the root
stabilizer load is all acting on a hinge, which itself
is cantilevered off of one tangent point on the
tube.
Now I'm not a degreed engineer, and I'm not a
mathematician. So I called a friend of mine who is a
retired aerospace structural engineer, with 50+ years
of experience.
I showed him the plans and explained my concern, and I
was informed that my concerns about this system were
valid. My Kolb will be built with a more stable
attachment.
My question for any real, degreed, qualified,
aircraft-experience engineers is... has anyone looked at
the stabilizer root attachment load path and had these
same concerns?
ONCE AGAIN, this is not an attack on Mr. Kolb or his
design, and it is not intended to cause any panic or
concern at this point. What I want to know is why this
load path - through two tangent mounted hinge halves,
into a movable elevator, and then into the fuselage -
is good enough, and why it was not appropriate to
install an attachment bracket onto the fuselage at the
rear stabilizer spar.
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for
non-profit and for-profit entities
==========
br>
fts!)
r>
>
w.buildersbooks.com" rel="noreferrer"
target="_blank">www.buildersbooks.com
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
-Matt Dralle,
List Admin.
==========
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target="_blank">http://www.matronics.com/Navigator?Kolb-List
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FORUMS -
eferrer"
target="_blank">http://forums.matronics.com
==========
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-Matt Dralle,
List Admin.
rel="noreferrer"
target="_blank">http://www.matronics.com/contribution
==========
--
Blessed
are the cracked, for they shall let in the
light.Groucho Marx
Lists This Month --
Some AWESOME FREE Gifts!)
Raiser. Click on
more about
Gifts provided
www.buildersbooks.com
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Dralle, List Admin.
Forum -
- MATRONICS WEB FORUMS -
List Contribution Web Site -
-Matt
Dralle, List Admin.
________________________________________________________________________________
| From: | Bill Berle <victorbravo(at)sbcglobal.net> |
| Subject: | Re: Elevator/Stabilizer hinge ass'y |
Wow. Please forgive me if anyone thought that I was being too aggressive or questioning.
Holy Mackerel, I was discussing innovation, experimentation, and individuality
in light aircraft construction.
Apparently there is no room for improvement in the design, and there were no compromises
made in manufacturing the kits. Thankfully, none of this reliance on
status quo was in force back when Mr. Kolb was experimenting with a new way to
build and improve on his personal aircraft designs.
My sincerest apology for the unintended effect of there being a "Sting" in any
of my comments. Absolutely unintentional.
>From this point I will try to constrain my questions and comments within direct
relevance to the existing design, or what has been done (or modified) already.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Tue, 3/22/16, Rick Neilsen wrote:
Subject: Re: Kolb-List: Elevator/Stabilizer hinge ass'y
To: "kolb-list(at)matronics.com"
Date: Tuesday, March 22, 2016, 1:19 PM
Bill
It might be helpful to look at a
completed airplane. You may not be visualizing correctly the
drawings you are looking at. The design works and it can be
folded.
Years ago we had a guy that felt he
had to fix everything on the Kolb MKIII that he was
building. He made a valiant effort in completing the plane.
He must have spent 3-4 thousand extra hours working on all
the changes. Luckily he never completed the airplane. He was
a great guy and is still alive because he didn't ever
fly that plane.
My advice is build the plane
exactly by the plans. There are a few really good changes
that a few people have tried to tell you about
but???
If you absolutely must make all the
changes you are talking about get real good insurance for
your love ones and DO NOT call it a Kolb. Don't even
mention it started as a Kolb kit. Also please quit talking
about all the issues you think are wrong, somebody might
think you know what you are talking about and hurt
themselves too. Sorry the proof is in the massive hours in
the fleet.
Did anyone ever tell you about one
of the Kolb employees that took a plane up and intentionally
tried to tear the plane apart. He finally with considerable
effort ripped the wings off, he threw out a chute and later
fixed the point of failure. Our planes are well designed and
tested.
Even with all that evidence I will
still say my advice is worth what you paid for it.
Rick NeilsenRedrive VW Powered
On Tue, Mar 22, 2016
at 1:39 PM, Bill Berle
wrote:
Bill Berle
I wish I could have placed a bet in Las Vegas as to
how quickly some of the people would jump in and say that
these airplanes have X number of hours and Y number of
landings without failure. I would have been able to buy
another Kolb :)
With all due respect to everyone, I KNOW that these
airplanes are not falling out of the sky.
Now, also with all due respect, can someone with engineering
knowledge tell me, ON A TECHNICAL ENGINEERING level, how it
could EVER be considered as good design practice to
essentially cantilever a piano hinge off of a thin wall
round tube, with one line of rivets at the tangent contact
point, and with flight loads often perpendicular to that
axis, where that cantilever loaded hinge is not only
connecting two pieces of primary aircraft structure but also
attaching a primary control surface ?
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and for-profit
entities
--------------------------------------------
On Tue, 3/22/16, Dennis
Rowe
wrote:
Subject: Re: Kolb-List: Elevator/Stabilizer hinge
ass'y
To: kolb-list(at)matronics.com
Date: Tuesday, March 22, 2016, 9:59 AM
Dennis Rowe
Somebody notify John Hauck, as Miss Pfer has around 4000
hours on her airframe and has taken an eighty horse and
two
100 horse Rotax 912 engines well toward their TBO! The
horizontal stabilizer must be ready to fall off at any
second.
Maybe I can get a good deal on her since her demise must
be
imminent.
Bill, just build the dang Firestar to plans and fly it.
It
won't fall apart.
Dennis "Skid" Rowe
Mk-3 Rotax 690, with a stock Kolb empennage.
> On Mar 21, 2016, at 6:29 PM, Bill Berle
wrote:
>
>
> I hope I'm wrong, but my review of the plans
indicated
that there is no traditional DIRECT structural connection
between the rear spar tube and the fuselage tube. All the
load paths have to take a serpentine route and go
rearward
through the elevator hinges first, and only then into the
U-joint and pivot bolt in the steel ring. If you removed
the
elevator hinges (from either the elevator or the
stabilizer), or if you took the pin out of the hinges,
you
could move the stabilizer up and down freely while the
elevator remained bolted to the fuselage.
>
> Even WITH all the hinges in place, all up and down
movement of the stabilizer is transmitted through the
rivets
that hold the hinge onto the tubes, and there is no
significant stiffness or bracing against this movement.
Essentially you could move the root end of the stabilizer
up
and down by hand and this movement would bend the
(un-supported section of) the hinge material. This would
attempt to pry the rivets out of the tube and/or bend the
thin metal back and forth.
>
> Also, because of this design the forward stabilizer
attach bolt must be a loose fit, and the stabilizer has
to
be able to slide back and forth a little.
>
> The only thing that is gained by this unusual
structural load path is that 4 ounces of weight for a
pair
of fittings (at the rear stabilizer spar) is saved. Can
any
one explain to me why this was a good bargain?
>
> Bill Berle
> www.ezflaphandle.com
- safety & performance
upgrade for light aircraft
> www.grantstar.net
- winning proposals for non-profit and
for-profit entities
>
> --------------------------------------------
> On Mon, 3/21/16, Richard Girard
wrote:
>
> Subject: Re: Kolb-List: Elevator/Stabilizer hinge
ass'y
> To: "kolb-list(at)matronics.com"
> Date: Monday, March 21, 2016, 2:40 PM
>
> The rear attachment
> of the horizontal stabilizer is NOT through the
hinge.
It is
> through the rear folding weldments that also act as
the
> inner hinge. When it is set up correctly the hinge
line
is
> on the same center as the swivel bolt in the
weldment,
> however there is some allowance for misalignment. In
that
> case the weldment in the elevator spar (forward tube
of
the
> elevator), can slide on the bolt in the swivel
> weldment.I've seen folding mechanisms on the Kit
> Fox and repaired the mechanism on the Highlander and
in
my
> HO Homer's is the most clever. All you have to do
to
> fold the HS on a Kolb is to take out a single bolt
that
> attaches the lower wires to the rudder post. I'm
not
> sure how you would make it any simpler.
> Rick Girard
> On Mon, Mar 21, 2016
> at 12:55 PM, Bill Berle
> wrote:
> Bill Berle
>
>
>
> Are there any Kolb people on this list who are
qualified
> mechanical or aero-structure engineers? I want to
ask
a
> question about the tail attachment mechanism.
>
>
>
> Before I even mention the question, I want to assure
> everyone that I AM COMPLETELY AWARE that there are X
> thousand Kolbs flying around safely with this
stabilizer
> attachment. I understand that there have not been
many
(or
> perhaps any) failures of this mechanism. What I am
asking
> about is the theoretical "correctness" of
the
> design, and whether any other "old-school"
> airplane people think that this system is a little
March 16, 2016 - March 22, 2016
Kolb-Archive.digest.vol-ns