Today's Message Index:
----------------------
1. 05:38 AM - Re: VG's, tail stall, angle of attack (John Hauck)
2. 06:35 AM - Sun and Fun 2017 (John Hauck)
3. 07:26 AM - Re: VG's, tail stall, angle of attack (phcpilot)
4. 08:11 AM - Re: VG's, tail stall, angle of attack (Rick Neilsen)
5. 09:38 AM - Re: Re: VG's, tail stall, angle of attack (Larry Cottrell)
6. 10:22 AM - Re: VG's, tail stall, angle of attack (Bill Berle)
7. 11:06 AM - Sun and Fun 2017 Canceled (for me) (John Hauck)
8. 11:11 AM - Re: VG's, tail stall, angle of attack (Rick Neilsen)
9. 11:12 AM - Re: VG's, tail stall, angle of attack (John Hauck)
10. 03:32 PM - Tail stall (B Young)
11. 04:27 PM - Re: Sun and Fun 2017 Canceled (for me) (George Helton)
Message 1
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| Subject: | VG's, tail stall, angle of attack |
Larry C/Kolbers:
I didn't fly yesterday, and I forgot what I did day before yesterday. Think I
put VGs on the horizontal stabilizer. ;-)
My job for many, many years was to fly prospective customers in the MKIII at Lakeland
and Oshkosh. I flew all kinds of shapes and sizes in a difficult environment
at best, lots of traffic, confined airstrip, wind, and turbulence. Never
had a elevator problem. On several occasions I did use extreme vigilance and
care flying a few super heavy passengers. Something I should not have done
at the time, and something I would not do in the future. One situation the customer
would not buy the airplane without a ride first. It was not the best
flying MKIII I had ever flown. I was pretty apprehensive about the flight. I
agreed to fly him out of Lakeland South where I had a lot more airstrip and less
traffic. This guy was what I called a "lopper". When he got in the right
seat he lopped over the aileron torque tube in the center of the aircraft. Made
it difficult for me to get my hand on the center mounted throttle. This was
a short flight, full throttle from take off to landing, one circuit around
the pattern. I was not going to take a chance of becoming a lawn dart.
I've never flown a Kolb that had an elevator problem, but when I was carrying large
passengers I always carried a little extra airspeed until I was back on the
ground.
john h
mkIII
Titus, Alabama
-----Original Message-----
From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Larry Cottrell
Sent: Monday, April 03, 2017 11:54 PM
Subject: Re: Kolb-List: VG's, tail stall, angle of attack
--> <lcottrell1020@gmail.com>
This whole thing is getting blown out of proportion. Boyd's and John's problem
concerned weight and CG change, caused by weight. I believe that the original
beginning of this thread came about concerning VG's on the wing, but none on the
elevator. Perhaps the language or description of the reasoning for why one
should also put them on the elevator was inadequate.
The "tail stall" that did or did not occur during landing was not a problem in
any other configuration other than landings. Even when it did occur upon landing,
it was in no way any more than a Hmmm factor of about 1. It was just that
I like others before me had learned, that the wing still had lift, with VG's,
long after the tail had dropped to the ground. Since this was occurring at 2 feet
above the ground, it was not Scary! It certainly is not a design flaw. :-)
Merely that you now had a lot more usable lift than you had before the installation
of VG's, and you could even out the lift between the wing and the elevator
by adding some of the little thingys on the elevator.
There! I hope that clears things up a bit.
Larry
On Mon, Apr 3, 2017 at 9:53 PM, Charlie England <ceengland7@gmail.com> wrote:
> --> <ceengland7@gmail.com>
>
> Don't know about Kolbs (yet) but tail stall isn't that uncommon in
> other a/c. The early Cessna Cardinal required a stabilator redesign
> due to tail stall.
>
> If answers are desired about whether there's a tail stall problem with
> a particular plane, why not install an angle of attack meter? Doesn't
> have to be high dollar; just an indicator that has consistent, repeatable readings.
>
> The wing always stalls at the same angle of attack. If the plane
> stalls at some arbitrary angle indication ('x') on your AOA when the
> plane is lightly loaded, and it stalls at some lower angle (y?) on the
> same indicator when heavily loaded and/or at a more forward CG, then
> the tail has stalled instead of the wing. If the plane stalls at the
> same AOA indication but a higher airspeed, then it's the wing that's stalling.
>
> Charlie
>
>
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Message 2
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| Subject: | Sun and Fun 2017 |
Talked to Bryan Melborn yesterday. Kolb Company was set up and ready to go
in Lakeland. He has a spot reserved for me and Miss P'fer for the week.
Almost ready to go. Don't know why it takes so much stuff to survive a few
days at Sun and Fun, but it does. One doesn't have to train to be
miserable, so I take all the things I need to be comfortable. I tie down
the MKIII in the Kolb display area and put my tent up under the wing. It is
super convenient for me. Don't have to go anywhere and all my stuff I need
to live is right where I am located.
It is 415 sm from Gantt International Airport to Lakeland, about 5.0 hours
flight time. I make one fuel stop in Cross City, Florida. That gives me
enough gas to fly to Lakeland and return to Cross City to refuel on the way
home. They always have free hot dogs and usually cheaper av gas, so I get
lunch both ways.
Weather is a little iffy when I get down southeast of Tallahassee, Florida.
I'm mentally prepared to take my time, find a comfortable place to hang out
if I do encounter thunder storms. This is a fun flight, no hurry, and no
deadline to make. The air show at Lakeland tends to be aggravating at
times. It usually lasts from 1400 to 1700 hours. Can't land during that
time frame. Also, the field is Day VFR only which is good until 2011
eastern time today. I can take my time and enjoy my flight.
The NOTAM for Paradise City says Day VFR Only. I printed out a copy of the
data from the Naval Observatory to back me up if I come into Lakeland as
late as 2011 tonight. Also printed out a copy of the Paradise City NOTAM.
Usually I get, from the volunteers that run the airfield, no flying after
1900 hours. Got to have my ammo in case they decide to attack me, which
they do at times. ;-)
Time go.
john h
mkIII
Titus, Alabama
Message 3
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| Subject: | Re: VG's, tail stall, angle of attack |
We shouldn't get upset because some people like to use correct and accurate terminology
when talking about a phenomenon.
Charlie, I think your response is brilliant. For those of us who do want to use
the correct term to describe what is happening I applaud your insight
and I can help with that. I make (and sell) an inexpensive Angle of Attack indicator
that dozens of people love. After my last batch of probes and gauges ran
out I haven't pushed it but am redesigning the probe for it and can offer it
again. There is a link to it on my site ranss7.com New faces will have the needle
more or less horizontal with red at the top (high angle) and green at the
bottom.
And on the subject of VG s on stab, aren't they usually placed just ahead of the
hinge line where the air is going to break as it goes over the elevator not
up near the leading edge???
If answers are desired about whether there's a tail stall problem with a
particular plane, why not install an angle of attack meter? Doesn't have
to be high dollar; just an indicator that has consistent, repeatable
readings.
The wing always stalls at the same angle of attack. If the plane stalls
at some arbitrary angle indication ('x') on your AOA when the plane is
lightly loaded, and it stalls at some lower angle (y?) on the same
indicator when heavily loaded and/or at a more forward CG, then the tail
has stalled instead of the wing. If the plane stalls at the same AOA
indication but a higher airspeed, then it's the wing that's stalling.
Charlie[/quote]
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=468032#468032
Attachments:
http://forums.matronics.com//files/face_black_side_push_143.jpg
Message 4
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| Subject: | Re: VG's, tail stall, angle of attack |
=8BI'm shocked!!! John H has put VGs on his airplane! I'm expecting s
ome
cataclysmic event to follow=8B!!!!
Years ago I witnessed and reported on the great VG fly off between John and
Richard Pike at a Kolb flyin. It should be in the archives so I won't go
back into the details here. But it was a tie.
I have some VGs on the sides of my fuselage at the wide point on my doors
and they do reduce the noise coming from the rear fuselage. I have plans to
someday put VGs on my wings and under my tail but it is a low priority. I
have a heavy engine and have put some major beef in the passenger
compartment including myself, I don't think anyone lapped but I can't say
that the old MKIIIC was ever less than capable of safely committing flight.
Also I saw the post about missing Buford, has something happened to him???
Rick Neilsen
Redrive VW Powered MKIIIC
Message 5
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| Subject: | Re: VG's, tail stall, angle of attack |
We shouldn't get upset because some people like to use correct and
accurate terminology when talking about a phenomenon.
And on the subject of VG s on stab, aren't they usually placed just
ahead of the hinge line where the air is going to break as it goes
over the elevator not up near the leading edge???
---------------------------------------------------------------------------------------------------------------------
I suppose that I shouldn't feel a bit chapped, as I volunteered to
take the blame for the wandering of this thread.----This is the
original:
Larry Cottrell <lcottrell1020@gmail.com>
Mar 31 (4 days ago)
to kolb-list
I have to admit that I am quite proud of you. Whether you believe it
or not, the ones on the elevator do help t keep the tail flying and
will also improve the landings. As I mentioned earlier, without them
the tail feathers stall before the wing.
---------------------------------------------------------------------------------------------
As far as the VG's are concerned they, to the best of my knowledge,
should be placed in front of the hinge line. Apparently they still do
quite well in other spots as well.
Inaccurately yours,
Larry
Message 6
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| Subject: | Re: VG's, tail stall, angle of attack |
What some folks might think of as a "tail stall" may just be air separating from
the elevator itself. So the entire tail is not technically stalled, but if the
air separates from the bottom of the elevator you would very likely see a reduction
in control authority. So maybe "elevator stall" is the better way to
describe it.
The flat cross section tails (no airfoil) would likely be more prone to this, because
the airflow forward of the hinge line is not as smooth or organized as
it would be on a properly airfoiled tail. But as we know, tens of thousands of
Cubs, Taylorcrafts, Aeroncas, Porterfields, and Kolbs are flying safely without
an airfoiled tail. The "flat" tail is simply a compromise to make the airplanes
easier and/or less costly to build. On a 70-90 MPH airplane it is an easy
and worthwhile compromise to make.
As a non-Kolb point of reference, I have an old Cessna 172 (1956, first year).
Anyone with Cessna 172 time will verify that the airplanes are kind of nose-heavy
with the rear seats empty, and that you basically "run out of elevator" when
you are trying to do a minimum speed landing with one or two people in the
front seats. What happens is that you feel the yoke (stick) hit the control stop,
and you can't raise the nose any more, even though you can feel the airplane
was willing to slow down a little more.
But then I woke up one Christmas morning (in August), and in the middle of the
night Santa Claus had installed little plastic VG's on the bottom of my horizontal
stabilizer. As I was flying the aircraft directly to the Oklahoma City FAA
office to report Santa for breaking the rules, I noticed that I was able to
raise the nose of the Cessna just a little bit higher when I wanted to slow the
airplane down that last mile an hour on landing. I didn't have any numerical
way to measure it, but it was clear that there was a small improvement. By the
time I hit the control stop with the yoke all the way back, the nose was a tad
higher.
Another trick that works in the Cessna is adding a small touch of power at the
last 2 or 3 seconds of the flare. This puts a little more prop blast on the elevator
and allows you to raise the nose another degree or two higher before "tail
stall" / "elevator stall" / "no more control authority". I have not done this
on a Kolb, but perhaps some Kolb pilots have tried this. I'd be interested
to see if a little prop blast solves or delays the loss of elevator authority
at the flare.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
Message 7
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| Subject: | Sun and Fun 2017 Canceled (for me) |
Hi Folks:
Got the airplane pushed out, topped off, and loaded. Come to find out my
Hawker Odyssey Battery I bought in 2006 or 2007 decided this morning it was
time to die. Started great last time I flew two days ago.
I have a new lithium battery jump start that I brought along today for its
first flight. Used it before we got off the ground. BTW, we didn't get off
the ground. Got it going, ran it 15 minutes while I finished loading. Shut
it down, got in and it failed to start. Called Bryan Melborn and canceled
out Lakeland this year. By the time I got a replacement it would have been
too late to fly today.
Thursday is doable, wind is out of the WNW, but there's lots of wind, plus
23 mph.
Looks like this will be the first S&F I have missed since my first in 1984.
Hopefully, there will be next year.
All the preparation didn't hurt a thing. I got the MKIII cleaned up, tuned
up, VG'd, and got me back into the swing of aviation again. I'll be ready
to fly West come next September.
john h
mkIII
Titus, Alabama
Message 8
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| Subject: | Re: VG's, tail stall, angle of attack |
Bill
With the high thrust line in our Kolbs I don't think adding power while
flaring is going to help you raise the nose. The normal advice is to
approach with a bit of power then cut the power to assist with flare.
As a side note, years ago when I was sorting out my VW I had a reduction
drive failure when I was at about 1,000 AGL. My normal landing procedure is
approaching with just a bit of power with one notch of flaps cutting power
after I settle in. I practiced ahead of time landing with no power with no
flaps and found the landing just about the same as some power with one
notch. So using what I had practiced I used my flaps like a negative
throttle to get me where I wanted to land then raised the flaps for
landing. No big deal. The added bonus was that nice landing spot turned out
to be a bean field and with no flaps I was able to get the tail down in the
beans first. The beans grabbed the tail wires like a carrier arresting
cable and I landed with no damage what so ever.
Rick Neilsen
Redrive VW powered MKIIIC
On Tue, Apr 4, 2017 at 1:22 PM, Bill Berle <victorbravo@sbcglobal.net>
wrote:
>
> What some folks might think of as a "tail stall" may just be air
> separating from the elevator itself. So the entire tail is not technically
> stalled, but if the air separates from the bottom of the elevator you would
> very likely see a reduction in control authority. So maybe "elevator stall"
> is the better way to describe it.
>
> The flat cross section tails (no airfoil) would likely be more prone to
> this, because the airflow forward of the hinge line is not as smooth or
> organized as it would be on a properly airfoiled tail. But as we know, tens
> of thousands of Cubs, Taylorcrafts, Aeroncas, Porterfields, and Kolbs are
> flying safely without an airfoiled tail. The "flat" tail is simply a
> compromise to make the airplanes easier and/or less costly to build. On a
> 70-90 MPH airplane it is an easy and worthwhile compromise to make.
>
> As a non-Kolb point of reference, I have an old Cessna 172 (1956, first
> year). Anyone with Cessna 172 time will verify that the airplanes are kind
> of nose-heavy with the rear seats empty, and that you basically "run out of
> elevator" when you are trying to do a minimum speed landing with one or two
> people in the front seats. What happens is that you feel the yoke (stick)
> hit the control stop, and you can't raise the nose any more, even though
> you can feel the airplane was willing to slow down a little more.
>
> But then I woke up one Christmas morning (in August), and in the middle of
> the night Santa Claus had installed little plastic VG's on the bottom of my
> horizontal stabilizer. As I was flying the aircraft directly to the
> Oklahoma City FAA office to report Santa for breaking the rules, I noticed
> that I was able to raise the nose of the Cessna just a little bit higher
> when I wanted to slow the airplane down that last mile an hour on landing.
> I didn't have any numerical way to measure it, but it was clear that there
> was a small improvement. By the time I hit the control stop with the yoke
> all the way back, the nose was a tad higher.
>
> Another trick that works in the Cessna is adding a small touch of power at
> the last 2 or 3 seconds of the flare. This puts a little more prop blast on
> the elevator and allows you to raise the nose another degree or two higher
> before "tail stall" / "elevator stall" / "no more control authority". I
> have not done this on a Kolb, but perhaps some Kolb pilots have tried this.
> I'd be interested to see if a little prop blast solves or delays the loss
> of elevator authority at the flare.
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and
> for-profit entities
>
>
Message 9
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| Subject: | VG's, tail stall, angle of attack |
Rick N/Kolbers:
It'll be alright. Miracles happen every day. The cataclysmic event to
follow was my dead battery. Not much of an event, but enough to change
my plans.
Yes, Richard P and I had a little slow flight competition between our
two birds. His with VGs and mine naked as a J-
Bird. Rick thinks we tied. Richard claims radio problems. What's that
got to do with slow flight? I think I beat him. We'll have to do it
again now that I have VGs.
Buford has some medical problems. Don't know what, but it is enough to
keep him off the List. Yes, I miss ole Buford too.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Rick Neilsen
Sent: Tuesday, April 04, 2017 10:12 AM
Subject: Re: Kolb-List: VG's, tail stall, angle of attack
=8BI'm shocked!!! John H has put VGs on his airplane! I'm
expecting some cataclysmic event to follow=8B!!!!
Years ago I witnessed and reported on the great VG fly off between John
and Richard Pike at a Kolb flyin. It should be in the archives so I
won't go back into the details here. But it was a tie.
I have some VGs on the sides of my fuselage at the wide point on my
doors and they do reduce the noise coming from the rear fuselage. I have
plans to someday put VGs on my wings and under my tail but it is a low
priority. I have a heavy engine and have put some major beef in the
passenger compartment including myself, I don't think anyone lapped but
I can't say that the old MKIIIC was ever less than capable of safely
committing flight.
Also I saw the post about missing Buford, has something happened to
him???
Rick Neilsen
Redrive VW Powered MKIIIC
Message 10
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Running a 3800 to 4000 creates a sufficient wind flow over the tail to
restore authority. As an energy management tool it will give you longer
time to find the runway, but also uses more runway. If you have runway to
spare, no problem.. if you are trying to get into a 700 ft strip at 4000
msl. You don't need to be leaving any runway behind you.
Boyd
Message 11
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| Subject: | Re: Sun and Fun 2017 Canceled (for me) |
I'm sorry to hear of your misfortune John. I'm sure they'll miss ya. I remou
nted my little 377 today on my Firestar 1. It's been sealed away since 1990.
It'll be ready start next week?
George H.
Firestar MK1, FS100
14GDH
gdhelton@gmail.com
Mesick, Michigan
Have a great day!
> On Apr 4, 2017, at 2:05 PM, John Hauck <jhauck@elmore.rr.com> wrote:
>
> Hi Folks:
>
> Got the airplane pushed out, topped off, and loaded. Come to find out my H
awker Odyssey Battery I bought in 2006 or 2007 decided this morning it was t
ime to die. Started great last time I flew two days ago.
>
> I have a new lithium battery jump start that I brought along today for its
first flight. Used it before we got off the ground. BTW, we didn't get of
f the ground. Got it going, ran it 15 minutes while I finished loading. Sh
ut it down, got in and it failed to start. Called Bryan Melborn and cancele
d out Lakeland this year. By the time I got a replacement it would have bee
n too late to fly today.
>
> Thursday is doable, wind is out of the WNW, but there's lots of wind, plus
23 mph.
>
> Looks like this will be the first S&F I have missed since my first in 1984
. Hopefully, there will be next year.
>
> All the preparation didn't hurt a thing. I got the MKIII cleaned up, tune
d up, VG'd, and got me back into the swing of aviation again. I'll be ready
to fly West come next September.
>
> john h
>
> mkIII
>
> Titus, Alabama
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