Today's Message Index:
----------------------
1. 05:36 AM - Re: Aileron flutter (Thom Riddle)
2. 01:37 PM - Re: Aileron flutter and Tail-wag (Beauford)
3. 02:01 PM - Aileron flutter and tail-wag (Lanny Fetterman)
4. 02:27 PM - Re: Re: Aileron flutter and Tail-wag (John Hauck)
5. 02:27 PM - Re: Re: Aileron flutter and Tail-wag (zeprep251@aol.com)
6. 03:02 PM - Re: Aileron flutter and Tail-wag (Ralph B)
7. 03:29 PM - Re: kolb stall (Ralph B)
8. 05:10 PM - Re: Re: Aileron flutter and Tail-wag (Beauford)
Message 1
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| Subject: | Re: Aileron flutter |
Richard,
"Slow cars and sad music". what a wonderfully clear way to make a point!
do not archive
--------
Thom Riddle
Buffalo, NY (9G0)
Kolb Slingshot SS-021
Jabiru 2200A #1574
Tennessee Prop 64x32
Everyone is entitled to his own opinion, but not his own facts.
Daniel Patrick Moynihan
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313575#313575
Message 2
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| Subject: | Re: Aileron flutter and Tail-wag |
Brother Pike:
The Kolb rudder oscillation- tail wag phenomenon has been mentioned on the
list several times in the past... True to form, take my tootsies off the
pedals for five seconds or so, and the Kleenex Machine will invariably
launch into an increasing amplitude snake dance.
Since Beauford is not into self abuse (beyond matrimony) and I have a strong
recollection of how few lil' ol pop-rivets are holding the arse end of the
thing in association with the front end, I never let it go more than three
or four seconds before putting the feet back on the pedals to stop it before
it gets really wild.
In my aerodynamic ignorance, have always assumed this to be some combination
of rudder mass balance issue and interaction with the propwash vortex.
Since it is easily arrested and Kolbs have no history of shedding tails or
boom failure, have never been overly concerned about it...but am curious as
to whether any of the learned brethren on the List know exactly why this
happens to Kolbs and what practical fix might solve it without a redesign of
the vertical tail surfaces...
Anybody?
Or from another angle... Does anyone have a Kolb that does NOT exhibit this
behavior...?
Curious Beauford
FF-076, N173BW
Brandon, FL
Then there was the matter of the rudder flutter, take your feet off the
rudder pedals and they would start to shuffle and the tail would start to
wig-wag..
Richard Pike
MKIII N420P (420ldPoops)
Message 3
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| Subject: | Aileron flutter and tail-wag |
My FSII kit came with the aileron counter weights, so I have never
experienced that flutter problem. I don`t fly with my feet completely
off the rudder peddles, but I do fly with very little pressure on
them. I have never felt them start to flutter. I fly around 60 mph
according to the GPS. Perhaps that isn`t fast enough to induce
flutter. Flutterless is good, so I`ll leave everything as it is. Lanny N598LF
Message 4
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| Subject: | Re: Aileron flutter and Tail-wag |
> In my aerodynamic ignorance, have always assumed this to be some
combination
> of rudder mass balance issue and interaction with the propwash vortex.
>what practical fix might solve it without a redesign of
> the vertical tail surfaces...
> Or from another angle... Does anyone have a Kolb that does NOT exhibit
> this
> behavior...?
>
> Curious Beauford
Beauford/Gang:
That is also my assumption.
My initial fix was heavy feet.
I finally came up with a bright idea, double rudder pedal springs applied
about the same pressure as heavy feet. Works great, can fly with feet on
the deck and no tail wag.
I have flown a couple Kolbs that did not tail wag, however, I think it is a
Kolb characteristic that no one, that I know of, has died of.
Anybody know of a Kolb that crashed because of tail wag???
john h
mkIII
7 miles south of Burns Junction, OR
Message 5
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| Subject: | Re: Aileron flutter and Tail-wag |
Beauford,
My MK-3 will do the wag in it's normal configuration,but adding a second
set of springs to the rudder cables has all but eliminated it.Brother Pik
e is the only Kolbster, ( that I know of), that has treated his aircraft
with a counter balance and solved the issue.But he now has to deal with
birds perching on the balance rod and crapping on the boom tube.A small
price to pay for aerodynamic bliss.
G.Aman Mk-3 C Jabiru 2200A 590 hrs.
-----Original Message-----
From: Beauford <beauford173@verizon.net>
Sent: Fri, Sep 24, 2010 4:29 pm
Subject: Kolb-List: Re: Aileron flutter and Tail-wag
Brother Pike:
The Kolb rudder oscillation- tail wag phenomenon has been mentioned on the
list several times in the past... True to form, take my tootsies off the
pedals for five seconds or so, and the Kleenex Machine will invariably
launch into an increasing amplitude snake dance.
Since Beauford is not into self abuse (beyond matrimony) and I have a stro
ng
recollection of how few lil' ol pop-rivets are holding the arse end of the
thing in association with the front end, I never let it go more than thre
e
or four seconds before putting the feet back on the pedals to stop it befo
re
it gets really wild.
In my aerodynamic ignorance, have always assumed this to be some combinati
on
of rudder mass balance issue and interaction with the propwash vortex.
Since it is easily arrested and Kolbs have no history of shedding tails or
boom failure, have never been overly concerned about it...but am curious
as
to whether any of the learned brethren on the List know exactly why this
happens to Kolbs and what practical fix might solve it without a redesign
of
the vertical tail surfaces...
Anybody?
Or from another angle... Does anyone have a Kolb that does NOT exhibit thi
s
behavior...?
Curious Beauford
FF-076, N173BW
Brandon, FL
Then there was the matter of the rudder flutter, take your feet off the
rudder pedals and they would start to shuffle and the tail would start to
wig-wag..
Richard Pike
MKIII N420P (420ldPoops)
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Message 6
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| Subject: | Re: Aileron flutter and Tail-wag |
My Firestar will do the tail wag with the feet off the rudder pedals only if hit
by a strong thermal. Otherwise there is none. I can make it quit by bringing
it up into a stall. The Kolbra does not have this problem.
Ralph
--------
Ralph B
Original Firestar 447
N91493 E-AB
1000 hours
23 years flying it
Kolbra 912UL
N20386
2 years flying it
120 hrs
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313655#313655
Message 7
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> That "nasty" Kolb stall is due to wing loading. My Firestar has a gentle stall
with 148 sq feet of wing. Take that same wing and double the wing loading like
the Kolbra, and it can be a killer if you're not careful. When I was transitioning
to the Kolbra, I would ask Mark why it wanted to drop as we were landing.
I told him that my Firestar didn't do that. He couldn't give me an answer
because that was the only Kolb he has flown. To keep from dropping the wing,
I stay well away from stall. It scares me to slow it up on landing, and for good
reason. On the other hand, if I do a power on stall at altitude, it refuses
to drop because of the VG's.
>
> Ralph
I made a discovery since this last post. I have always landed the Kolbra solo without
using the flaperons because this was the way Mark recommended it and I've
always landed it hot, so it wouldn't drop. It's been awhile since I had the
chance to fly solo, so this past Wednesday I decided to put the flaperons down
on landing. I purposely slowed it up to see if it would drop. Would you believe
it landed pretty much like the Firestar where the tailwheel hit first and
the mains came down ever so softly? I was surprised and happy to see this. One
would think that I would have experimented with this a long time ago, but I'm
a person of habit and if I'm trained to do it one way, I keep doing it that way.
Now, I also have to say the flaperons on the Kolbra don't go down too far,
but enough to change the center of lift on the wing and eliminate the drop while
flaring.
Ralph
--------
Ralph B
Original Firestar 447
N91493 E-AB
1000 hours
23 years flying it
Kolbra 912UL
N20386
2 years flying it
120 hrs
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=313660#313660
Message 8
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| Subject: | Re: Aileron flutter and Tail-wag |
John:
Already have the double springs installed, Sir.... not for the wag, but just
because of a general distrust
of springs in general...tail wags anyway...
Most things I mess with either suffer from abrupt unanticipated drop or
directional instability...
So this is no big deal... But would still like to see a picture of the
Reverend Mr. Pike's counterweight
contrivance fer rudders... Are ye out there, Richard?
Do not archive
Beauford
FF-076
Brandon, FL
--------------------------
I finally came up with a bright idea, double rudder pedal springs applied
about the same pressure as heavy feet. Works great, can fly with feet on
the deck and no tail wag.
john h
mkIII
7 miles south of Burns Junction, OR
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