Today's Message Index:
----------------------
1. 04:50 AM - Re: Ailerons (K Dilks)
2. 05:51 AM - Re: Ailerons (Dave Austin)
3. 12:26 PM - Re: Re: Ailerons (Dave)
4. 03:20 PM - Re: Ailerons (Sabrina)
5. 04:55 PM - Re: Ailerons ()
6. 07:01 PM - HOmeland security crap buggering GA (ashontz)
7. 07:17 PM - Re: HOmeland security crap buggering GA (Sabrina)
8. 07:25 PM - Re: HOmeland security crap buggering GA (ashontz)
9. 07:36 PM - Re: HOmeland security crap buggering GA (Mike Moore)
Message 1
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OK this is how I see this.
The real issue weather an aileron needs balancing is the design speed and the
design of the aileron its self.
Low speed plane ( below 100mph) can getaway without either dynamic ( balance weights)
nor aerodynamic balance. These designs have a hinge at the very front
of the aileron(XL style)
Next up the speed ladder is no dynamic balancing but with the hinge point offset
so as to act with some aerodynamic balance( plus a small mass balance due to
the mass foward of the hinge line.
After this is the full mass balance ( but not necessary 100% of aileron mass )
with carefully positioned hinge points to give more aerodynamic balance.IE look
at a fully aerobatic aileron, some having spades to give more aerodynamic balance.
Last is hydraulic assistance etc etc
One thing that strikes me is that even if the cable tension is correct they
then presume that the blob in the cock pit is holding the stick tight.
Tight control cables do not cure a potential flutter issue, they just delay its
onset at best. The issue is what actually causes the flutter in the first place
and this is corrected by the correct engineering of mass balance, aerodynamic
balance and the aileron hinge point. Obviously profile shape will enter
the equation but this is the basics.
I am not saying that for sure the XL needs balanced controles but as they would
eliminate a potential serious problem and possible make for nice controle
harmony why not fit them? In the UK there attitude I feel is correct if they have
found a resonable chance of flutter occuring then somthning should be done.
Normally aircraft are over engineered in aspects like this to give a reasonable
saftey factor but this seems marginal at best on the XL.
Sorry for my monolog but had to air my thoughts
Kev Brit living Austria ....FAA A+P
--------
Austria .............
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=235210#235210
Message 2
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Has anybody done any work on the size of the mass balancer? From
previous building I'm aware that it does not have to be fully balanced
to get enough benefit to prevent flutter. There has to be a graph of
"percent of aileron weight" to "flutter inhibiting ability" somewhere.
Dave Austin 601HDS - 912
Message 3
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While I fully endorse the notion of pilots of "experimental" aircraft trying
to design/discuss/improve their aircraft, most of these discussed solutions
appear to assume that somebody actually knows that 1) there actually is a
problem, and 2) the ailerons are the source of said problem. I'm not any
more sure of that than I am of the assertion by the faithful that "There
absolutely cannot be any problem because the design hath been decreed from
on high by CH". Now if the discussion were to centered more on the idea
that: "Balanced ailerons have been shown to be a good idea in general. Lets
find a good way to apply that idea and improve our aircraft." it would look
better. Because at the end of the day nobody here has any data that this is
THE solution to the question of why do bad things appear to be happening.
Do Not Archive
Message 4
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In light of Terry's comments and my response, many have written off line asking
me if I think aileron flutter is THE problem. NO ONE KNOWS at this point, and
even if it is A problem, it might be overspeed plus some trigger that is the
real problem, not the design.
I don't know what is tearing the wings off anymore now that I did in 2006. Terry
and ZBAG are onto a scent and I hope they figure it out.
What kept coming to my mind was the Tacoma Narrows Bridge.
http://www.youtube.com/watch?v=NjT56h6Ez3Q
Looking at the design and examining XLs in 2005 and 2006 and while building I came
to the personal opinion that MY fuselage could not dampen vibrations well
enough without more.
I don't like how the rear spar attach plates are not very well cross-tied. I don't
like how wide the fuselage is and how the main spar is tied to the skins/cabin
floor.
I decided to reinforced the rear fuselage with a thermoplastic/foam/aluminum shoe
from 6B5-6 to 6B5-6 encasing 6B21-1 & 6B21-2 and including most of the area
under 6B21-7.
I also decided to reinforced the main spar and forward fuselage with a "tub" of
aluminum/foam/aluminum&thermoplastic including the forward side skins, L angles,
main spar uprights, firewall, cabin floor, forward top skin, etc. So too,
I added additional lateral stiffening (foot rest) as well as main spar to firewall
stiffeners and spar to cabin floor stiffeners. My cabin floor is 1 5/8"
higher than most and the "twin" forward top fuselage skin is nearly 1 3/4 inches
lower than the original. So too, the firewall is two inches thick in many
places, as are the cabin sides from the firewall to just past the the main spar
uprights.
I have an indicator that will hopefully pop up if the center section of the main
spar moves relative to the forward fuselage and two additional indicators that
will pop loose if the main spar uprights twist beyond nominal.
In case my engine could "trigger" any oscillations, I created and installed an
engine dampener that looks like a horseshoe.
My biggest fear now is/are the heavy Ray Allen pistol grips I have sitting atop
two sticks. I have tried to dampen them with leather and thermoplastic the best
I could.
It appears to take speed, plus a trigger plus a fuselage that will not dampen before
a wing will come off.
So the short answer--do I think mass balanced ailerons are the only cure: NO.
Will I tension my aileron cables and keep to speeds under what the 3D computer
models suggest as to Vne: YOU BET.
We are concentrating TOO much on the LAA aileron mandates and NOT enough on their
mandates on how to strengthen the center section of the main spar. I would
suggest to those that have written me off line to seriously consider the LAA
recommendations and the ones on strengthening the fuselage/main spar center section
in particular.
Your guess is as good as mine. :o)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=235282#235282
Message 5
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About a week ago I dropped in at my friendly Airparts, and looked
through their stock, thinking in terms of pushpull tubes for my
ailerons. I pulled out some tubes ranging from 1-1/4 down to 3/4, and
then looked at SQUARE tubing as well. Pullin almost 12 feet of tube out
of the racks, none of them were particularly easy to bend by hand, and,
at the roughly 7 feet from bellcrank to fuselage skin, not of them had
any appreciable sag. I suppose there might be some harmonics in a piece
that long, but I very seriously doubt you'd get a tube to bend under
aileron pressure until very near mach one - in which case you then have
a very different concern. So, the plan is-- one length of pushpull rod
from bellcrank to fuselage skin, a 6 to 8 inch inner splice held by a
couple of AN=3 bolts, and an approx 21 inch tube from control stick to
the other end of the inner splice. And, if I can lay hands on the
appropriate size aluminum bar, and well-centered drilled and tapped
holes in the bar, threadad ball rod ends to allow for adjustment, with
locknuts to keep them that way. (And, square tubing even looks cool.)
Paul Rodriguez
----- Original Message -----
From: ZodieRocket<mailto:zodierocket@hsfx.ca>
To: zenith-list@matronics.com<mailto:zenith-list@matronics.com>
Sent: Wednesday, March 18, 2009 6:35 AM
Subject: RE: Zenith-List: Ailerons
Problem is that in the XL the span for a push rod is quite large and
you have travel in a vertical as well as a horizontal range. With such a
run, to make a system that can handle the load that the cables are
capable of you would need to have a complicated bearing arrangement to
support the push rod in both movements. I imagine that the system can be
done safely with a complete change in which the way the controls
presently work, but just adding a rod with a few fittings would not be
able to handle the design loads that the cables can handle for a safe
conversion.
Mark Townsend Alma, Ontario
Zodiac CH650 C-GOXL, CH701 Rotax 912,
STOL CH750 Just started
www.ch601.org<http://www.ch601.org/> /
www.ch701.com<http://www.ch701.com/>/
www.Osprey2.com<http://www.osprey2.com/>
-----Original Message-----
From: owner-zenith-list-server@matronics.com
[mailto:owner-zenith-list-server@matronics.com] On Behalf Of Roger &
Lina Hill
Sent: Tuesday, March 17, 2009 12:12 PM
To: zenith-list@matronics.com
Subject: RE: Zenith-List: Ailerons
Well I have to wonder, why not just use Push rods instead of cables
for the Ailerons? Then you never have to worry about cable slack.
I have them on my HDS 601 and they work perfectly.
Roger
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From: owner-zenith-list-server@matronics.com
[mailto:owner-zenith-list-server@matronics.com] On Behalf Of
Jeyoung65@aol.com
Sent: Tuesday, March 17, 2009 10:31 AM
To: zenith-list@matronics.com
Subject: Re: Zenith-List: Ailerons
My understanding of control surface flutter is it can be caused by
control surfaces than can move without input forces. If they move upward
due to ruff air they will then be forced downward due to the air load on
them. They are then forced up ect until an input force is applied to
stop the cycle. So be sure to check your cable tension and looseness of
all connection. Jerry of Ga
In a message dated 3/17/2009 8:47:21 A.M. Eastern Standard Time,
bill_dom@yahoo.com writes:
The way I understand it is that cable tension does work in
preventing flutter, but relying in cable tension alone is not acceptable
by the FAA because of the possibility of cable loosening up. This could
be very critical if cables loosen up during the course of one flight, as
already happened to a 601XL.
As I say, this is the way I understand it. Meaning, I could be
wrong and and would like to be clarified.
William Dominguez
Zodiac 601XL Plans
Miami Florida
http://www.geocities.com/bill_dom
--- On Tue, 3/17/09, roger lambert <n601ap@gmail.com> wrote:
From: roger lambert <n601ap@gmail.com>
Subject: Zenith-List: Ailerons
To: "zenith-list@matronics.com" <zenith-list@matronics.com>
Date: Tuesday, March 17, 2009, 8:38 AM
It has been stated:
Just because cable tension is not an acceptable
means of preventing flutter in certified aircraft, does
not mean that
it does not work.
It should be noted that many certificated aircraft, including
those flying in Great Britain, have ailerons wihout external mass
balanced ailerons. These include Piper Cubs, Aeroncas and, I believe,
Grumman Cheetahs and Tigers.
It also should be noted that in no crash/incident reported to
date did the aileron cables fail, only that owners failed to maintain
the cable tension.
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Message 6
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| Subject: | HOmeland security crap buggering GA |
So is that it, our lives (at least building and flying are a life passion of mine)
just come to a screeching halt now because an airliner was used as a weapon
8 years ago? Check the latest edition of e-hotline. They're getting close to
making sure we're nothing but a nation of losers that sit around and watch reality
tv.
What if the goobermint proposed this type of intrusive lock down on how people
operate their cars, or their sex lives, or had to swipe everytime they entered
and exited their homes etc... At what point are people going to finally get effectively
outraged at this sh!t?
--------
Andy Shontz
do not archive
CH601XL - Corvair
www.mykitlog.com/ashontz
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=235316#235316
Message 7
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| Subject: | Re: HOmeland security crap buggering GA |
We need to show them the value of general aviation...
Here is just one idea:
http://www.youtube.com/watch?v=bzI1b_nfAu8&feature=channel_page
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=235317#235317
Message 8
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| Subject: | Re: HOmeland security crap buggering GA |
shouldn't have to prove the value of anything, it's just what some people do to
have fun.
The things that need to be valued and respected by these people are American's
rights (not privileges), right to life, liberty, and the pursuit of happiness.
Where these control freak communists come off thinking they have to right to
regulate everyone's life is beyond me.
--------
Andy Shontz
do not archive
CH601XL - Corvair
www.mykitlog.com/ashontz
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=235318#235318
Message 9
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| Subject: | Re: HOmeland security crap buggering GA |
Hi Andy,
-
Better be careful, or the FAA may come after you for exhibiting unstable, a
ntisocial (ist) behavior. After all, everything that our government (Can yo
u believe the freedom-loving American electorate actually voted them into p
ower, err.. office?) is doing is for the betterment of the majority of Amer
icans who earn less than - whatever the number is this week.
-
These certainly are interesting, and dangerous, times that we live in...
-
M2
-
Please don't archive, as I know it's off topic and I don't want to leave a
trail. Oops, too late; the IRS/congress is already at the door.
-
--- On Thu, 3/19/09, ashontz <ashontz@nbme.org> wrote:
From: ashontz <ashontz@nbme.org>
Subject: Zenith-List: HOmeland security crap buggering GA
<ashontz@nbme.org>
So is that it, our lives (at least building and flying are a life passion o
f
mine) just come to a screeching halt now because an airliner was used as a
weapon 8 years ago? Check the latest edition of e-hotline. They're getting
close to making sure we're nothing but a nation of losers that sit around
and watch reality tv.
What if the goobermint proposed this type of intrusive lock down on how peo
ple
operate their cars, or their sex lives, or had to swipe everytime they ente
red
and exited their homes etc... At what point are people going to finally get
effectively outraged at this sh!t?
--------
Andy Shontz
do not archive
CH601XL - Corvair
www.mykitlog.com/ashontz
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=235316#235316
=0A=0A=0A
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