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Old January 17th 07, 02:43 PM posted to rec.aviation.homebuilt
jls
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Posts: 60
Default Can Washout Cause Flutter??


"cavelamb himself" wrote in message
link.net...
DonMorrisey wrote:
WERE (because it's probably a moot point now) the hinges and

alieron
actuation mechanism TIGHT (or maybe a little sloppy)?



Well, I actually never saw the airplane. My firiend says they

were
tight but who knows, he also didn't realize the bolts in the

brackets
were too far down from the bend in the spar flange, so I can't

really
say.

He was surprised that the aileron and nothing associated with it

had
any damage. That's what led him to his conclusion that the

washout had
something to do with it.

Don...


As another poster pointed out, we don't know anything about the

design
or construction of this plane.

But you _may_ have just answered your own question.

If the aileron brackets were supported by nothing more than the web

of
the rear spar I wouldn't be surprised it it encountered flutter.

It's an Aero-Elastic phenomenon, remember?

If it can flex, it fer sure will...

Glad nobody was hurt.


A wing being built here at the moment has three steel channel aileron
hinge brackets supported by the rear spar. They are attached to the
web by AN 5-5 bolts. They are also attached to the false spar,
though. That must make all the difference in the world.

Here's something interesting, to me anyways. C. G. Taylor did some
interesting things when he broke away from Bill Piper and tooled up
for the Taylorcraft. He made extensive use of magnesium alloy, in the
wheels, yokes, and aileron hinge brackets. It's light and strong, but
woe unto you when it starts to corrode.

On my Taylorcraft I noticed that the false spar was tight against the
hinge brackets. I should have looked more closely. When the aircraft
was built in the '40's, the false spar holes for the magnesium hinge
brackets were hand-cut, and some of them allowed the aluminum false sp
ar to rub up against the hinge brackets. From the constant faying one
of the magnesium brackets developed a crack over decades of use, and
one day it broke. I noticed the aileron response was mushy.

Thankfully a friend preflighted the aircraft before I flew it again.