wrote in message
...
On Tue, 21 Dec 2004 14:32:57 -0500, Corky Scott
wrote:


The reason for the failure, if I'm remembering this correctly, was
that the lower gears were not designed for continuous transmission of
power, at least not at the power levels required for flight. Whether
it was the width of the gears or the size of the bearings that
supported them, or even if there were bearings supporting the shaft, I
don't know. It could also have been a problem with prop loads on the
output shaft, not sure. But the transmission as a psru failed.

It could be the gears that failed, or it could be that the output
shaft could not stand up to the prop loads, don't know how George
supported the output shaft.

In any case, George should be congratulated for safely landing an
airplane with a decoupled prop that has one of the higher landing
speeds for light airplanes around. Putting down after a total loss of
thrust is never easy unless you practice frequently and even then you
always know it's just practice and a blown approach can be salvaged by
advancing power and trying again.

But the real thing is the real thing, and while some people flying
Long E-Z's manage to be at around 60 mph when touching down, most I've
heard of are faster than that to prevent the nose from pitching down
prematurely and uncontrollably.

Good job George.

Corky Scott

PS, I hope George posts here what failed in the transmission. It
would be illuminating.



What really beats on the gears, and what automotive use does not
experience, is the harmonics. Harmonics load the gears in BOTH
directions, with in the order of 10 times the steady state torque.

That tends to shear off teeth!!!

That's part of what I was also thinking, but there's mo

In the car or truck, the use of the clutch tends, over time, to randomize
the gear teeth in use at any specific parts of the power and compression
strokes. As I understand it, use of the same gear teeth all the time is a
common problem in spur gear transmissions. The problem is much worse if
applied to both gears--although that would be surprising in a jproduction
gearbox.

In addition, many people may omit all or part of the flywheel and clutch to
save weight. That could prevent the harmonic damper on the other end of the
engine from doing its job. And those little springs in the driven plate
should provide a lot of isolation once the engine is up to speed.

Finally, a lot of the support for the gears and bearings inside the
transmission is provided by the pilot bearing at the flywheel--especially on
rear wheel drive vehicles. A missing pilot bushing could place tremendous
bending loads on those little needle bearings between the input and main
shafts ...

Does anyone know which kind of transmission (transaxle or an in-line with a
straight through fourth gear) he was using, and what all failed in the
transmission besides the gear teeth?

Peter