Bertie the Bunyip wrote:
E Z Peaces wrote in
:

Bertie the Bunyip wrote:
E Z Peaces wrote in
:

I've read about oleo aircraft struts at least as early as the 1920s.
Theyre not dampers, they're oleos and provide no damping. Shock
absorbers are something different and have a different function,
though tey're misnamed in any case, since its the springs that absorb
and the shicks, as they;'re called, prevent the energy stored in the
spring from rebounding the wheel off the road. Airplanes don't have
shock absorbers.
Here's an example:
http://www.hangar9aeroworks.com/Aero...oncastrut.html


Yeah, I know,. I was flying one a couple of days ago and I've had them
apart, too.
It does little or nothing to stop a bounce in spite of it's name. I can
also stater that categorically since I was training two ab-initio tailwheel
pilots in it.

Have you stood by the wing tip and rocked the wing like a seesaw? If
you can get it to rock higher and higher and it keeps rocking after you
let go, then I guess the landing gear doesn't have effective shock
absorbers.

I remember touchdown bounces from my days with balsa, tissue and dope.
None of my models would have bounced even slightly from a stationary
drop because all had rigid landing gear.

None had a movable elevator. I could climb and dive by changing thrust,
which would move the center of lift by slightly changing the speed. If
I wanted a plane to fly faster, I would move the center of gravity by
weighting the nose so the model would balance at a higher speed.

Without elevator control I couldn't make three-point landings. My
Curtis Hawk had the biggest bounce, but the airspeed was low enough that
it would rise only about five inches before mushing elegantly to the
ground. My Corsair would bounce about two inches.

My Spitfire landed much faster than the others because I weighted the
nose with two flashlight batteries. With that much airspeed, it might
have risen disastrously high if it had bounced on touchdown. It didn't
bounce at all.

The three models were different in the position of the main gear. The
wheels of the Hawk were well forward of the center of gravity;
apparently the Army plane was designed that way to counter the tendency
of a short, high plane to nose over when landing on a rough field at low
speed. When the wheels of my model touched down, the center of mass
would continue to fall, lowering the tail and increasing the angle of
attack. Naturally, it bounced.

The problem wasn't as bad with the Corsair because the wheels weren't so
far forward. The wheels of the Spitfire were farther back, and the
weights brought the center of gravity forward as well as increasing
inertia about the horizontal axis. This way, the tail didn't sink fast
enough for the plane to lift off after touchdown.

With my balsa models, bouncing came from the rapid sinking of the tail
after touchdown. If I'd had elevator control, I might have managed
three-point landings with the Hawk. I don't see how the model could
have bounced in that case. (A neighbor used to fly his father's
Stearman under his brother's instruction. He says he sometimes touched
down tail first.)