Physical strength of legs for rudder.

[misd-agin]

Originally Posted by Loose rivets

On the medical forum, I was talking about strength of knees needed in modern transport aircraft, I guessed at 100-150lbs. Is there a stated figure for the physical power needed in failure configurations?


http://www.pprune.org/forums/showthr...=1#post2755671

From the AA 587 crash various rudder forces were published. I believe the highest rudder force was about 80 lbs(?). I think all the newer Boeing products use that.

Typically the first 22-25 lbs of rudder push does absolutely nothing. It's designed that way to avoid having accidental inputs when a lesser force is applied.

(A300)Below 165 kts(?) full rudder travel force was 66 lbs. At the accident speed (250 kts and still accelerating) full rudder force was 33 lbs, or 11 lbs above 'breakout' force.

Rudder travel below 165 kts was 3.8 inches. At accident speed was 1.3(?) inches.

Older jets (737/DC-9s/S-80's/727/707, etc) had this type of rudder design.

Newer Boeing products (747/757/767/777) keep a constant force and rudder travel requirement. IE 4 inches and 80 (?) lbs, at any speed gives you 100% of available rudder travel. But at higher speeds the rudder travel is restricted to avoid over controlling, and/or damaging the a/c.

I'm not aware of the medical standards but a friend returning from SEVERE pelvis/leg injuries (shattered from waist down...) had to fly a complete single engine pattern without using any rudder trim. First attempt wasn't successful. A month later he was strong enough to pass.