777: Where is the yaw damper switch?!

[JSACKS 0]

I know the Yaw Dampers are active with the AP switched on. My question is: where are the yaw damper switches in this model?!JS

[ubersu 78]

There aren't any... I'd have to do some checking, but I believe that the T7 doesn't have any -- it is a highly automated aircraft.DJ

[JSACKS 0]

This is odd because on prior threads that I've searched it appears that there is a possibility of turning the YD on or off in the sim model. And yet I believe it is engaged automatically when the AP is engaged, perhaps as part of the generally computerized automation of flight control surfaces (?). I've checked out shots of the overhead on the real T-7 as well and saw no YD switches. This seems weird to me because I thought that even if the AP is engaged you should still be able to kick the rudder pedals if necessary and get some authority over the rudder. But maybe not in the T-7?JS

[ubersu 78]

On modern computerized a/c the yaw damping and rudder authority is governed by the flight control laws as a function of speed. At low speeds no damping is needed and at high speeds the a/c may be unflyable without it. The Vulcan, for example, used active yaw and pitch damping that kicked in approaching the Mach since it was unstable in both yaw and pitch above Mach .9 or thereabouts. Rudder travel is limited as speed increases and may be almost non-existant at cruise. Even at lower speeds one has to be careful as evidenced by the unfortunate crash of flight 587 on Long Island -- in that case kicking the pedal resulted in the complete failure of the vertical stabilizer. The T7 overhead panel is much simpler than earlier Boeings because of automation. I suspect the MD11 may not have switches either, since virtually all functions are computerized on that plane.DJ

[JSACKS 0]

Thanks, DJ, appreciate the post.JS