The 707 had a boosted rudder (hydraulic system).
Full 3000 psi was available when flaps were 14 and speed was low.
At higher speed, and flaps up, the boost pressure reduced to 750 psi...
Hope my numbers are correct, my last flight on 707 was 20+ years ago.
Thanks, but what is rudder boost really there for?
I always thought that the rudder performance was limited by airspeed, fin area and fin deflection. If the airspeed is low (AWACs accident) then it shouldn't take unusual pedal pressure to fully deflect it??? or am I all screwed up