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Originally Posted by LivingInMEM
It is because you had a vert stab that was naturally dampening the yaw, the ailerons were used to dampen the roll.
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You obviously never flew the 727. With the Yaw Damper inop, one push of the rudder resulted in increasing deviations from neutral until you were rolling +or- 80 degress, and yawing back and forth far worse than your original rudder input.
Quote:
Originally Posted by LivingInMEM
If you had no vert stab, there would have been no (or a lot less) tendency for the nose to stop traveling in one direction and start traveling back to neutral.
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That's correct, there would be no (or a lot less) tendency for the nose to stop traveling. But again, you're talking about stability versus control. Yaw movements can be dampened with differential thrust. It's hard, but you can still control it. The airplane will not instantly become uncontrollable and crash.
Quote:
Originally Posted by LivingInMEM
By the way, stability is natural
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No it's not. Stability must be designed into all 3 axes.
Quote:
Originally Posted by LivingInMEM
control is what you provide
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That's correct.
Quote:
Originally Posted by LivingInMEM
without stability you lose control
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No you don't - without control...you lose control. Stability characteristics (both static and dynamic) are judged during flight testing. Some designs of the past turned out to have terrible stability during flight tests - and the aircraft returned to base to be tweaked by the engineers.
Quote:
Originally Posted by LivingInMEM
(ask any F-117 pilot especially what would happen to their control if they lost the computer provided their positive stability). Without one you don't have the other, you aren't that fast.
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Not just the F-117, but the F-16, F-22, etc. These aircraft were designed with extreme aft CG's so that they have extreme maneuverability. These specific aircraft will lose control because their Fly By Wire CONTROL systems are also what provides stability. When you lose your flight control system, you lose control. No argument there.
Carl