Originally Posted by
Faileas
Thank you for the answers.
So generally, for an unpowered control system, in trim condition the elevator floats to a balance position and it is faired not with the rotated tailplane but with the local airflow, so that the force on the control column is relieved.
Is the misalignment relative to the adjustable horizontal stabilizer small?
Not always - depends on the position of balance/trim tabs, which are used to bias the elevator neutral position, in order to give the appropriate aircraft-level pitch balance.
I suppose that for maneuvering the stabilizer actuator is too slow and the elevator is used for this purpose, right?
Yes, Typical numbers are stabilizer rates of up to 0.5 deg/sec, which for 10-15 degrees stab range means 20-30 seconds to move the stab full range. Compared to typical elevator control speeds, which are of the order of full travel in 1 second, as a rule of thumb.
Obviously you'd never do either full travel change in flight, but it illustrates that the elevator is about 10x faster than the stab, so even though it's a less powerful control per degree of movement, you get better control from the elevator.
Of course, these numbers are for a THS+elevator aircraft. The stab rate for the all-flying-tail case is of course somewhat more sprightly.