Question Statement:
A general aviation airplane is initially in steady and level flight. The stability
coefficient
𝜕Cm
𝜕q (Cm is the airplane pitching moment coefficient and q is the pitch
rate) is negative. The airplane is perturbed with a small nose-up constant pitch
rate. Assume that the horizontal tail does not stall during the perturbation, and
unsteady effects are neglected. When compared to steady and level flight
condition, which of the following statements is/are true during the perturbed
motion?
Options:
- (A) The angle of attack of the horizontal tail increases.
- (B) The contribution of the horizontal tail to the airplane's pitching moment about the center of gravity is more stabilizing.
- (C) The lift generated by the horizontal tail increases.
- (D) The contribution of the horizontal tail to the airplane's pitching moment about the center of gravity is less stabilizing.