Design an autopilot system to control an aircraft's altitude.

Substituting the given values, we get:

-0.2 > 0 (not satisfied)

Therefore, the aircraft is longitudinally stable.

where n is the yawing moment.

For lateral stability, the following condition must be satisfied:

Cnβ = ∂n / ∂β

Gc(s) = Kp + Ki / s + Kd s