Therefore, the aircraft is directionally unstable.
The static margin (SM) is given by:
Substituting the given values, we get:
∂m / ∂α < 0
Altitude Sensor → Controller → Actuator → Aircraft → Altitude Sensor Flight Stability And Automatic Control Nelson Solutions
For directional stability, the following condition must be satisfied:
where n is the yawing moment.
-0.2 > 0 (not satisfied)