-0.2 > 0 (not satisfied)

An aircraft has a lateral stability derivative of -0.1 and a directional stability derivative of -0.2. Determine the aircraft's lateral and directional stability.

-0.1 < 0

Cnβ = ∂n / ∂β

Substituting the given values, we get:

Therefore, the aircraft is longitudinally stable.

∂n / ∂β > 0