Factors which affect longitudinal stability of aircraft
Answers
An aircraft's stability is expressed in relation to each axis: lateral stability – stability in roll, directional stability – stability in yaw and longitudinal stability – stability in pitch. The latter is the most important stability characteristic.
The longitudinal stability of an aircraft refers to the aircraft's stability in the pitching plane - the plane which describes the position of the aircraft's nose in relation to its tail and the horizon.[1] (Other stability modes are directional stability and lateral stability.)
If an aircraft is longitudinally stable, a small increase in angle of attack will cause the pitching moment on the aircraft to change so that the angle of attack decreases. Similarly, a small decrease in angle of attack will cause the pitching moment to change so that the angle of attack increases.