longitudinal stability

longitudinal stability

[‚län·jə′tüd·ən·əl stə′bil·əd·ē] (engineering) The ability of a ship or aircraft to recover a horizontal position after a vertical motion of its ends about a horizontal axis perpendicular to the centerline.

longitudinal stability

The stability of an airplane about the lateral (pitching) axis. An airplane is stable if, when its angle of attack is temporarily increased, forces act in such a way as to push the nose down and thus decrease the angle of attack. The main factors that affect longitudinal stability are the design of the tailplane and the position of the center of gravity. The tail design features that may affect the restoring moment or longitudinal stability are the total tailplane area, the length of the moment arm, its plan form, and the downwash angle from the wing. The position of the center of gravity affects the ratio of the tail moment and therefore the degree of stability.