Title: Define longitudinal stability.
Course: Aircraft Pilot Training I (20053-I) > Section: Examining the Forces that Act on Aircraft

Definition should include the concept that longitudinal stability is the quality that makes an airplane stable about its lateral axis. It involves the pitching motion as the airplane’s nose moves up and down in flight.

A longitudinally unstable airplane has a tendency to dive or climb progressively into a very steep dive or climb, or even a stall. Thus, an airplane with longitudinal instability becomes difficult and sometimes dangerous to fly.