Plain English Meaning

If something bumps the aircraft off its path, the wobble gets bigger and bigger instead of settling down. The pilot has to step in to stop it.

Full Definition

A condition in which an aircraft, once disturbed from its trimmed flight path, develops oscillations or motions that grow larger over time rather than damping out. The aircraft moves further away from its original state with each cycle and will not return to steady flight without pilot intervention.

Context Anchor

Seen in basic aerodynamics and aircraft stability discussions, especially when describing how an airplane responds after a , bump, or input.