The phenomenon known as wing drop is experienced by an air vehicle during maneuvers at moderate to high angles of attack (AoA). It is caused by an abrupt reduction of lift from one side of the vehicle prior to the other side. This sudden asymmetric loss of lift creates a rolling moment, which causes loss of control of the airplane's roll attitude. Though typically an abrupt and momentary loss of control, these disturbances may be quite severe (up to 60–90°), resulting in abandonment of the task being performed in order to regain control. In operations at low altitudes, even a momentary loss of roll control could result in the loss of the aircraft.