locked-in stall

deep stall

A condition associated with the T-tail configuration, in which there is a rapid increase in the angle of attack to an extent that the horizontal tail is unable to provide sufficient longitudinal control. Also called a locked-in stall.

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superstall

A stalled condition in which there is a progressive decay in speed along with an increase in the angle of attack and in which the aircraft descends in an approximately level or slightly nose-up attitude. The recovery action is to decrease the load factor and push the control column forward. This condition can also happen if the horizontal tail immerses in a wing wake, such as in a T-tail aircraft, making the situation worse. If the aircraft cannot be recovered, then the condition is known as a locked-in stall.

An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved