Deceleron

A deceleron is a type of aileron, developed in the late 1940s by Northrop originally for use on the F-89 Scorpion fighter aircraft. It is a two-part aileron that can be deflected as a unit to provide roll control, or split open to act as an air brake. Decelerons are also used in the Fairchild-Republic A-10 and the Northrop's B-2 Spirit bomber aircraft.