deceleron

The aileron is also split, making it a deceleron.

A deceleron, or split aileron, was developed in the late 1940s by Northrop originally for use on the F-89 Scorpion fighter aircraft.

The deceleron is an aileron that functions normally in flight but can split in half such that the top half goes up as the bottom half goes down to brake.

The Intruder was also equipped with the "Deceleron", a type of airbrake on the wings with two panels that open in opposite directions; in this case, one panel goes up, while another goes down.