Abstract: A body spoiler rotatably mounted within a recess formed within opposite sides of the forebody of a supersonic air vehicle and configured to conform with the fuselage of the vehicle. A sensor positioned close to the inlet of each engine powering the flight of the vehicle measures the pressure of the fluid entering the engine. If an engine on one side of the vehicle malfunctions, the pressure sensor sends a deploy signal to the body spoiler mounted on the same side of the vehicle. An actuator receives the deploy signal and rotates the spoiler through an angle which is dependent upon the speed of the vehicle. When deployed, the spoiler generates a shock wave which in turn produces pressure along the forebody thereby creating a yaw moment to substantially counterbalance the yaw moment generated by the malfunctioning engine.