sentences:  Propeller control problems and gearbox failures were among the more common problems.The T40 was also fitted to the North American A2J-1 Super Savage but the poor performance of the aircraft and continuing difficulties with the engines forced cancellation in favour of the Douglas A3D Skywarrior.The most notable successes of the T40 were in the field of vertical take-off aircraft, being used to power three different types, the Convair XFY-1 Pogo, Lockheed XFV-1 and the Hiller X-18 tilt-wing research aircraft.