 The first XF6U-1 prototype was powered by a Westinghouse J34-WE-22 turbojet with 3,000 lbf (13.34 kN) thrust, one third of the weight of the aircraft. To help improve the underpowered aircraft's performance, the third prototype, which first flew on 10 November 1947, was lengthened by 8 feet (2.4 m) to use a Westinghouse J34-WE-30 afterburning engine of 4,224 lbf (18.78 kN) thrust, the first United States Navy fighter to have such a powerplant.
