Although pioneering the use of turbojet power as the first naval fighter with an afterburner and composite material construction, the aircraft proved to be underpowered and was judged unsuitable for combat.

A specification was issued by the Navy's Bureau of Aeronautics (BuAer) for a single-seat, carrier-based fighter powered by a Westinghouse 24C (later J34) axial turbojet on 5 September 1944.

Flight testing revealed severe aerodynamic problems, mostly caused by the airfoil section and thickness of the wing.

Other changes included the addition of dive brakes on the sides of the fuselage and the replacement of the Metalite panels near the engine exhaust with stainless steel ones.

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[5] afterburning engine of 4,224 lbf (18.78 kN) thrust, the first United States Navy fighter to have such a powerplant.

The aircraft had to be disassembled and trucked to an abandoned airfield at Ardmore, Oklahoma, with a runway long enough for acceptance testing.

[8] The first production F6U-1 performed its initial flight on 29 June 1949, and 20 of the aircraft were provided to VX-3, an operational evaluation squadron based at Naval Air Station Patuxent River in Maryland.

[11] On 30 October 1950, BuAer informed Vought of the Navy's opinion of the Pirate in terms both bureaucratic and scathing: "The F6U-1 had proven so sub-marginal in performance that combat utilization is not feasible.

"[12] The aircraft ended up being used primarily to develop arresting gear and barriers, but were used operationally for a short time by at least one Texas-based United States Naval Reserve squadron as they transferred to jets.