The Vought F6U Pirate was the Vought company’s first jet fighter, designed for the United States Navy during the mid-1940s.
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.
None were ever issued to operational squadrons, and they were relegated to development, training, and test roles before they were withdrawn from service in 1950.
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.
Chance Vought was awarded a contract for three V-340 (company designation) prototypes on 29 December 1944.
The XF6U was a small aircraft with tricycle undercarriage and with straight wings and tail surfaces.
The wings were short enough that they did not need to fold.
To fit more aircraft into crowded hangars, the nose gear could be retracted, and the aircraft’s weight would rest on a small wheel attached by the ground crew.
This raised the tail up so that it could overlap the nose of the aircraft behind it, allowing more aircraft to fit into available hangar space.
The turbojet engine was mounted in the rear fuselage and was fed by ducts in each wing root.
The most unusual feature of the aircraft was its use of “Metalite” for its skin.
This was made of balsa, sandwiched between two thin sheets of aluminium. “Fabrilite” was also used for the surfaces of the vertical stabilizer and rudder; this was similar to Metalite but used fiberglass instead of aluminium.
Two fuel tanks were fitted in the centre of the fuselage; the forward tank, ahead of the wing, contained 220 US gallons (830 l; 180 imp gal) and the rear tank, 150 US gallons (570 l; 120 imp gal).
These were supplemented by two jettisonable 140-US-gallon (530 l: 120 imp gal) tip tanks.
The cockpit was well forward and was provided with a bubble canopy which gave the pilot good visibility.
He was provided with a Mk 6 lead-computing gyro gunsight.
Underneath the cockpit were four 20 mm (0.79 in) M3 autocannon.
Their 600 rounds of ammunition were carried behind the pilot.
The empty casings of the two upper guns were retained in the aircraft, while those from the two lower guns were ejected overboard.
After a company-wide contest to name the aircraft, the initial prototype received the name Pirate and made its first flight on 2 October 1946.
Flight testing revealed severe aerodynamic problems, mostly caused by the airfoil section and thickness of the wing.
The vertical stabilizer also had to be redesigned to smooth out the airflow at the intersection of the horizontal and vertical stabilizers.
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.
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.
Three prototypes, two with a Westinghouse J34-WE-22 turbojet engine, one with a J34-WE-30 with afterburner.
Afterburner-equipped production version, 30 built, 35 cancelled.