Close this search box.

Vought XF5U Flying Flapjack

A developed version of the original V-173 prototype, the XF5U-1 was a larger aircraft of all-metal construction, it was almost five times heavier, with two 1,400 hp (1,193 kW) Pratt & Whitney R-2000 radial engines.

A developed version of the original V-173 prototype, the XF5U-1 was a larger aircraft.

Of all-metal construction, it was almost five times heavier, with two 1,400 hp (1,193 kW) Pratt & Whitney R-2000 radial engines.

The configuration was designed to create a low aspect ratio aircraft with low take-off and landing speeds but high-top speed. 

The aircraft was designed to keep the low stall speed and high angle of attack from the V-173 prototype while providing for better pilot visibility, cockpit comfort, less vibration, and provisions to install armament.

This included a cockpit redesign moving the cockpit from the leading edge of the wing to a nose nacelle that extended further in front of the leading edge.

The arrestor hook was changed to a dorsal hook that would diminish the drag from the apparatus.

Normally, a wing with such a low aspect ratio will suffer from very poor performance due to the degree of induced drag created at the wingtips, as the higher-pressure air below spills around the wingtip to the lower-pressure region above.

In a conventional aircraft, these wingtip vortices carry a lot of energy with them and hence create drag.

The usual approach to reducing these vortices is to build a wing with a high aspect ratio, i.e., one that is long and narrow.

However, such wings compromise the manoeuvrability and roll rate of the aircraft or present a structural challenge in building them stiff enough.

The XF5U attempted to overcome the tip vortex problem using the propellers to actively cancel the drag-causing tip vortices.

The propellers are arranged to rotate in the opposite direction to the tip vortices, with the aim of retaining the higher-pressure air below the wing.

With this source of drag eliminated, the aircraft would fly with a much smaller wing area, and the small wing would yield high manoeuvrability with greater structural strength.

The propellers envisioned for the completed fighter unlike the torque-reducing counter-rotating propellers of the V-173 design were to have a built-in cyclic movement like a helicopter’s main rotor, with a very limited ability to shift their centre of lift up and down to aid the aircraft in manoeuvring.

Initially, the aircraft used propellers originally designed for the V-173 prototype.

These propellers would be replaced with propellers taken from the Vought F4U-4 Corsair.

An ejection seat was fitted to allow the pilot to clear the massive propellers in the event of an in-flight emergency.

Although the prototype was unarmed, a combination of six M2 Browning 50-caliber machine guns or four M3 20 mm cannons would be mounted in the wing roots in service.




28 ft 7 in (8.73 m)


32 ft 6 in (9.91 m)


14 ft 9 in (4.50 m)

Wing area

475 sq ft (44.2 m2)

Empty weight

13,107 lb (5,958 kg)

Gross weight

16,722 lb (7,600 kg)

Max take-off weight

18,772 lb (8,533 kg)


2 × Pratt & Whitney XR-2000-2 radial engine,

1,350 hp (1,007 kW) each


Maximum speed

452 mph (727 km/h, 393 kn) at 28,000 ft (8,534 m) (estimated)


710 mi (1,142 km, 620 nmi)

Service ceiling

34,500 ft (10,516 m)

Rate of climb

3,120 ft/min (15.8 m/s) or 914 m/min

Wing loading

39.2 lb/sq ft (191 kg/m2)


6 × .50 machine guns

2 × 1000 lb. bombs.



Share on facebook