After World War II, the US Navy was looking for ways to improve ship defense by equipping merchant ships with vertical take-off aircraft. A 1950 design competition selected Convair (#24) and Lockheed to each build a single-seat tail sitting fighter aircraft. Each used the Allison YT40-A-14 engine (two coupled T38 power sections mounted side-by-side) driving two 16 ft counter-rotating three-bladed Curtiss-Wright propellers with electric pitch control. The engines produced 5,500 eshp with a 7,100 eshp take-off rating, resulting in over 10,000 lb of thrust. The 37 ft fuselage had mid-mounted 30 ft span wings. Control in hover was by the same large aerodynamic surfaces as in level flight, as each was bathed in propeller slipstream; the "X"-shaped tail arrangement minimized downwash masking. An erector trolley was used to stand the XFV-1 in the vertical position; the tips of each tail had a small castoring wheel. The aircraft was fitted with a temporary conventional attitude landing gear and made its first horizontal flight in March 1954. A total of 27 conventional flights were made, with the first full transitions made above 1,000 ft that Fall. Control in hover was very weak, and the pilot had difficulty in determining sink, climb, and rotation from normal visual cues. No vertical take-offs or landings were ever attempted. As with the Convair XFY-1 Pogo, the engine and control systems were judged to be insufficient.