Curtiss 99 / XF15C
US Navy interest in the mixed-power concept for shipboard fighters had resulted in orders for three prototypes of the Ryan XFR-1, and 100 production FR-1s.
Taken a stage further, on 7 April 1944 a contract for three prototypes of the more powerful XF15C-1 was placed with Curtiss. This was to be powered by a 2,100hp Pratt & Whitney R-2800-34W 18-cylinder two row radial in the front with a four-bladed propeller and a 1226kgp Allison-Chalmers J36 (Halford H-1B) turbojet in the belly. Armament was to comprise four wing-mounted 20mm cannon.
The first XF15C-1 was flown on 27 February 1945, without the turbojet installed, this fitted by April, but the aircraft was lost on 8 May when it crashed during a landing approach. The second XF15C-1 flew on 9 July 1945, and was joined soon after by the third, both subsequently having their low-set horizontal tail surfaces replaced by a T-tail arrangement. The flight test programme continued until October 1946, by which time the US Navy had lost interest in the mixed power arrangement and cancelled further development.
Engines: 1 x Pratt & Whitney R-2800-34W 18-cylinder two row radial, 2,100hp / 1566 kW
and 1 x Allison-Chalmers J36 (Halford H-1B) turbojet, 1226kgp / 2700-lb
Max take-off weight: 7543 kg / 16630 lb
Empty weight: 5 737 kg
Wingspan: 14.63 m / 47 ft 12 in
Length: 13.41 m / 43 ft 12 in
Height: 4.65 m / 15 ft 3 in
Wing area: 37.16 sq.m / 399.99 sq ft
Max. speed: 469 mph / 755 km/h
Range: 2228 km / 1384 miles