Curtiss 59B / YA-10
Curtiss won a contract for five service test YA-8 (Model 59A) aircraft on 29 September 1931, and one YA-8 was reworked as the experimental YA-10 (Model 59B) with a 466kW radial engine.
The liquid-cooled Curtiss "Conqueror" engine was removed and replaced with a Pratt & Whitney air-cooled radial engine. The conversion was completed by September 1932 and the aircraft was re-designated YA-10 because of the engine change.
The performance of the YA-10 was about the same as the A-8, but the air cooled radial engine was favoured over a liquid cooled engine. After testing was complete, the Army changed the order for 46 A-8Bs (with geared "Conqueror" engines) to A-12s. The Curtiss A-12 was equipped with a Pratt & Whitney radial engine and was essentially a production version of the YA-10.
The YA-10 remained in service through the late 1930s. After service testing, the aircraft was assigned to the 3rd Attack Group for operational service. In the summer of 1934, the YA-10 was assigned to the Command and General Staff School. It was scrapped in early 1939.
Engine: 1 x 470kW Pratt & Whitney R-1690-9 (R-1690D) Hornet radial
Take-off weight: 2783 kg / 6135 lb
Wingspan: 13.5 m / 44 ft 3 in
Length: 9.9 m / 32 ft 6 in
Height: 2.75 m / 9 ft 0 in
Max. speed: 280 km/h / 174 mph
Cruise speed: 238 km/h / 148 mph
Ceiling: 4570 m / 15000 ft
Range: 800 km / 497 miles