<p>In 1940, and with Europe already at war, the US Army Air Corps knew that it was essential to begin preparations for the very real possibility that in the not too distant future, and despite a national isolationist policy which was still very active, the United States of America would become involved in that war. The only positive action which could be taken at that time was to intensify the training program so that a maximum number of active and reserve flying crews would be available if the need arose.
</p>
<p>As a part of this general thinking, the US Army had already begun evaluation of the Cessna T-50 as an 'off-the-shelf' twin-engined trainer which would prove suitable for the transition of a pilot qualified on single-engined aircraft to a twin-engined aircraft and its very different handling technique. Procured as the AT-8, Cessna's T-50 was to be built in large numbers.
</p>
<p>For the more specific transition to a 'high-performance' twin-engined bomber it was considered that something less stable than the T-50 was needed. However, Curtiss-Wright had anticipated this requirement in the design of their Model 25, a twin-engined pilot transition trainer which had the take-off and landing characteristics of a light bomber aircraft. The Model 25 was of low-wing cantilever monoplane configuration, provided with retractable tailwheel-type landing gear, and powered by two Lycoming R-680-9 radial engines, with Hamilton-Standard two-bladed constant-speed metal propellers. The single prototype acquired for evaluation had a welded steel-tube fuselage structure, and the wings, fuselage and tail units were fabric-covered.
</p>
<p>Evaluation proving satisfactory, the type was ordered into production under the designation AT-9. These production examples differed from the prototype by being of all-metal construction. A total of 491 AT-9s was produced, and these aircraft were followed into service by 300 AT-9As which had R-680-11 engines and revised hydraulics. These remained in use for a comparatively short time, for the USA's involvement in World War II in late 1941 resulted in the early development of far more effective training aircraft.
<item><hi format=bold>Powerplant:</hi> two 295-hp (220-kW) Lycoming R-680-9 radial piston engines
<item><hi format=bold>Performance:</hi> maximum speed 197 mph (317 km/h; cruising speed 175 mph (282 km/h); range 750 miles (1,207 km)
<item><hi format=bold>Weights:</hi> empty 4,600 lb (2,087 kg); maximum take off 6,000 lb (2,722 kg)
<item><hi format=bold>Dimensions:</hi> span 40 ft 4 in (12.29 m); length 31 ft 8 in (9.65 m); height 9 ft 10 in (2.99 m); wing area 233 sq ft (21.65 m<su>2</su>)
