The Curtiss AT-9 was designed to be difficult to fly and land, or perhaps more precisely, it was designed to mimic the handling characteristics of much larger, heavier, and speedier airplanes. The 'AT' in AT-9 stood for 'advanced trainer', and the aircraft was intended to teach cadets fresh off of primary trainers how to fly high performance twin-engine aircraft, which by 1940 were set to become a large portion of Army Air Force combat equipment.
The AT-9 was a product of Curtiss-Wright's Airplane Division at St. Louis. Originally the Curtiss-Robertson company, after Curtiss and Wright merged in 1929 it became the new firm's civil aviation shop. In 1934, while the original Curtiss facility at Buffalo was designing the Hawk 75 pursuit ship, the St. Louis designers were building the CW-19 Coupe. Though this was a two seat aircraft meant for civil customers, with an engine of just 90 hp, the CW-19 was a low-wing cantilever monoplane of all metal stressed-skin construction, and was quite capable of further development with more powerful motors. The lines of its fuselage, and its wing-plan, can clearly be seen in subsequent single-engine designs out of St. Louis, such as the CW-21 interceptor, with its 900hp Cyclone engine, and the CW-22 Falcon trainer.
When the design team at St. Louis, led by George Page, set out in 1940 to create a twin-engine transition trainer for the Army (under the company designation CW-25), what they produced was in essence a CW-19 scaled up and altered to accommodate two engines instead of one. The prototype, which first flew early in 1941, had a squared-off fuselage of steel tube and fabric, owing to concerns over whether the supply of aluminum would be sufficient for both combat and training planes, but when the Army accepted the design, this was discarded in favor of the modern all metal construction employed by the Airplane Division ever since the ancestral CW-19. The Army initially ordered 150 AT-9 aircraft, which were among the first items produced at a mammoth new facility being built for the St. Louis branch of Curtiss-Wright with government assistance. These aircraft reached training units early in 1942, and were followed by another 341, plus an additional 300 examples of a slightly modified version, designated AT-9A, ordered in 1942.
The AT-9 had a wing loading similar to that of the CW-21 interceptor, but its engines provided only two thirds the horsepower. This relative lack of engine power was at the root of most of the AT-9's 'tricky' flight characteristics. Poor stability in pitch and yaw owed something to this, as the aircraft just was not moving fast enough to give the stabilizing surfaces all the bite they needed, and so did the AT-9's proneness to sudden stalls, for even at its fastest, an AT-9 was not going much faster than its stall speed. A steep descent was required to keep up speed when landing, and pulling up the nose to do a 'three point' landing could easily result in a stall and a wreck. On the other hand, the AT-9 was fully aerobatic, and there were some pilots, cadets as well as instructors, who liked the type immensely, describing it as a 'hot-rod', and a real treat to fly. The AT-9 was certainly a fast and responsive machine by compare to basic trainers, and to other twin engined advanced trainers serving alongside it, such as Beechcraft's AT-10 and Cessna's AT-17. There is room to wonder how the AT-9 might have performed and handled had it been fitted with a pair of 450hp Wasp Juniors, rather than a pair of 295hp Lycomings.
This model represents AT-9 41-5891 early in its service at Williams Field in Arizona. This aircraft was one of the very last of the first production batch of 150, and still bears the factory applied national markings, in a style which lingered in training units for some months after removal of red centers and stripes was ordered. The letter 'Y' on the fuselage indicated Williams Field in the sometimes opaque coding system employed by Army training commands, introduced around May of 1942. An in-flight photograph shows this machine with the fuselage codes, but with its cowlings in bare metal, and with no anti-glare panel.
