06/23/2025. Remarks by Johan Visschedijk: "The USAAC had been impressed by the performance of the XP-39 Airacobra since it first flight on April 6, 1938, and signed on April 13, 1939, a contract with Bell for the construction of thirteen Service trials aircraft designated YP-39 (Model 12) Airacobra (s/n 40-027 to 40-039). These aircraft were to be identical to the XP-39B but with an 1,090 hp V-1710-37 engine. The first YP-39 made its maiden flight on September 13, 1940. This aircraft had its full armament, a 37mm cannon with fifteen rounds, firing through the propeller hub, two 0.50 in (12.7 mm) machine guns with 200 rounds and one 0.30 in (7.62 mm) machine gun with 500 rounds. The vertical tail surfaces were enlarged and some armor had been installed in the cockpit area. All-up weight has been increased to 7,235 lb (3,282 kg).

The thirteen YP-39s (40-027 to 40- 039) were delivered between September 7 and December 16, 1940, and were used for evaluation. Some of them were sent back to Bell to be used in the development of improved versions. Most of them were destroyed in accidents: 40-027 during its 8th flight; 40-029 on January 21, 1942; 40-030 on May 10, 1943; 40-031 on December 22, 1940; 40-036 on March 26, 1942; and 40-039 on June 10, 1942. The remaining examples were withdrawn from use."

The Bell P-39 Airacobra history continues on page 14389.