North American P-51 Mustang variants
Over twenty variants of the North American P-51 Mustang fighter were produced from 1940, when it first flew, to after World War II, some of which were employed also in the Korean War and in several other conflicts. Allison-engined Mustangs NA-73X The prototype of the Mustang, designated NA-73X, was rolled out by North American Aviation on 9 September 1940, albeit without an engine, and was first flown the following 26 October. The Mustang was originally designed to use a low-altitude rated Allison V-1710 engine. Unlike later models, Allison-powered Mustangs were characterized by the carburetor air intake placed on the dorsal surface of the nose, immediately behind the propeller. Mustang Mk I (NA-73 and NA-83) The first production contract was awarded by the British for 320 NA-73 fighters, named Mustang Mk I by the British Purchasing Commission; a second British contract soon followed, which called for 300 more (NA-83) Mustang Mk I fighters. Contractual arrangements were also made for two aircraft from the first order to be delivered to the USAAC for evaluation; these two airframes, 41-038 and 41-039 respectively, were designated XP-51. The first RAF Mustang Mk Is were delivered to 26 Squadron at RAF Gatwick in February 1942 and