About the Mustang... In late 1939, with the likelihood of full scale war in Europe a major concern, the British Royal Air Force was looking seriously at methods of quickly increasing its fighter strength. In April 1940, the British Air Purchasing Commission approached North American Aviation with the intent of having them build P-40's for the RAF. Since the P-40 design went back to 1933, James H. "Dutch" Kendelberger, the president of North American offered to build an entirely new advanced fighter using the same Allison V-1710-39 engine, used on the P-40. It was said that "Dutch" got his inspiration for the P-51 after a 1938 tour of aircraft industries in Great Britain and Germany.1 North American's only previous fighter experience was with the NA-50A, but Dutch collaborated with J.L. "Lee" Atwood2 to formulate an outline for the project. The British agreed on the new type, NA-73X, only on the stipulation that a prototype be on hand within 120 days. North American designers Raymond Rice and Edgar Schmued, the latter had worked for Fokker and Messerschmitt in 1925,3 immediately set about meeting the requirements. A prototype was finished in 117 days minus the engine. Wheels also had to be borrowed from an AT-6 trainer. Six weeks later, and after several modifications, the aircraft took to the air October 26,1940.