The P-51 Mustang is arguably the world's most famous fighter of all time. With its long range, superior speed, lethal weaponry and outstanding maneuverability, the Mustang has proven to be unequaled as an escort fighter. It was also an outstanding interceptor and ground attacker as well as reconnaissance aircraft. The fact that the Mustang remained in service with various Air Forces around the world well into the 1980s is a testament to its superb abilities.
The P-51 began its career as a result of the British considering North American Aviation as a potential supplier of the Curtiss P-40. Rather than build someone else's airplane, North American designers Raymond Rice and Edgar Schmued instead offered to create a better aircraft. The British agreed to let the company try, provided that it could produce a prototype within 120 days. North American Aviation made the deadline, calling their new prototype the NA-73, which made its maiden flight on October 26, 1940.
The Mustang was a very advanced design and became one of the greatest achievements in aviation history. It employed a laminar flow wing and other innovative features such as a centrally located radiator scoop and airflow ducting, which combined made it highly effective in many regimes. The British did not need to wait until the October deadline to realize the potential of this new fighter. In March 1940 they ordered 320 of the unproven and unfinished plane designs. Under this contract, two of the new fighters were to be given to the USAAF for testing. The designation of these American aircraft was XP-51.
Surprising, while the British anxiously awaited delivery of their new fighter, the USAAF all but ignored the Mustang while focusing their attention on the P-38 Lightning and the P-47 Thunderbolt. Meanwhile the British, while happy with the low altitude performance of the aircraft, were less than thrilled with the performance of the Allison powered Mustang’s climbing rate past 17,000 ft. In an attempt to rectify this high-altitude performance issue, they tried merging the Mustang body with a different engine - the Rolls-Royce Merlin.The result astonished everyone and there was no doubt that a truly advanced fighter had been born. This Rolls Royce powered Mustang became the P-51 Mustang as we know it today.