The North American P-51 Mustang is an American single-engine fighter and attack aircraft with long range, featuring a classic tail and fully metallic construction. Its prototype flight took place on October 26, 1940. The P-51 Mustang has gained fame as one of the best fighters of World War II. Replacing the Allison V-1710-39 engine with a Rolls-Royce Merlin engine (P-51 Mustang Mk.Ia version) improved the Mustang's performance. The single-seat fighter impressed with its maximum speed, range, agility, and powerful armament.