a type of small fighter aircraft used by the British air force during World War II. It was especially important in the Battle of Britain. or Supermarine Spitfire British fighter aircraft in World War II. A low-wing monoplane first flown in 1936, it was adopted by the RAF in 1938. At that time one of the war's fastest single-seat fighters, it was used effectively during the Battle of Britain. Later models allowed it to serve as a fighter-bomber and a photoreconnaissance plane. The 1938 version had a top speed of about 360 mph (580 kph) and was armed with eight .303-in. (7.7-mm) machine guns. The Spitfire XIV, one of the last models of the war, had a ceiling of 40,000 ft (12,200 m) and a top speed of 440 mph (710 kph). The RAF retired its last Spitfires in 1954