Boulton-Paul Defiant

The Boulton Paul Defiant is a British interceptor aircraft that served with the Royal Air Force (RAF) during World War II. The Defiant was designed and built by Boulton Paul Aircraft as a "turret fighter", without any fixed forward-firing guns, also found in the Blackburn Roc of the Royal Navy.

Luftwaffe fighters suffered losses when "bouncing" flights of Defiants from the rear, apparently mistaking them for Hurricanes.[26] The German pilots were unaware of the Defiant's rear-firing armament and encountered concentrated defensive fire. The Luftwaffe changed tactics, to outmaneuver the Defiant and attack from below or dead ahead, where the turret guns offered no defence. Defiant losses quickly mounted, particularly among the gunners, who were often unable to leave stricken aircraft. The additional weight of the turret and the second crewman plus the aerodynamic drag gave the Defiant a lower performance than conventional single-seat fighter aircraft.

In combat, the Defiant was found to be reasonably effective at destroying bombers but was vulnerable to the Luftwaffe's more manoeuvrable, single-seat Messerschmitt Bf 109 fighters. The lack of forward-firing armament proved to be a great weakness in daylight combat and its potential was realised only when it was converted to a night fighter.[2] It eventually equipped thirteen squadrons in this role,[3] compared to just two squadrons as a day-fighter.[4] In mid-1942 it was replaced by better performing night-fighters, the Bristol Beaufighter and de Havilland Mosquito.[3]

The Defiant continued to find use in gunnery training, target towing, electronic countermeasures and air-sea rescue. Among RAF pilots it had the nickname "Daffy".