The long period which passed between the first conception of the Defiant turret fighter and its operational acceptance impaired its usefulness. The delays in production, which resulted in only three aircraft being delivered before the outbreak of war, meant that it could not be used in 1940 in its originally planned role-that of standing defensive patrols and was forced into action as an interceptor alongside the Spitfire and Hurricane.
The first unit to equip with the type was No 264 Squadron, which moved to Martlesham Heath to take delivery in December 1939. Engine and hydraulic malfunctions caused a grounding order late in January 1940, which was lifted the following month. The Defiant first entered combat in May, and achieved a somewhat patchy record. Against bombers, the Defiant's extremely heavy turret armament was very effective; and by operating mixed formations of Defiants and Hurricanes the RAF could make use of the superficial resemblance between the two types to confuse and trap German fighters. However, when the Messerschmitts caught Defiants on their own, and recognised them for what they were, they inflicted appalling casualties. The technique of the pilot positioning his aircraft with the gunner's field of fire in mind was feasible against slow bombers but quite impossible in a fast dogfight. Aircrew losses were high in Nos. 264 and 141 Squadrons; in an emergency a Defiant gunner had very little chance of escaping from his turret
Most prominent feature from the side is the gun turret, mounted immediately behind the pilot's cockpit. Large, triangular tail. From below, thick, straight wings, with the outer section swept forward, house the wide main undercarriage.
|Power and specifications|
|Powerplant||One 1,030 hp Rolls-Royce Merlin III twelve-cylinder liquid-cooled engine|
|Span||39ft 4in (11.99m)|
|Length||35ft 4in (10.77m)|
|Max Speed||304 mph (490km/h) at 17,000 ft (5,181m)|
|Armament||Four .303in Browning machine guns mounted in electrically-operated turret.|
|Accomodation||Pilot and air gunner.|