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The Boulton Paul P.82 Defiant, designed and built in Pendeford, Wolverhampton, was the first RAF fighter in service with a four-gun turret. The prototype, K8310, made its initial flight on 11 August, 1937 and the two-seat all-metal monoplane, with forward-facing pilot and rear-facing gunner in a hydraulically operated turret, was soon snapped up by the Air Ministry. With a fully retractable undercarriage and powered by the Rolls Royce 'Merlin' engine, it was fairly speedy at 313mph and had a reasonable performance when compared with other British single-seat fighters like the Hurricane and Spitfire.
The Defiant Mark I was designed as an attempt to overcome the need to not only point the nose of a fighter at its target in order to bring the guns to bear, but also to relieve the pilot of trying to simultaneously fly the aircraft and concentrate on his target. Instead, the rear-facing gunner would do the attacking, relying on the pilot to put him in a position that could do the most damage to an enemy aircraft. In theory, the Defiant would intercept enemy bombers from below, the gunner firing from all four .303 Browning machine guns into the belly of the target. However, communication between the pilot and gunner was somewhat limited. Despite this, the Defiant went into active service soon after the 'Phoney War' went 'real' and the British Expeditionary Forces were sent to France to combat the advancing German occupation.
Defying the Odds
The first Defiant squadron, 264, began to re-arm with the new aircraft at RAF Martlesham Heath on 8 December, 1939. It was with this squadron that the Defiant first saw combat. On 12 May, 1940 during the evacuation of Dunkirk by the British forces, the Defiant held its own in the skies above the fleeing ships. By the end of May, 65 enemy aircraft had fallen to the guns of the Defiant, but this was most probably achieved because enemy pilots mistook the Defiant for its slightly smaller cousin, the Hurricane, and when making rear attacks were thus presented with the fury of the turret defences.
But the initial successes were not to last and the Defiants soon became cannon-fodder as Luftwaffe pilots changed tactics, using head-on and belly attacks. On 19 July, 1940, six out of nine Defiants of 141 Squadron were shot down and the remaining three only survived due to the intervention of the Hurricanes of 111 Squadron. Losses increased dramatically and by August 1940, the aircraft were withdrawn from daylight operations by Fighter Command.
Under the Cover of Darkness
It was instead decided to use the Defiant in a night-fighter role. The comparatively new and highly secret Airborne Interception (AI) radar was installed in many of the Mk I aircraft. The jet-black-painted Defiant looked like a shark's shadow and proved to be just as fierce in the night sky. A valuable addition to Britain's night defences during the Blitz years of 1940 - 1941, Defiant night-fighter squadrons racked up more kills per interception than any of their contemporaries. However, as more radar-equipped aircraft like the Beaufighter and Mosquito entered service, the Defiant found itself out-gunned and out-performed.
The Defiant saw night-fighter service with 13 RAF squadrons over the course of 1941 to 1943, but as the war progressed, the aircraft were phased out of frontline service and were being used for target-tugs with air gunnery schools and anti-aircraft co-operation units. Others were modified for use by the Air/Sea Rescue Service.
The sole surviving Boulton Paul Defiant night-fighter (N1671), while not airworthy, can be found at the RAF Museum, Hendon. If you aren't able to see this fine example, there are many models of the Defiant available in kit form, including the night-fighter type.