Boulton Paul Defender Mk.I - No.303 Squadron, RAF Fighter Command, 1940
The Boulton Paul P.83 was designed to Air Ministry Specification F.40/34 for a single-seat monplane fighter of wooden construction that could be built rapidly and in large numbers. As part of the Air Ministry policy of diverting production of the Rolls-Royce Merlin engine to priority projects such as the Hawker Hurricane and Supermarine Spitfire the Air Ministry had specified that all F.40/34 submissions must use the Napier Falcon (a licence-built Hispano-Suiza 12Y-45) with a planned rating of 920 hp. The P.83 was a conventional low-wing monoplane but of wooden construction with plywood skinning over stringers in a semi-monocoque construction.
In the Spring of 1936, Boulton Paul commenced assembly on the first P.83 prototype at their new Wolverhampton facility and made quick progress. With their contemporary turret-fighter being named Defiant, Boulton Paul requested the name Defender for their new fighter and this was agreed with the Air Ministry. Making it's maiden flight on April 4th, 1937 (piloted by Boulton Paul's chief test pilot Cecil Feather) the Defender demonstrated good handling and an impressive rate of climb. Service pilots reported that the Defender could climb faster than both the Spitfire and Hurricane but that its top speed was somewhere inbetween the two. In June 1937 the Air Ministry placed an order for 240 aircraft and whilst official acceptance trials did not commence until July 1938 the first Defender Squadrons were formed in early 1939.
(Arsenal de l'aeronautique VG-33)