The Boulton-Paul Defiant Designer : J.D North Boulton Paul ( Wolverhampton ) Description : Two Seat Fighter Type : Low Wing Monoplane Wingspan : 39ft 4 inches ( 11.99 m ) Length : 35 ft 4 inches ( 10.77 m ) Height : 11ft 4inches ( 3.45 m ) Wing Area : 250 sq feet ( 23.22 m sq ) Power Plant Mk 1 : Rolls Royce Merlin III
V12 liquid cooled piston engine Power Plant Mk 2 : Rolls Royce Merlin XX V12
liquid cooled piston engine B.H.P. Mk 1 : 1030 bhp at 16,250 ft ( 4955
m ) B.H.P. Mk 2: 1260 bhp at 12,250 ft ( 3735
m ) Armament : 4 Browning 0.303 machine guns Mounted
in a power operated turret. Weight empty : 6078 lb ( 2758 kg ) Weight Loaded (normal) : 8424 lb ( 3822 kg
) Performance Max Speed Mk 1 : 304 mph ( 490 kph ) at 17,000
ft ( 5180 m ) Max Speed Mk 2 : 313 mph ( 505 kph ) at 19,000
ft ( 5790 m ) Service Ceiling : 36,000 ft ( 10,950 m ) Range : 425 miles ( 684 km ) First Flight : 11 August 1937 ( prototype
) Mk 1 on the 30th July 1939 Mk 2 on the 20 July 1940 Service Entry Mk 1 : May 1940 Squadrons allocated the Defiant
during the Battle.
