Armstrong Whitworth Whitley - Variants

Variants

Following the two prototypes (K4586 and K4587), at the outbreak of the war the RAF had 207 Whitleys in service ranging from Mk I to Mk IV types, with improved versions following:

Mk I

Powered by 795 hp (593 kW) Armstrong Siddeley Tiger IX air-cooled radial engines: 34 built

Mk II

Powered by 920 hp (690 kW) two-stage supercharged Tiger VIII engines: 46 built

Mk III

Powered by Tiger VIII engines, retractable "dustbin" ventral turret fitted aft of the wing root armed with two .303 in (7.7 mm) machine guns, hydraulically operated bomb bay doors and ability to carry larger bombs: 80 built

Mk IV

Powered by 1,030 hp (770 kW) Rolls-Royce Merlin IV inline liquid-cooled engines, increased fuel capacity, extended bomb-aimer's transparency, produced from 1938: 33 built

Mk IVA

Powered by 1,145 hp (854 kW) Merlin X engines: seven built

Mk V

The main wartime production version based on the Mk IV, modified fins, leading edge de-icing, manually operated tail and retractable ventral turrets replaced with a Nash & Thompson powered turret equipped with four .303 in (7.7 mm) Browning machine guns, tail fuselage extended by 15 in (381 mm) to improve the field of fire. First flew in December 1938, production ceased in June 1943: 1,466 built

Mk VI

Proposed Pratt & Whitney- or Merlin XX-powered version: none built

Mk VII

Designed for service with Coastal Command and carried a sixth crew member, capable of longer-range flights (2,300 mi/3,700 km compared to the early version's 1,250 mi/2,011 km) having additional fuel tanks fitted in the bomb bay and fuselage, equipped with Air to Surface Vessel (ASV) radar for anti-shipping patrols with an additional four 'stickleback' dorsal radar masts and other antennae: 146 built