The Armstrong Whitworth A.W.38 Whitley was a British medium bomber aircraft of the 1930s. It was one of three twin-engined, front line medium bomber types that were in service with the Royal Air Force (RAF) at the outbreak of the Second World War. Alongside the Vickers Wellington and the Handley Page Hampden, the Whitley was developed during the mid-1930s according to Air Ministry Specification B.3/34, which it was subsequently selected to meet. In 1937, the Whitley formally entered into RAF squadron service; it was the first of the three medium bombers to be introduced. Following the outbreak of war in September 1939, the Whitley participated in the first RAF bombing raid upon German territory and remained an integral part of the early British bomber offensive. In 1942 it was superseded as a bomber by the larger four-engined "heavies" such as the Avro Lancaster. Its front-line service included maritime reconnaissance with Coastal Command and the second line roles of glider-tug, trainer and transport aircraft. The type was also procured by British Overseas Airways Corporation as a civilian freighter aircraft. The aircraft was named after Whitley, a suburb of Coventry, home of Whitley plant, belonging to Armstrong Whitworth. The Armstrong Whitworth Whitley was a twin-engined heavy bomber, initially being powered by a pair of 795 hp (593 kW). Armstrong Siddeley Tiger IX radial engines. More advanced models of the Tiger engine equipped some of the later variants of the Whitley; starting with the Whitley Mk IV variant, the Tigers were replaced by a pair of 1,030 hp (770 kW) Rolls-Royce Merlin IV V12 engines. According to Moyes, the adoption of the Merlin engine gave the Whitley a considerable boost in performance. The Whitley had a crew of five: a pilot, co-pilot/navigator, a bomb aimer, a wireless operator and a rear gunner. The pilot and second pilot/navigator sat side by side in the cockpit, with the wireless operator further back. The navigator, his seat mounted on rails and able to pivot, slid backwards and rotated to the left to use the chart table behind him after take-off. The bomb aimer position was in the nose with a gun turret located directly above. The fuselage aft of the wireless operator was divided horizontally by the bomb bay; behind the bomb bay was the main entrance and aft of that the rear turret. The bombs were stowed in two bomb bays housed within the fuselage, along with a further 14 smaller cells in the wing. Other sources state there were 16 "cells", two groups of two in the fuselage and four groups of three in the wings, plus two smaller cells for parachute flares in the rear fuselage. Bomb racks capable of holding larger bombs were installed on the Whitley Mk III variant. The early examples had a nose turret and rear turret, both being manually operated with one Vickers 0.303 machine gun apiece. On the Whitley Mk III this arrangement was substantially revised: a new retractable ventral 'dustbin' position was installed mounting twin .303 in (7.7 mm) Browning machine-guns and the nose turret was also upgraded to a Nash & Thompson power-operated turret. On the Whitley Mk IV, the tail and ventral turrets were replaced with a Nash & Thompson power-operated tail turret mounting four Browning .303 machine guns; upon the adoption of this turret arrangement, the Whitley became the most powerfully armed bomber in the world against attacks from the rear. The fuselage comprised three sections, with the main frames being riveted with the skin and the intermediate sections being riveted to the inside flanges of the longitudinal stringers. Extensive use of Alclad sheeting was made. Fuel was carried in three tanks, a pair of 182 imp gal (830 L) tanks in the leading edge of each outer wing and one 155 imp gal (700 L) tank in the roof of the fuselage, over the spar center section; two auxiliary fuel tanks could be installed in the front fuselage bomb bay compartment. The inner leading edges contained the oil tanks, which doubled as radiant oil coolers. To ease production, a deliberate effort was made to reduce component count and standardise parts. The fuselage proved to be robust enough to withstand severe damage. The Whitley featured a large rectangular-shaped wing; its appearance led to the aircraft receiving the nickname "the flying barn door". Like the fuselage, the wings were formed from three sections, being built up around a large box spar with the leading and trailing edges being fixed onto the spar at each rib point. The forward surfaces of the wings were composed of flush-riveted, smooth and unstressed metal sheeting; the rear 2/3rds aft of the box spar to the trailing edge, as well as the ailerons and split flaps was fabric covered. The inner structure of the split flaps was composed of duralumin and ran between the ailerons and the fuselage, being set at a 15–20 degree position for taking off and at a 60 degree position during landing. The tailplanes employed a similar construction to that of the wings, the fins being braced to the fuselage using metal struts; the elevators and rudders incorporated servo-balancing trim tabs. For details of development, operational history, civilian service and 8 variants, click here.
