Armstrong Whitworth Whitley

With the issuing in July 1934 of Specification B.3/34 the Air Ministry were looking for a twin-engined bomber. Armstrong Whitworth's submission to this specification would be led by the company's chief designer John Lloyd. With design work in progress an order for 80 Whitleys was placed seven months before the prototype flew.

The prototype would be ready for its maiden flight on the 17th March 1936 at Whitley Abbey with Alan Campbell-Orde at the controls, with power supplied by a pair of Armstrong Siddeley Tiger X engines. Trials of the Royal Air Force's new bomber were done in Autumn 1936 at Martlehsam Heath by the Aeroplane and Armament Experimental Establishment. A second prototype would have a specially written specification for it, B.21/35, and this made its maiden flight on the 24th February 1937, powered by the Tiger XI engine, and was flown by Charles Turner Hughes.

The Whitley would enter service during March 1937 with No. 10 Squadron based at RAF Dishforth receiving their first Mk Is on the 9th, to replace their Handley Page Heyford aircraft. Able to house a crew of up to 5, armament would consist of a single 0.303-in Vickers machine-gun in nose and tail turrets. Of the original order of 80, 34 would be Mk Is whilst the rest would be Mk IIs which were powered by Tiger VIII engines. A further order for 80 Whitleys was placed and these would be the Mk III. The armament on this new variant was upgraded, firstly the bomb-bay was changed to allow larger bombs to be carried, the nose turret was changed to a Nash and Thompson turret and two more machine-guns in the form of 0.303-in Brownings were added to a new retractable turret underneath the fuselage.

Flying from Hucknall on the 11th February 1938 a Whitly Mk I was tested with Rolls-Royce Merlin IIs, however the programme was suspended after the second flight which had to be curtailed due to engine failure. After the test programme was resumed the aircraft was sent to the A&AEE at Martlesham Heath for further tests during April and May.

The next production version, which first flew on the 5th April 1939, was the Mk IV which featured a number of changes. The first change saw the aircraft now powered by the 1,030-hp Rolls-Royce Merlin IV engine. The second change saw a pair of wing tanks added whilst other changes included improvements to the bomb-aimers view with the addition in the lower nose of a clear panel. The armament for the rear gunner was also upgraded to four 0.303-in Browing guns. Powered by the 1,145-hp Merlin X seven Whitley Mk IVAs were produced alongside 26 Mk IVs.

Further changes to the design saw the Whitley Mk V appear which was to be the most produced version and would also be powered by Merlin engines. Once again fuel capacity was improved and extra fuel could be carried in the bomb-bay if needed. On the leading edges of the wings rubber de-icer boots were added. The rear of the aircraft was also redesigned to increase the rear gunner's field of fire, this would see the rear fuselage lengthened 1ft 3in. The fins was also given straight leading edges.

With the Rolls-Royce Merlin in demand for use in a number of aircraft a Pratt & Whitney powered Whitley Mk VI was considered in case Merlin engines became unavailable. In the end this proposed aircraft would never go into production. Based on the Mk V the Whitley Mk VII was designed for operational service with Coastal Command. This would see the installation of Air-to-Surface Vessel Mk II radar and the fitting in the rear of the fuselage and bomb-bay of additional fuel tanks.

Armstrong Whitworth Whitleys were in action with Bomber Command on the same day as Britain and France declared war on Germany, 3rd September 1939, when 10 aircraft flew over Bremen, Hamburg and the Ruhr in Germany dropping leaflets. It would be the Whitley that became the first Royal Air Force bomber to operate over Berlin, Germany when three Whitley Mk IVs from No. 10 Squadron dropped propaganda leaflets over the city on the 1st October 1939, losing one aircraft. Whitleys would also take part in the first bombing raid on Berlin, Germany on the 25th August 1940 alongside the Handley Page Hampden and Vickers Wellington. The type would also be called on the day after Italy declared war on Britain and France when on the 11th June 1940 raids were carried out on Genoa and Turin. However, of the 36 aircraft that took part only 13 reached their target as engine problems and weather hampered the operation.

With the Short Stirling and Handley Page Halifax four-engined bombers now in service and with the Avro Lancaster entering service the Whitley's time in Bomber Command was coming to an end. Its last official sortie took place on the 29th April 1942 with a raid on Ostend, Belgium. However Whitleys from Operational Training Units would take part in the raid on Cologne, Germany on the 30th May 1942 in the first ever '1,000 Bomber' attack codenamed Operation Millennium.

The Whitley would also serve with Coastal Command and its service began when No. 58 Squadron were seconded in September 1939. This would see them patrol over the English Channel until February 1940 when they operated as part of Bomber Command again. Other Whitley squadrons would also patrol over the Bay of Biscay. It would take over 2 years before the type scored its first U-boat victory when on the 30th November 1941 No. 502 Squadron sank U-205 in the Bay of Biscay.

The type would also be used for a number of special operations. These included Operation Columba which saw homing pigeons dropped over occupied Europe in the hope that people who came across the pigeons could provide intelligence on German military activities in the area. It would be on the 8th April 1941 that a Whitley would perform the first drop of pigeons for the operation. The aircraft was also involved in Operation Biting on the 27th February 1942 which saw them drop paratroopers at Bruneval, France for what was a successful mission to capture parts of German radar. Two squadrons, Nos. 138 and 161, would also serve at RAF Tempsford undertaking special duties. This involved supplying arms and equipment to the Resistance and transport agents by parachute drop into occupied countries.

Other duties for the Whitley saw it used as a glider tug and for parachute training. During May 1942 the British Overseas Airways Corporation received 15 Mk Vs which had their armament removed and fuel tanks added to the bomb-bays. These would be used by BOAC on their Gibraltar to Malta route.

By the time the last Armstrong Whitworth Whitley rolled of the production line a total of 1,815 had been built.