The Short S.29 Stirling was a four engine heavy bomber used by Great Britain during World War II.
Standard armament carried onboard was around ten defensive machine guns placed around the aircraft and a maximum of 6,300 kilograms worth of bombs. The Stirling was admittedly outdated by 1944-1945 but it continued to operate fairly effectively in combat demonstrating the reliability of the design.
The first variant of the Short Stirling series was the Mk II which was basically Mk I with 1,600 hp R-2600-A5B Cyclone radials. (These proved inferior to the Mk I and were abandoned.) [N 1] A contract for the construction of 140 examples of this variant in Canada was canceled after the conversion of two Mk Is and construction of three production examples. The Mk III then followed suit, though it too was basically Mk I with 1,650 hp Bristol Hercules XVI 14 cylinder sleeve valve radials The Mk IV was an Mk III configured as glider tug and special transport aircraft and the Mk V was an Mk III configured as strategic transport.
The Stirling was created in response to Air Ministry Specification B.12/36 of July 1936, which called for a heavy bomber with a wingspan of less than 100 ft,[N 2] while possessing a range and bomb load greatly exceeding any previously envisaged. The wingspan limit forced the designers to employ a low aspect ratio wing, which endowing the Stirling with outstanding maneuverability for such a large aircraft, but generated high induced drag, restricting the maximum operation ceiling.[N 3]
The relatively advanced nature of the design prompted Short and Harland Ltd to gain information on the aircraft's flying qualities and handling characteristics by building a two-seat half scale model designated the S.31, which first flew in 1938 with four 90 hp Niagara III seven cylinder radials. Later fitted with 115 hp (86 kW) Niagaras, the S.31 made over 100 flights before it was scrapped in 1943.
The first prototype, powered by four 1,375 hp (1,025 kW)Hercules II engines, made its first flight on 14 May 1939, only to be written off when the undercarriage collapsed during the landing, due to brake failure. The second prototype, with the same make of engine, flew seven months later, followed by the first production example with Hercules XIs producing 1,595 hp (1,189 kW) each, which flew on 7 May 1940.
The first unit to receive Stirlings was 7 Squadron at Leeming, who began to take delivery in August 1940. The first mission involving Stirlings involved three aircraft from 7 Squadron attacking oil storage tanks at Rotterdam on the night of 10/11 February 1941.
Eventually equipping thirteen squadrons in the bombing role, examples began to be withdrawn for other tasks following the buildup of Lancaster and Halifax deliveries. The last operational bomber sortie flown with Stirlings was carried out by 149 Squadron on 8 September 1944.
As more Lancasters and Halifaxes were assigned to bomber units, a pair of Mk III Stirlings were converted to Mk IV standard, to serve as prototypes transport aircraft and glider tugs. These retained the Mk IIIs engines, but had the nose and tail turrets removed and the apertures faired over, and glider towing equipment fitted in the rear fuselage. Both prototypes were first flown in 1943 - one as a transport and one as a tug.[N 4]
Initially entering service with 299 Squadron on 23 January 1944, the Mk IVs immediately commenced operations, conducting low level night drops of supplies for the French Resistance. Stirling transports were also assigned to 190 and 620 Squadrons at Fairford, and 196 Squadron at Keevil. All four squadron were employed in glider towing during Operation Overlord.
- Shorts had planned a different Mk II. Known as the S.34 'Stirling II', and intended to fulfill Specification B.1/39, the 'Ideal Bomber' featured increased wingspan, slimmed rear fuselage with twin tail fins, a pair of twin 20 mm cannon turrets and a capacious bomb bay. Designed to be powered by high altitude Hercules engines, the S.34 did not progress beyond the mock-up stage, as Bomber Command had already chosen it's new aircraft types
- Many sources incorrectly state that this limit was imposed on the grounds that 100ft was the maximum width of the open doors in standard RAF hangers of the time. In fact there were no hangers with doors of this width. The most common bomber station hanger was the 152 ft wide C Type, which had a maximum door width of 126 ft. The limit was actually imposed to keep the Stirling's size and weight down, in order to curtail take off/landing runs and the need for hard runways, while allowing easy storage in Type C hangers.
- Shorts had originally designed the Stirling with a 112 ft wingspan. Following a request to reduce this, Short submitted a design with a 102 ft span, which they considered the shortest desirable. When told that 100 ft was the absolute maximum, the company reluctantly shortened the wingspan further, to 99 ft 1 in.
- Most production examples of the Mk IV retained the tail turret.
- Aeroplane Magazine August 2002 Page 40
- World Aircraft Information Files Aviation Partwork. Midsummer Books Ltd. File 253 Sheet 1 (World Military Aircraft: Short Stirling - First of the heavies)
- Gunston, Bill. Illustrated Directory of Fighting Aircraft of World War II. Salamander Books. 1988. ISBN 0-86101-390-5 Page 462
- Mason, Francis K. The British Bomber since 1914. Putnam. 1994. ISBN 0 85177 861 5 Page 313
- Aeroplane Magazine Database section August 2002 Pages 39-40
- Green, William. Famous Bombers of the Second World War. Purnell Book Services. 1975. Page 110
- Green, William - Bombers. 1975. Page 109
- Green, William - Bombers. 1975. Page 111
- World Aircraft Information Files. File 253 Sheet 2 (World Military Aircraft: Short Stirling - Transports and tugs)