Having made it back safely from the arduous trip to Pilsen in Czechoslovakia, Alan embarked on his 13th mission in the same aircraft on 27th April 1942. Q9313 HA-Q, commanded by S/Ldr Ashworth, departed Marham at 2145 alongside 4 other Stirlings, with Cologne as the target. However, this flight proved to be somewhat shorter than his earlier ones, since the aircraft had to return to base with technical problems, as noted in Alan’s logbook entry below.
This is confirmed in the extract from the Squadron Operations Record Book (ORB) which states that “owing to 3 airscrew exactors becoming U/S, bombs were jettisoned, 51.10N, 02.20E, 23.02 hrs at 8000 ft, aircraft then turned for base”, landing at 2345, 2 hours after departure. The Stirling was a very sophisticated aircraft for its time which relied heavily on electrical power for the various systems on board, including its landing gear and flaps. The “exactor” engine controls, which did not use the traditional push and pull rod system, were supposed to provide precise and responsive throttle movement. However, the exactors were very problematic and prone to failure, with crews often reporting no engine response when advancing the throttles for take-off or the engines continuing at high power when closing the throttles for landing, while during flight the throttles also tended to slip back. Although the failure of 3 exactors on Q9313 would certainly have made life very difficult for the crew, it is clear from Alan’s logbook that the ground engineers were able to fix the problems, as it was airborne again on 29th April 1942 for a 4 hour cross country formation navigation exercise at 150 feet!
Extracts From AIR 27/1350 (April 1942) 218 Squadron ORB – Source: National Archives:
Compared to its twin-engine predecessors, like the Wellington and Hampden, the Stirling was a very large and complex aircraft, with a combination of mechanical, electrical and hydraulic systems, the management of which led the RAF to create the role of “flight engineer”. The aircraft was designed and built by Short Brothers, which had been established by Horace, Eustace and Oswald Short in 1908 in Rochester, Kent, although in 1936 the company expanded its operations to Belfast, following a merger with the shipbuilder, Harland & Wolf, of Titanic fame. As the first company in the world to make production aeroplanes, Short Brothers soon specialised in building seaplanes, most notably the C Class Empire flying boats which flew on Imperial Airways routes across the British Empire. In 1936, the company was chosen by the Air Ministry to create the RAF’s first four engine heavy bomber, which had to have 3 gun turrets and be capable of carrying a maximum bomb load of 14000lb over a range of 2000 miles with a cruising speed of at least 230 mph at 15000ft. There was an additional specification that it should be able to carry 24 troops if required and have a wingspan of no more than 100ft, which had both a positive and negative effect on its performance. This meant that the designers had to use a wing, similar to that used on the famous Sunderland Flying Boat, which had a low aspect ratio and high induced drag, resulting in excellent manoeuvrability, but a limited operational ceiling compared with the later 4 engine bombers, such as the Lancaster and Halifax. Powered by 4 Bristol Hercules engines, the Stirling was significantly bigger than the Lancaster and Halifax (as indicated below) with the longest bomb bay of any bomber in WW2, although the design restricted the maximum bomb size to 2000lb, whereas the Lancaster could carry a range of bombs including the 22000lb “Grand Slam”, which was used towards the end of the war. Another major issue with the Stirling was its tendency to swing on take-off, which could be counteracted using differential power.
Despite its difficulties, the Stirling entered service in August 1940 with 7 Squadron, although the first operational mission did not take place until 10th February 1941, with Rotterdam as the target. Initially designed to have a crew of 7, this was frequently increased to 8 with the addition of a second pilot, especially during the early days of operation. While eventually outperformed by the Lancaster and Halifax in terms of speed and altitude capability, the Stirling was incredibly agile once in the air and capable of absorbing significant battle damage. The 15000ft cruising altitude compared unfavourably with the Lancaster, which had a maximum ceiling of 24500ft and a speed of 287 mph, although more experienced Stirling crews reported being able to achieve 18000ft. As for manoeuvrability, the Stirling was reputed to be able to out turn most WW2 fighters, except the Hurricane. However, concern over its performance and reliability persisted and this led to the Stirling being withdrawn from frontline service in November 1943. It continued to be used in a variety of important support roles, such as paratrooper carrier, glider tug and special operations, the most famous of which was the huge airborne assault undertaken in 1944 (Operation Market Garden). A total of 2383 Stirlings were built at several factories in the UK, including Rochester, South Marston, Longbridge and Belfast. By comparison, WW2 saw the production of 7377 Lancasters and 11462 Wellingtons. Sadly, there is not a single surviving Stirling anywhere in the world, although a group of enthusiasts, called the Stirling Project based in Cambridgeshire, is in the process of reconstructing the front section of the bomber, using salvaged and reengineered parts. It is hoped that the reconstruction will eventually go on display at an aviation museum.
Falconer, Jonathan, Short Stirling, 1939-48 (all marks) Owner’s Workshop Manual (Yeovil, Haynes Publishing, 2015)
AIR 27/1350 218 Squadron, April 1942
Smith, Steve, From St Vith to Victory, 218 (Gold Coast)Squadron and the Campaign Against Nazi Germany (Barnsley, Pen & Sword Books Ltd, 2015)