The Stirling had a slow introduction to service. The first Mk I Series I aircraft was delivered to No. 7 Squadron on 3 August 1940. However the disappointing performance of the aircraft and the slow pace of deliveries meant that it would be six months before the squadron made its first raid.
Understandably there was a great deal of political pressure for the first raid by a British four engined bomber. Churchill was keen on an attack on Berlin, but wiser counsels prevailed and the first Stirling raid was an attack on oil storage tanks at Rotterdam, launched on 10-11 February 1941. Three Stirlings of No. 7 Squadron dropped 24,000 lbs of bombs on the target and returned without lose. Although only a small raid it did demonstrate the potential of the heavy bombers – it would have taken twice the number of Wellingtons to carry the same bomb load to Rotterdam. Berlin still remained a target for the Stirling. A first attempt to reach the German capital failed on 9 April, but on 17-18 April a single Stirling finally reached Berlin, dropping 8,500 lb of bombs.
During 1941 the Stirling made a series of daylight raids on coastal targets. These were costly and achieved little, but as there were only two Stirling squadrons for most of the year this can hardly be considered a surprise.
The Stirling was briefly used on the Circus operations during the summer of 1941. These were raids into occupied Europe designed to force the Luftwaffe to respond. Earlier fighter sweeps without bombers had been ignored. The Stirling was not an ideal aircraft for these missions – in one month of Circuses five were destroyed and eleven damaged, mostly by anti-aircraft fire. It was realised that these raids were a waste of the new four engined heavies, and the Stirling was quickly replaced by two engined bombers.
The presence of the large German ships Scharnhorst and Gneisenau at Brest
Scharnhorst provided the RAF with an irresistible and important target. The Stirling was involved in raids on the German ships in April, July, October and December 1941, suffering a series of losses without inflicting any real damage on the ships, which later made the famous “channel dash” to relative safety in German waters.
Italy became a target in 1941. The Stirling had the range to reach northern Italy from bases in Britain while carrying a reasonable bomb load. However, the aircraft did not always have the altitude to fly over the alps, and so on several occasions Stirlings were reported to have flow through the Alpine passes to reach Italy. Stirling squadrons returned to Italy late in 1942 to support the invasion of North Africa, once again flying from Britain. By 1943 aircraft involved in these raids also had the option of flying on to North Africa if they could not return to Britain.
The Stirling took part in all three of the 1,000 bomber raids on 1942. The first of these was against Cologne, on 30 May. The new head of Bomber Command, Air Chief Marshal Sir Arthur Harris, intended these raids to prove the value of his heavy bomber force. Stirlings made up 88 of the 1,046 aircraft that took part in the raid, with 73 reporting success. The second raid, against Essen on 1-2 June involved 78 Stirlings, the third, against Bremen on 25-26 June only 72. The 1,000 bomber raids succeeded in that they achieved Harris’s main aim of justifying his heavy bomber force, although somewhat smaller raids would remain more normal.
1942 saw the formation of the Pathfinder squadrons. Four squadrons, one for each bomber in use with Bomber Command in 1942 were selected to lead the main bomber stream on its raids. They would identify the target and mark it with flares allowing the main force to make more accurate attacks. The Pathfinder force would become increasingly important over the next three years. No. 7 Squadron was selected to be the Stirling squadron that moved to the Pathfinders.
The Stirling played an important role in the dropping of mines in coastal waterways used by the Germans. Here the narrow bomb bay was not a problem. As the standard mine was a slim 1,500 lb weapon, ideally suited for use in the Stirling. From March 1942 until the end of the war the Stirling dropped 20,000 mines in these shipping channels. These operations were code named Gardening. The most important of these routes were probably those that passed through Danish waters, linking the Baltic and the North Sea. At first these mine were dropped at low level, to avoid damage to the mines. However, this did run the risk of the aircraft hitting the sea, as altitude was hard to judge over water. Later on experiments proved that the mines could be safely dropped from higher altitude without damage, making the missions much safer.
The low service ceiling of the Stirling was its main weakness as a bomber. While heavy flak threatened all Allied bombers operating at 20,000 feet, three thousand feet lower the Stirling was just that but more vulnerable. The lack of any downward firing guns also contributed to a heavy lose rate. The low operating altitude of the Stirling also made it hard for the type to cooperate with other Bomber Command aircraft, who would often be dropping their bombs through the lower flying Stirling formations. The Stirling was withdrawn from the main bomber force after a last raid against Berlin on 22-23 November 1943. The Stirling remained in Bomber Command service for another year, performing mine-laying duties along the coast of occupied Europe and electronic counter measures to aid the main bomber stream.
As the bomber the Stirling was at best fourth in importance for Bomber Command. It dropped only 27,821 tons of bombs, compared to 41,800 for the Wellington, 227,000 for the Halifax and an amazing 608,612 tons for the Lancaster. However it was also responsible for dropping 20,000 mines into German controlled waters.
During 1944 No. 199 Squadron joined 100 Group carrying out electronic counter measures against the German air defences. The Stirling was used to carry Mandrel equipment, used to jam or overwhelm German radar and radio systems. Mine dropping operations also continued in 1944, and the Stirling did not make its final bombing raid until 7-8 March 1945, during the Allied advance into Germany.