Fighter-bomber “Whirlibomber” of No. 137 Squadron RAF, March 1943
In late 1942, the Whirlwind aircraft was modified to serve as a bomber, taking on a similar role to the Hurribomber in launching attacks on enemy-occupied areas using both bombs and cannons, during both day and night missions. Each aircraft could carry one 250 or 500-lb (113 or 227-kg) bomb beneath each wing, and the adapted versions became informally known as “Whirlibombers.” The idea to equip the Whirlwind with bomb racks was first suggested in September 1941 by Squadron Leader T. Pugh, D.F.C., the commander of No. 263 Squadron. However, the first modification wasn’t completed until July 21, 1942, when one of the squadron’s aircraft was finally fitted to carry bombs.
The first mission using the “Whirlibomber” took place on September 9, 1942, as a test run. During this operation, two sections of Whirlwinds, escorted by Spitfires, targeted four armed trawlers moving from Cap de la Hague, near Cherbourg, towards Alderney. The mission was a success, with two of the trawlers being sunk. Bomb sights were not used for these operations; instead, the Whirlwinds bombed from altitudes as low as 50 feet (15 meters). Because of this low-level approach, delayed-action fuses were selected for the bombs. When carrying bombs, the aircraft had a tendency to tilt to the left during dives, and the pilots experienced aileron snatch at high speeds. It was recommended that both bombs be dropped simultaneously during low-altitude attacks, but for those wishing to make two bombing passes, it was advised to drop the left-wing bomb first.
The two Whirlwind squadrons continued their bombing raids, employing both bombs and cannons, until they were replaced by Typhoons in 1943. No. 263 Squadron primarily focused on the Brest and Cherbourg Peninsulas and the Western Approaches, while No. 137 Squadron, stationed at Manston, covered the English Channel and northern France. Railway lines were especially visible in moonlight, and the smoke from trains made them easy targets. Whirlwinds were highly effective in these operations, with their four 20-mm Hispano cannons proving more than sufficient for the job. For example, one pilot from No. 137 Squadron managed to destroy four locomotives in a single sortie.
During the first six months of their fighter-bomber operations, No. 137 Squadron was responsible for destroying or damaging thirty-seven freight trains – sixteen during nighttime missions and the rest in daylight. While daytime raids focused solely on freight trains, nighttime missions expanded to include passenger trains, as only Germans were allowed to travel by night in the occupied territories. Enemy airfields were also frequent targets for low-altitude attacks by the “Whirlibombers.”