'Oyster' was the British daylight air attack by Air Marshal Sir Arthur Harris’s RAF Bomber Command on the Philips radio factory at Eindhoven in the German-occupied Netherlands (6 December 1942).
The raid was carried out by all of the operational day bomber squadrons of Air Vice Marshal A. Lees’s No. 2 Group under the command of Wing Commander J. E. Pelly-Fry, and was directed against Eindhoven in the German-occupied Netherlands as the Philips radio and valve factory located in this city was producing large quantities of important electrical and electronic materials needed by the German forces.
Some 93 bombers were committed to the raid, these comprising 47 Lockheed Ventura aircraft of Nos 21, 464 and 487 Squadrons, 36 Douglas Boston aircraft of Nos 88, 107 and 226 Squadrons, and 10 de Havilland Mosquito aircraft of Nos 105 and 139 Squadrons. One of the last was a photo-reconnaissance aeroplane rather than a bomber. One squadron equipped with North American Mitchell bombers was withdrawn from the planned force during the training period because its crews had not gained enough experience on this new aircraft type.
Eindhoven is situated some 70 miles (115 km) inland from the Dutch coast, and at the time was well beyond the range of any available escort fighter type. In an effort to draw off German fighter forces, therefore, a large diversion against Lille was flown by 84 Boeing B-17 Flying Fortress bombers of the USAAF escorted by Supermarine Spitfire fighters of RAF Fighter Command, and a British squadron equipped with the new North American P-51 Mustang fighter carried out a sweep along the Dutch coast to give indirect support.
The 'Oyster' raid was flown at low level and in clear weather conditions, the bombing was accurate, and severe damage was caused to the factory, which was situated in the middle of the town. Because the raid was deliberately carried out on a Sunday, there were few casualties in the factory but several bombs fell in nearby streets and 148 Dutch civilians as well as seven German soldiers were killed. The factory did not re-establish full production for six months.
The losses to the attacking force were severe: nine Ventura, four Boston and one Mosquito aircraft were lost over the Netherlands or over the North Sea. This represented a 15% loss rate, and the Ventura, which was the type with the poorest performance, suffered 19% losses. Three more aircraft crashed or force-landed in England, and most of the other aircraft were damaged, no fewer than 23 of them by bird strikes.