On the same day a new 21 Squadron was formed at RAF Bodney, still with the Blenheim, but re-equipped a few months later with the Lockheed Ventura. It was the first RAF squadron to use the Ventura, moving to RAF Methwold on 1 November. It flew its first operational mission using the Ventura, a low-level attack by three aircraft on railway lines near Hengelo in the Netherlands, on 3 November. On 6 December it took part in Operation Oyster, a large-scale attack by 2 Group on the Philips works at Eindhoven, with three of its aircraft being lost. The aircraft was never really suitable for the squadron's activities and they were replaced by October 1943 with the de Havilland Mosquito, having flown its last missions using the Ventura (and the last Ventura operations by 2 Group) on 9 September. The squadron turned to night raids on continental Europe; and from the end of 1943, like the rest of 2 Group, largely concentrated on Operation Crossbow, the campaign of attacks against V-1 flying bomb sites. The allied invasion of Normandy in June 1944 saw 2 Group's Mosquito squadrons, including 21 Squadron, employed on night-time interdiction missions to delay the flow of German troops to oppose the invasion. The squadron also carried out precision daylight raids including involvement in Operation Jericho on 18 February 1944 (where its aircraft served as a reserve force that did not need to drop their bombs), a notable attack on Gestapo headquarters at Aarhus in Denmark on 31 October 1944 and in Operation Carthage, against Gestapo headquarters in Copenhagen.