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. The Squadron moved to bases in France in February 1945, and then to RAF Gutersloh in Germany in December 1945. It provided courier services between Blackbushe and Nuremberg in support of the Nuremberg Trials before it was disbanded on 7 November 1947. Jet bombers On 21 September 1953 the squadron was reformed at RAF Scampton as a bomber unit with the English Electric Canberra as part of a four-squadron Canberra wing. The Scampton wing was dispersed in 1955 to allow Scampton to be redeveloped as a base for V-bombers, with 21 Squadron moving to RAF Waddington in May 1955. It was involved in many overseas detachments, and was part of the forces involved in the Suez operation of 1956. The squadron was disbanded on 30 June 1957 at Waddington. On 1 October 1958, 542 Squadron, based at RAF Upwood and equipped with the Canberra B6 which were used to collect airborne particle samples in support of nuclear weapons testing, was re-numbered as 21 Squadron. The squadron, with a detachment at Laverton, Western Australia continued to support British nuclear testing. The squadron was disbanded again on 15 January 1959. Transport squadron Formation again on 1 May 1959 at RAF Benson saw a completely different role for the squadron: it was equipped with the Scottish Aviation Twin Pioneer as a light transport squadron. It moved to Kenya in September that year, being based at RAF Eastleigh, Nairobi. It