No. 42 Squadron RAF  No. 42 Squadron of the Royal Air Force has served during World War I as an army co-operation squadron and during World War II in various roles. In recent years, it was the Operational Conversion Unit (OCU) for the Nimrod MR.2, based at RAF Kinloss, Moray, until the Nimrod MR2's retirement in 2010. Formed on 1 April 1916 from crews of 19 Squadron Royal Flying Corps at Filton, 42 Squadron spent the First World War flying reconnaissance sorties. Using BE2s (and later RE8s), the squadron spent time on both the Western Front and the Austro-Italian Front. On returning to England after the war, the squadron was disbanded at RAF Netheravon on 26 June 1919. On 14 December 1936 'B' flight of No. 22 Squadron RAF was expanded into a new No. 42 Squadron. In 1939 No. 42 Squadron was based at RAF Bircham Newton. Initially the unit was equipped with Vickers Vildebeests before re-equipping with Bristol Beauforts in January 1940. The squadron operated also a bomber unit in the Burma campaign flying Blenheims during 1942 and as a fighter-bomber unit flying Hurricanes during 1943. The squadron disbanded on 30 June 1945 but on the following day 146 Squadron was renumbered to No. 42 Squadron and flew Thunderbolts. The squadron fought on with these until the Burma campaign ended and thereafter the squadron disbanded on 30 December 1945 at Meiktela. On 1 October 1946 254 Squadron at RAF Thorney Island was renumbered to No. 42 Squadron. Equipped with Bristol Beaufighter, it was a strike unit in RAF Coastal Command until disbanded on 15 October 1947. On 28 June 1952, No. 42 Squadron was reformed, flying Avro Shackletons in the maritime reconnaissance role. The squadron converted to Nimrods in April 1971. The squadron served in Gulf 1 Operation Granby where one of its crew was credited with having achieved the highest number of "Assisted Kills", achieved operating in a High Air Threat environment. The same crew subsequently received the Arthur Barratt Memorial Award. Disbanded as a front-line unit in October 1992, it was later reformed as No. 42 (Reserve) Squadron at RAF Kinloss, Moray, taking over from No. 236 OCU as the Nimrod Operational Conversion Unit (OCU). The squadron flew its last Nimrod MR.2 flight on 30 March 2010, and was formally disbanded on 26 May 2011.