No. 617 Squadron RAF No. 617 Squadron RAF Number 617 Squadron is a Royal Air Force aircraft squadron, based at RAF Marham in Norfolk. It is commonly known as the "Dambusters", for its actions during Operation Chastise against German dams during the Second World War. In the early 21st century it operated the Tornado GR4 in the ground attack and reconnaissance role until being disbanded in the spring of 2014. The squadron reformed on 17 April 2018, and was equipped at RAF Marham during summer 2018 with the F-35 Lightning II, becoming the UK's first squadron with this advanced V/STOL type. According to the
No. 421 (Reconnaissance) Flight RAF were issued to 421 Flight and the Hurricanes went to other squadrons. No. 421 (Reconnaissance) Flight RAF No. 421 (Reconnaissance) Flight was a specialist RAF fighter flight created on 21 September 1940 to patrol the Channel and provide early warning of the types of incoming Luftwaffe raids from occupied France. It was later expanded to full squadron strength and renumbered as No. 91 Squadron on 11 January 1941. Its role led to its pilots being nicknamed "Jim Crows". In late September 1940, Air Chief Marshal Hugh Dowding was faced with two problems. The first was a change in Luftwaffe tactics.