No. 54 Squadron (sometimes written as No. LIV Squadron) is a squadron of the Royal Air Force. It is based at RAF Waddington, England. On 1 September 2005 it took on the role of Intelligence, Surveillance and Reconnaissance (ISR) Operational Conversion Unit, responsible for training all RAF crews assigned to the E-3D Sentry AEW1 and the Nimrod R1 and the Sentinel R1 as well as running the Qualified Weapons Instructor Intelligence, Surveillance and Reconnaissance Course (QWI ISR). The squadron was previously a SEPECAT Jaguar strike fighter unit, operating from RAF Coltishall, until it was disbanded on 11 March 2005. Since September 2005 the unit has been formally titled 54(Reserve) Squadron, until the (Reserve) nameplate was removed from all training squadrons in 2018.