Royal Air Force and replacement by the F-35, the RAF Lossiemouth-based 15 (Reserve) Squadron (the Tornado Operational Conversion Unit) was disbanded in March 2017. Lightning: On 23 November 2015 it was announced that a total of 138 F-35Bs will be ordered. 617 (The Dambusters) Squadron officially reformed on 18 April 2018 as an RAF Lightning Squadron. The first four aircraft arrived at RAF Marham on 7 June 2018. The Sentry AEW1, based at RAF Waddington, provides airborne early warning to detect incoming enemy aircraft and to co-ordinate the aerial battlefield. The Sentinel R1 (formally known as ASTOR – Airborne STand-Off Radar) provides a
RAF Manston Others included RAF Greenham Common, RAF Aldergrove and RAF Machrihanish. For a number of years, the base operated as a Master Diversion Airfield, open 24 hours every day. Manston, uniquely in the UK, also had a 'foam carpet' crash landing system, where two tractors would pull tankers laying a metre thick layer of foam over a strip of runway, for aircraft with landing gear problems. RAF Manston was home to a helicopter search and rescue (SAR) flight from No. 22 Squadron RAF from 1961, operating Westland Whirlwind aircraft. The flight was withdrawn in 1969, but the outcry led to the