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 Prestwick March 2013 that RAF Prestwick would close by the end of 2013. Due to technological advances, there was no longer a requirement for two military area radar control centres in the United Kingdom.The unit subsequently closed on 6 December 2013, when the RAF Ensign was lowered for the final time, representing the end of a 77-year association between Ayrshire and the RAF. Prestwick's operations and thirty personnel were transferred to the RAF unit based in the NATS London Air Traffic Control Centre in Swanwick, Hampshire, forming a single military area radar unit. A small number of RAF personnel remained at