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
No. 342 Squadron RAF their sister squadron No. 88 Squadron to RAF Hartford Bridge. The squadron flew low-level bombing and strafing missions (nicknamed "hedgehopping"), over France and the Netherlands, in particular against V-1 bases in Northern France and selected sites connected with the preparation for D-Day. In October 1944 the squadron relocated to France from where it continued to support the Allied advance. In March/April 1945 the Bostons were replaced by B-25 Mitchells and the squadron relocated to the Netherlands. The squadron was transferred from RAF control to the French Air Force ( "Armée de l'Air" ) on 2 December 1945. No. 342 Squadron