XA847 was the first of three P.1Bs which followed two P.1As and was much closer in shape to the production Lightning design. Maiden flight 4.4.57 at Warton piloted by Roly Beamont; on 25.11.57 became the UK's first aircraft to exceed Mach 2. After a long career at Boscombe Down and Farnborough trialling various Lightning upgrades, retired to Henlow in 6.69 after 468 flights/205 hrs and placed on display at the RAF Museum in 1972 but ousted by a Lightning F.6 in 1988. Narrowly avoiding scrapping, passed into private hands and remains dismantled in Suffolk