User:KreyszigB/lightning

From 1953 onwards, the first three prototype aircraft were hand-built at Samlesbury. These aircraft had been assigned the aircraft serials WG760, WG763, and WG765 (the static airframe). The prototypes were powered by un-reheated Armstrong Siddeley Sapphire turbojets, as the selected Rolls-Royce Avon engines which would power subsequent production aircraft had fallen behind schedule due to their own development problems. Due to the limited internal space of the fuselage the fuel capacity was relatively small, giving the prototypes an extremely limited endurance, and the narrow tyres housed in the thin wings would rapidly wear out. Outwardly, the prototypes looked very much like the production series, but they were distinguished by the rounded-triangular intakes, short fins and lack of operational equipment. On 9 June 1952, it had been decided that there would be a second phase of prototypes built to develop the aircraft towards achieving 2.0 Mach; these were designated P.1B while the initial three prototypes were retroactively reclassified as P.1A.

P1B was a significant improvement on P1A. While it was similar in aerodynamics, structure and control systems, it incorporated extensive alterations to the forward fuselage, reheated Rolls Royce Avon R24R engines, a conical centre body inlet cone, variable nozzle reheat and provision for weapons systems integrated with the ADC and AI.23 radar. Three P1B prototypes were built, assigned serials XA847, XA853 and XA856

In May 1954, WG760 and its support equipment were moved to RAF Boscombe Down for pre-flight ground taxi trials; on the morning of 4 August 1954, WG760, piloted by Roland Beamont, flew for the first time from Boscombe Down. One week later, WG760 officially achieved supersonic flight for the first time, having exceeded the speed of sound during its third flight.

During its first flight, WG760 had unknowingly exceeded 1 Mach, but due to position error the Mach meter only showed a maximum of 0.95 Mach. The occurrence was noticed during flight data analysis a few days later.

While WG760 had proven the P.1 design to be viable, it was limited to 1.51 Mach due to directional stability limits. In May 1956, the P.1 received the Lightning name, which was said to have been partially selected to reflect the aircraft's supersonic capabilities.

P1B (XA847) first fle w from Warton on the 4 April 1957.on 25 November 1958, IT became the first British aircraft to fly at Mach 2.