The Bristol Model 188, nicknamed The ''Flying Pencil'' for it's overall appearance – was one of Great Britain's first Supersonic Aircraft, classed as an ''Experimental'' Model. Iy first flew in 1962. The Project was used to develop high-altitude, supersonic airframes which could be produced within the British manufacturing system (without having to rely on Imports). (3) such Model 188s were produced for testing. The primary issue with The Program being discontinued was due to the massive expenditure of high test fuel which was consumed by it's engines – just to achieve supersonic speed. A more efficient version was needed, which turned out to be too cost prohibive at the time.
Piloted by (1), The Model 188 was 78-feet in length with a modified swept-wingspan of 35-feet. Power was provided by (2) de Havilland Afterburning Turbojet Engines, capable of producing 10,000-IBF of Thrust each. Rated at a maximum speed of Mach 2 (1,200-mph), The Model 188 reached 40,000-feet in altitude on it's final test flight.