One aircraft was scrapped in 1994, and another was destroyed in the Air France Flight 4590 crash in 2000.
The two prototype aircraft were used to expand the flight envelope of the aircraft as quickly as possible and prove that the design calculations for supersonic flight were correct.
Changes to design include different wing planform, more fuel, different engine standard and different air intake systems.
The production aircraft were different in many ways from the original prototypes, necessitating re-examining certain areas to obtain certification.
British Airways had seven production aircraft in commercial service: As part of tenth-anniversary celebrations on 24 December 1985, British Airways photographed G-BOAA, G-BOAC, G-BOAF and G-BOAG formation flying for their publicity material.