First flown in 1969, the Concorde supersonic passenger jet airliner entered service in 1976 and continued flying for 27 years. It was one of two supersonic transports to have been operated commercially. It had a maximum speed over twice the speed of sound at Mach 2.04 (~2,500 km/h) at cruise altitude. Concorde also had a take-off speed of 220 knots (407 km/h).