SUPERSONIC AIRCRAFT FLY FASTER than the speed of sound (Mach 1). There are many supersonic military aircraft, but only two supersonic passenger-carrying aircraft (also called SSTs, or
supersonic transports) have been produced: the Russian Tu-144, and the Concorde, produced jointly by Britain and France. The Tu-144 was withdrawn in 1978, after only seven months in service. The
Concorde remained in service from 1976 until 2003, with a break for modifications from July 2000 until October 2001. Its features included a droop nose, which lowered during takeoff and landing to aid visibility from the cockpit; the pumping of fuel between forward and aft trim tanks helped stabilize the aircraft. The Concorde had a narrow fuselage and short span wings to reduce drag during supersonic flight. Its noisy turbojet engines with afterburners enabled it to carry 100 passengers at a cruising speed of Mach 2 at 50,000-60,000 ft (15,000-18,000 m). Once an aircraft is flying faster than Mach 1, it produces a continuous air-pressure wave, which is heard as a “sonic boom.”
