Tu-144, the world's first commercial supersonic aircraft, surpassing Mach 2, went into service.
A supersonic aircraft is an aircraft capable of supersonic flight, that is, flying faster than the speed of sound (Mach number 1). Supersonic aircraft were developed in the second half of the twentieth century. Supersonic aircraft have been used for research and military purposes, but only two supersonic aircraft, the Tupolev Tu-144 (first flown on December 31, 1968) and the Concorde (first flown on March 2, 1969), ever entered service for civil use as airliners. Fighter jets are the most common example of supersonic aircraft.
The aerodynamics of supersonic flight is called compressible flow because of the compression associated with the shock waves or "sonic boom" created by any object traveling faster than sound.
Aircraft flying at speeds above Mach 5 are called hypersonic aircraft.
The Tupolev Tu-144 (Russian: Tyполев Ту-144; NATO reporting name: Charger) is a Soviet supersonic passenger airliner designed by Tupolev in operation from 1968 to 1999.The Tu-144 was the world's first commercial supersonic transport aircraft with its prototype's maiden flight from Zhukovsky Airport on 31 December 1968, two months before the British-French Concorde. The Tu-144 was a product of the Tupolev Design Bureau, an OKB headed by aeronautics pioneer Aleksey Tupolev, and 16 aircraft were manufactured by the Voronezh Aircraft Production Association in Voronezh. The Tu-144 conducted 102 commercial flights, of which only 55 carried passengers, at an average service altitude of 16,000 metres (52,000 ft) and cruised at a speed of around 2,200 kilometres per hour (1,400 mph) (Mach 2). The Tu-144 first went supersonic on 5 June 1969, four months before Concorde, and on 26 May 1970 became the world's first commercial transport to exceed Mach 2.Reliability and developmental issues, together with repercussions of the 1973 Paris Air Show Tu-144 crash and rising fuel prices, restricted the viability of the Tu-144 for regular use. The Tu-144 was introduced into passenger service with Aeroflot between Moscow and Almaty on 26 December 1975, but withdrawn less than three years later after a second Tu-144 crashed on 23 May 1978. The Tu-144 remained in commercial service as a cargo aircraft until the cancellation of the Tu-144 program in 1983. The Tu-144 was later used by the Soviet space program to train pilots of the Buran spacecraft, and by NASA for supersonic research until 1999. The Tu-144 made its final flight on 26 June 1999 and surviving aircraft were put on display across the world or into storage.