First supersonic airliner

The first airliner to achieve supersonic flight was the Soviet Union's Tupolev Tu-144. The prototype (airframe 044) made its maiden flight on 31 December 1968, and broke the sound barrier for the first time during a test flight on 5 June 1969.

In the mid-1960s, many leading technologists around the world were convinced that supersonic airliners (often referred to as SSTs, or "supersonic transports") were the future of international air travel. A three-way race began to be the first to field such an aircraft. The Tupolev Tu-144 was the Soviet Union's challenger, going up against the Anglo-French Concorde and the American Boeing 2707 (which ended up being cancelled in 1971 while still on the drawing board).

As a consequence of this competition, the first prototype version of the Tu-144 was rushed into production with relatively little mathematical modelling of its high-speed performance (at least compared to Concorde). The result was an aircraft that was extremely fast but had many aerodynamic and mechanical problems.

The tests had revealed that the Tu-144 prototype had a range of just 2,920 km (1,814 mi), far short of the 6,500 km range specified in the design brief. Larger fuel tanks were added to the production models which, in addition to numerous aerodynamic changes, increased the total weight from 150 to 190 tonnes (330,000–418,000 lb). These changes fixed the aircraft's low-speed control problems and reduced vibration from the engines, but the range problems never really went away.

The Tu-144S (the production model) had a reported cruising speed of around 2,330 km/h (1,450 mph; Mach 2.2) at 18,000 m (59,000 ft), allegedly rising to as much as 2,500 km/h (1,553 mph; Mach 2.35) under the right conditions. This meant it was faster than Concorde, which was limited to Mach 2.02 – around 2,150 km/h (1,335 mph) at 15,240 m (50,000 ft) – by a computerized autopilot to prevent long-term airframe damage. It's not clear whether the Tu-144's higher airspeeds would have dramatically shortened its lifespan as the 16 production aircraft were not in service long enough for issues to become apparent.

Despite breaking speed records, the Tupolev Tu-144 is generally regarded as a failure. Its NK-144 engines were unable to provide enough thrust for supersonic cruising speeds without the use of afterburners, meaning that the Tu-144 was extremely loud (a deafening 90-95 dB in the cabin) and had a much shorter operational range than its original design specification called for. Instead of the planned 6,500-km (4,038-mi) range, the Tu-144S could reportedly only manage around 3,500 km (2,174 mi) with a typical payload, making it unable to fly transatlantic routes.

The Tu-144 made its first trial flights with the Soviet national airline, Aeroflot, in 1974. Regular flights started on 26 December 1975, carrying mail between Moscow and Alma-Ata (present-day Almaty, Kazakhstan), passenger flights on the same route began on 1 November 1977 but were cancelled again on 31 May 1978. The immediate cause of the cancellation was a crash involving the second-generation model (the Tu-144D) during testing, but there were also serious misgivings at Aeroflot about operating this expensive and ultimately unnecessary service.

In the end the age of the SST never materialised. Concorde entered service in 1976, but the hoped-for high demand for its services wasn't there. It remained marginally profitable as a niche service on the busy transatlantic routes until its retirement in 2003, but there was not enough of a market to support the construction of any more SSTs after Concorde's initial run of 20 aircraft.