A prototype (OKB: izdeliye 044 - article 044[1]) first flew on 31 December 1968 near Moscow, two months before the similar Aérospatiale / British Aircraft Corporation Concorde. The Tu-144 first broke the speed of sound on 5 June 1969, and on 15 July 1969 it became the first commercial transport to exceed Mach two. The Tu-144 was introduced into passenger service on 1 November 1977, almost two years later than the Concorde, but was quickly withdrawn only after 55 scheduled passenger flights due to severe problems with aircraft safety and was not re-introduced to service.
The Tu-144 was Tupolev's only supersonic commercial airliner venture. Tupolev's other large supersonic aircraft were designed and built to military specifications. All these aircraft benefited from technical and scientific input from TsAGI, the Central Aerohydrodynamic Institute.
Although the Tu-144 was technically broadly comparable to Concorde, the Tu-144 lacked a passenger market within the Soviet Union and service was halted after only about 100 scheduled flights.
Paris Air Show crash
At the Paris Air Show on 3 June 1973, the development program of the Tu-144 suffered severely when the first Tu-144S production airliner (reg 77102) crashed.[7][8]
While in the air, the Tu-144 underwent a violent downwards maneuver. Trying to pull out of the subsequent dive, the Tu-144 broke up and crashed, destroying 15 houses and killing all six people on board the Tu-144 and eight more on the ground.
The causes of this incident remain controversial to this day. A popular theory was that the Tu-144 was forced to avoid a French Mirage chase plane which was attempting to photograph its canards, which were very advanced for the time, and that the French and Soviet governments colluded with each other to cover up such details. The flight of the Mirage was denied in the original French report of the incident, perhaps because it was engaged in industrial espionage. More recent reports have admitted the existence of the Mirage (and the fact that the Russian crew were not told about the Mirage's flight) though not its role in the crash. However, the official press release did state: "though the inquiry established that there was no real risk of collision between the two aircraft, the Soviet pilot was likely to have been surprised."[9]
Another theory claims that the black box was actually recovered by the Soviets and decoded. The cause of this accident is now thought to be due to changes made by the ground engineering team to the auto-stabilisation input controls prior to the second day of display flights. These changes were intended to allow the Tu-144 to outperform Concorde in the display circuit. Unfortunately, the changes also inadvertently connected some factory-test wiring which resulted in an excessive rate of climb, leading to the stall and subsequent crash.[10]
A third theory relates to deliberate misinformation on the part of the Anglo-French team. The main thrust of this theory was that the Anglo-French team knew that the Soviet team were planning to steal the design plans of Concorde, and the Soviets were allegedly passed false blueprints with a flawed design. The case, it is claimed, contributed to the imprisonment by the Soviets of Greville Wynne in 1963 for spying.[11][12] Wynne was imprisoned on 11 May 1963 and the development of the Tu-144 was not sanctioned until 16 July. In any case, it seems unlikely that a man imprisoned in 1963 could have caused a crash in 1973.
Operational service
The Tu-144S went into service on 26 December 1975, flying mail and freight between Moscow and Alma-Ata in preparation for passenger services, which commenced in November 1977 and ran a semi-scheduled service until the first Tu-144D experienced an in-flight failure during a pre-delivery test flight, and crash-landed with crew fatalities on 23 May 1978 [13]. The Aeroflot flight on 1 June 1978 was the Tu-144's 55th and last scheduled passenger service.
A scheduled Aeroflot freight-only service recommenced using the new production variant Tu-144D (Dal'nyaya - long range[14]) aircraft on 23 June 1979, including longer routes from Moscow to Khabarovsk made possible by the more efficient Kolesov RD-36-51 turbojet engines used in the Tu-144D version, which increased the maximum cruising speed to Mach 2.15.[15] Including the 55 passenger flights, there were 102 scheduled Aeroflot flights before the cessation of commercial service.
It is known that Aeroflot still continued to fly the Tu-144D after the official end of service, with some additional non-scheduled flights through the 1980s. One report showed that it was used on a flight from the Crimea to Kiev in 1987
(WIKIPEDIA)
No comments:
Post a Comment