Editing Tupolev Tu-144 (section)

==Reasons for failure and cancellation==

===Limited routes===
Only one commercial route, [[Moscow]] to Alma-Ata (now [[Almaty]]), was ever used and flights were limited to one a week, despite there being eight Tu-144S certified aircraft available and a number of other routes suitable for supersonic flights, suggesting that the Aeroflot decision-makers had little confidence in the Tu-144 commercial viability when passenger service began in 1977.{{sfn|Moon|1989|p=185}}

===Failure to acquire Western technology===
{{See also|Soviet industrial espionage of Concorde}}
In the late 1970s, Soviet insiders were intensely hopeful in conversations with Western counterparts of reintroducing Tu-144 passenger service for the [[1980 Summer Olympics|1980 Moscow Olympic games]], even perhaps for flights to Western Europe, given the aircraft's high visibility, but apparently the technical condition of the aircraft weighed against such re-introduction even for token flights.{{sfn|Moon|1989|pp=199–200}}

There were unprecedented Soviet requests for Western technological aid with the development of the Tu-144. In 1977, the USSR approached [[Lucas Industries]], a designer of the engine control system for Concorde, requesting help with the design of the electronic management system of the Tu-144 engines, and also asked BAC-Aérospatiale for assistance in improving the Tu-144 air intakes. (The design of air intakes' variable geometry and their control system was one of the most intricate features of Concorde, contributing to its fuel efficiency. Over half of the wind-tunnel time during Concorde development was spent on the design of air intakes and their control system.) In late 1978, the USSR requested a wide range of Concorde technologies, evidently reflecting the broad spectrum of unresolved Tu-144 technical issues. The list included de-icing equipment for the [[leading edge]] of the air intakes, fuel-system pipes and devices to improve durability of these pipes, drain valves for fuel tanks, fireproof paints, navigation and piloting equipment, systems and techniques for acoustical loading of airframe and controls (to test against acoustic fatigue caused by high jet-noise environment), ways to reinforce the airframe to withstand damage, firefighting equipment, including warning devices and lightning protection, emergency power supply, and landing gear spray guards (a.k.a. water deflectors or "[[Mudflap|mud flaps]]" that increase engine efficiency when taking off from wet airstrips).{{#tag:ref|It is claimed sometimes that in the absence of landing gear spray guard, engine thrust during takeoff from a wet airstrip can drop by as much as 10%. While the claim source requires verification for numbers, that is the purpose of Concorde's spray guards.|group=N}} These requests were denied after the British government vetoed them on the ground that the same technologies, if transferred, could be also employed in Soviet bombers.{{sfn|Moon|1989|pp=199–200}}{{rp|pages=199–200}}<ref>{{cite magazine |title=Technical Aid Sought for Tu-144 |magazine=Aviation Week & Space Technology |date=4 December 1978 |pages=26–27 |publisher=McGraw-Hill |url=https://archive.aviationweek.com/issue/19781204 |url-access=subscription |access-date=13 November 2023 |archive-date=29 September 2023 |archive-url=https://web.archive.org/web/20230929162304/https://archive.aviationweek.com/issue/19781204 |url-status=live }}</ref> Soviet approaches were also reported in British tabloids at the time, such as the ''[[Daily Mirror]]''.<ref name="dailymirror-19761111">{{cite news |last1=Stephens |first1=Peter |title=Concorde plea by Kremlin |url=https://www.newspapers.com/article/daily-mirror-concorde-plea-by-kremlin/135115591/ |access-date=13 November 2023 |work=[[Daily Mirror]] |date=11 November 1976 |archive-url=https://web.archive.org/web/20231113080736/https://www.newspapers.com/article/daily-mirror-concorde-plea-by-kremlin/135115591/ |archive-date=13 November 2023 |location=Paris, France |page=7 |url-status=live |issue=22,640 }}</ref>

===Compressor disc and other failures===
On 31 August 1980, Tu-144D (77113) suffered an uncontained compressor disc failure in supersonic flight which damaged part of the airframe structure and systems. The crew was able to perform an emergency landing at [[Engels-2]] strategic bomber base.<ref name="GordonRigmant2005" />{{rp|page=60}}<ref name="Chronology">{{cite book |last1=Bliznyuk |first1=Valentin |display-authors=etal |author-link1=Valentin Bliznyuk |title=Правда о сверхзвуковых пассажирских самолетах |trans-title=The Reality of Supersonic Passenger Airplanes |publisher=testpilot.ru |location=Moscow |language=ru |chapter=Приложение 1 - Хронология основных событий и история создания самолета Ту-144 |trans-chapter=Appendix 1 - Chronology of Major Events and the History of the Creation of the Tu-144 Aircraft |year=2000 |isbn=5-239-02044-2}}</ref>

On 12 November 1981, a Tu-144D's RD-36-51 engine was destroyed during bench tests, leading to a temporary suspension of all Tu-144D flights.<ref name="Chronology"/> It became the final blow, which resulted in the cancellation of the project by the Ministry of Aviation Industry and the Ministry of Civil Aviation.<ref name="AyzatullovaSudakov2020" />{{rp|page=91}}

One of the Tu-144Ds (77114, a.k.a. aircraft 101) suffered a crack across the bottom panel of its wing.<ref name="bliznyuk2000">{{cite book |last1=Bliznyuk |first1=Valentin |display-authors=etal |author-link1=Valentin Bliznyuk |title=Правда о сверхзвуковых пассажирских самолетах |trans-title=Reality of Supersonic Passenger Airplanes |year=2000 |publisher=testpilot.ru |location=Moscow |language=ru |url=https://www.testpilot.ru/review/sst/ |archive-url=https://web.archive.org/web/20231113130226/https://www.testpilot.ru/review/sst/ |archive-date=13 November 2023 |url-status=live  |isbn=5-239-02044-2}}</ref>{{rp|page=13}}

===Economic inefficiency===
Global trends facilitated the transition of jet transportation from a luxury available only to the elite, to a widespread form of mass transportation. Although the [[1973 oil crisis]] did not directly impact decision-making processes within the Soviet Union, the expansion of Soviet air travel in the late 1970s made the supply of aviation fuel a growth constraint, and it was obvious that potential Western buyers were heavily dissuaded by high fuel prices. By the late 1970s, Soviet promotional efforts shifted to the [[Ilyushin Il-86]], a more economically efficient [[jumbo jet]] that went on to become the country's flagship airliner.{{sfn|Moon|1989|pp=153–154}} Moon notes that in 1976, Aeroflot was promoting the Il-86 over the Tu-144, despite the latter's incipient and long-awaited entry into service.{{sfn|Moon|1989|pp=173,181}}

G.A. Cheryomukhin, an aerodynamics engineer who took part in the design and certification of Tu-144,<ref name="AyzatullovaSudakov2020" />{{rp|page=88}} wrote that the Ministry of Civil Aviation was concerned that the continuation and expansion of the SST's operation would have forced the Ministry to make significant long-term investments.<ref name="AyzatullovaSudakov2020" />{{rp|page=91}}

Moon concluded that economic efficiency alone would not have doomed the Tu-144 altogether; continuation of token flights for reasons of political prestige would have been possible, if only the aircraft itself would have allowed for it, but it did not.{{sfn|Moon|1989|pp=199–200}} The Tu-144 was to a large extent intended to be, and trumpeted as, a symbol of Soviet technological prestige and superiority.

===Tupolev design bureau and rivalry with Ilyushin===
Fridlyander and Moon point out that by the early 1970s, Tupolev's bureau had to work on other projects, including the [[Tupolev Tu-154|Tu-154]] and [[Tupolev Tu-204|Tu-204]] passenger aircraft, and the [[Tupolev Tu-22M|Tu-22M]] and [[Tupolev Tu-160|Tu-160]] bombers.<ref name="Fridlyander"/>{{sfn|Moon|1989|pp=185–186}} Despite large and high-priority resource investment in the Tu-144 development programme and the fact that a large part of the whole Soviet [[Research and development|R&D]] infrastructure was subordinated to the Tu-144 project, parallel project development overwhelmed the bureau causing it to lose focus and make design errors.<ref name="AyzatullovaSudakov2020" />{{rp|page=90}}

Alexander Poukhov, one of the Tu-144 design engineers who subsequently rose to be one of the bureau's senior designers, estimated in 1998 that the Tu-144 project was 10–15 years beyond the USSR's capabilities at that time.{{#tag:ref|Poukhov: "My opinion is that at that time, it was an aircraft that was ten or even fifteen years ahead of its time and the capabilities of the country", in an interview to PBS documentary ''Supersonic Spies''.<ref name="nova98" />|group=N}}

Moon suggests that Tupolev's difficulties in developing the Tu-144, together with a need to prioritize bomber development, prompted Soviet leaders to shift airliner development to the rival [[Ilyushin]] design bureau, which had recently introduced the successful [[Ilyushin Il-76|Il-76]] military transport and was developing the Il-86 to move much larger numbers of passengers at a much lower per-seat cost than the Tu-144. Moon contrasts the Ilyushin bureau's careful advance research into operating costs and its marketing surveys of Aeroflot customers with the "technocratic futurism" embodied by the Tu-144, suggesting that Soviet leaders recognized that the Il-86 better addressed real-world transportation needs in the Soviet Union and elsewhere.{{sfn|Moon|1989|pp=185–187}}