View source for Tupolev Tu-144

{{Short description|Soviet supersonic passenger airliner}}
{{Use dmy dates|date=March 2024}}
{{Infobox aircraft
 |name= Tu-144
 |image= Tupolev TU-144 (6060104119).jpg
 |image_caption= An [[Aeroflot]] Tupolev Tu-144 taking off
 |aircraft_type= [[Supersonic airliner]]
 |national_origin = [[Soviet Union]]
 |design_group= [[Tupolev]] [[OKB]]
 |manufacturer= [[Voronezh Aircraft Production Association]]
 |first_flight= 31 December 1968<ref name="GordonRigmant2005">{{cite book |last1=Gordon |first1=Yefim |last2=Rigmant |first2=Vladimir |author-link1=Yefim Gordon |title=Tupolev Tu-144 |year=2005 |publisher=Midland |location=Hinckley, Leicestershire, UK |isbn=978-1-85780-216-0 }}</ref>{{rp|page=76}}
 |introduction= 26 December 1975<ref name="GordonRigmant2005" />{{rp|page=76}}
 |status= Retired from passenger service (1978) <br /> Retired from commercial service (1983) <br /> Retired (1999)
 |primary_user= [[Aeroflot]]
 |more_users= [[Ministry of Aviation Industry (Soviet Union)|Ministry of Aviation Industry]]<br />[[NASA]]
 |produced= 1967–1983
 |number_built= 16
 |variants=
}}

The '''Tupolev Tu-144''' ({{langx|ru|Tyполев Ту-144}}; [[NATO reporting name]]: '''Charger''') is a [[Soviet]] [[supersonic airliner|supersonic passenger]] [[airliner]] designed by [[Tupolev]] in passenger operation from 1978 to 1983.<ref name="CNN-20170928">{{cite news |url=https://www.cnn.com/style/article/tupolev-tu-144-concordski/index.html |title=How the Soviet Concorde crashed and burned |last=Prisco |first=Jacopo |date=28 September 2017 |work=[[CNN|CNN Style]] |access-date=19 January 2019 |archive-url=https://web.archive.org/web/20211110085314/https://www.cnn.com/style/article/tupolev-tu-144-concordski/index.html |archive-date=10 November 2021 |url-status=live}}</ref>

The Tu-144 was the world's first commercial supersonic transport aircraft with its [[prototype]]'s [[maiden flight]] from [[Zhukovsky International Airport|Zhukovsky Airport]] on 31 December 1968, two months before the British-French [[Concorde]].<ref name="GordonRigmant2005" />{{rp|page=76}}<ref name="Tu144BeatsConcorde">{{Cite web | url = https://www.flightglobal.com/news/articles/retrospective-tu-144-beats-concorde-to-first-flight-454704/ | title = Retrospective: Tu-144 beats Concorde to first flight | author = David Kaminski-Morrow | website = FlightGlobal | date = 31 December 2018 | publisher = Reed Business Information Limited | access-date = 13 February 2019 | archive-date = 14 February 2019 | archive-url = https://web.archive.org/web/20190214061517/https://www.flightglobal.com/news/articles/retrospective-tu-144-beats-concorde-to-first-flight-454704/ | url-status = live }}</ref> 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]].<ref name="GordonRigmant2005" />{{page needed|date=December 2021}} The Tu-144 conducted 102 [[commercial flight]]s, of which only 55 carried passengers, at an average service altitude of {{convert|16000|m|ft}} and cruised at a speed of around {{convert|2200|km/h|mph}} ([[Mach number|Mach]] 2).<ref name="bbc-20171018">{{cite news |last=Dowling |first=Stephen |title=The Soviet Union's flawed rival to Concorde |url=https://www.bbc.com/future/story/20171018-the-soviet-unions-flawed-rival-to-concorde |date=18 October 2017 |work=[[BBC]] |access-date=7 August 2019 |archive-url=https://web.archive.org/web/20211110085319/https://www.bbc.com/future/article/20171018-the-soviet-unions-flawed-rival-to-concorde |archive-date=10 November 2021 |url-status=live}}</ref><ref name="tupolev.ru">{{Cite web |url=http://www.tupolev.ru/en/aircrafts/tu-144 |title=Tu-144 – Туполев |trans-title=Tu-144 – Tupolev |access-date=13 September 2014 |archive-url=https://web.archive.org/web/20180817161428/http://www.tupolev.ru/en/aircrafts/tu-144 |archive-date=17 August 2018 |url-status=dead}}</ref> 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.<ref name="tupolev.ru" />

Reliability and developmental issues restricted the viability of the Tu-144 for regular use; these factors, together with repercussions of the [[1973 Paris Air Show Tupolev Tu-144 crash|1973 Paris Air Show Tu-144 crash]], projections of high operating costs, and rising fuel prices and environmental concerns outside the Soviet Union, caused foreign customer interest to wane.{{sfn|Moon|1989|pp=168–170}} The Tu-144 was introduced into commercial service with [[Aeroflot]] between [[Moscow]] and [[Almaty|Alma-Ata]] on 26 December 1975 and starting 1 November 1977 passenger flights began; it was withdrawn less than seven months later after [[1978 Yegoryevsk Tu-144 crash|a new Tu-144 variant crash-landed]] during a test flight on 23 May 1978. The Tu-144 remained in commercial service as a [[cargo aircraft]] until the cancellation of the Tu-144 programme in 1983. The Tu-144 was later used by the [[Soviet space program]]me to train pilots of the [[Buran (spacecraft)|Buran]] spacecraft, and by [[NASA]] for a supersonic research programme from June 1996 to April 1999. The Tu-144 made its final flight on 26 June 1999 and surviving aircraft were put on display in Russia, the former Soviet Union and Germany, or into storage.

==Background==
{{Broader|Supersonic transport#History}}
Given the vast size of the Soviet Union, supersonic travel was seen as economically feasible, especially for government employees travelling between Moscow and Siberian cities. Flying was the only practical alternative to week-long rail journeys, and supersonic transport could significantly cut travel times. While the idea of SSTs was controversial in the West due to noise and environmental pollution concerns, the Soviet Union planned to continue with their development, largely for its long Siberian and Central Asian routes. With ample airspace, flight corridors were likely to avoid built-up areas. Even if international landing rights were not granted, the Tu-144 could still be used for domestic and regional flights.<ref name="nyt73">{{cite news |last=Louis |first=Victor |title=Their Very Own SST |url=https://www.nytimes.com/1973/06/02/archives/their-very-own-sst.html |newspaper=[[The New York Times]] |date=2 June 1973 |archive-url=https://web.archive.org/web/20230531003833/https://www.nytimes.com/1973/06/02/archives/their-very-own-sst.html |archive-date=31 May 2023 |url-status=live}}</ref>

Aeroflot, the flag carrier of the Soviet Union, had an extensive network of interconnected airfields and increasing international reach, with hopes of extending flights to Sydney, Australia. Initial estimates suggested that 20 Tu-144s would suffice for Aeroflot's domestic and international needs.<ref name="nyt73" />

Given the geopolitical climate during the Cold War period, the Soviet Union was intent on not just matching, but surpassing Western advancements, particularly in aerospace technology. The idea of the West getting ahead and leaving the Soviet Union behind was unthinkable. The directive from [[Nikita Khrushchev]], the leader of the Soviet Union at that time, was clear: not only prevent the West from getting ahead, but also compete fiercely, even to the extent of leapfrogging their technological advancements, if necessary.<ref name="nova98">{{cite web |title=NOVA "Supersonic Spies" Transcript |url=https://www.pbs.org/wgbh/nova/transcripts/2503supersonic.html |website=[[PBS]] |date=27 January 1998 |archive-url=https://web.archive.org/web/20231105053428/https://www.pbs.org/wgbh/nova/transcripts/2503supersonic.html |archive-date=5 November 2023 |url-status=live}}</ref>
The aircraft was seen as a formidable challenge to the United States' dominance in the field of civil aviation.<ref name="nyt73"/>

==Development==
[[File:Tu-144-schoenefeld.jpg|thumb|Tu-144 prototype in June 1971, [[Berlin Schönefeld Airport]] ]]
[[File:Aircraft Mig-21I under the wing of the plane Tu-144 (9678535680).jpg|thumb|[[List of Mikoyan-Gurevich MiG-21 variants#Modernisation – generation three (1968–1972)|MiG-21I]] ''Analog'', used as a [[Testbed aircraft|testbed]] for the Tu-144's wing]]
[[File:Aeroflot Tupolev Tu-144 1977 Volpati-1.jpg|thumb|View of the front of the Tu-144, with the distinctive retractable [[canard (aeronautics)#Variable geometry|moustache canards]] deployed and [[Droop nose (aeronautics)|drooped nose]]]]
[[File:Aeroflot Tupolev Tu-144 Paris Air Show 1975 Gilliand.jpg|thumb|[[Aeroflot]] Tu-144 at the [[Paris Air Show]] in 1975.]]
The [[Government of the Soviet Union|Soviet government]] published the concept of the Tu-144 in an article in the January 1962 issue of the magazine ''Technology of Air Transport''.{{Script needed inline|date=June 2023|reason=This appears to reference a Soviet publication, but it's unclear which one.}} The air ministry started development of the Tu-144 on 26 July 1963, 10 days after the design was approved by the [[Council of Ministers of the Soviet Union|Council of Ministers]]. The plan called for five flying prototypes to be built in four years, with the first aircraft to be ready in 1966.

Despite the similarity in appearance of the Tu-144 to the Anglo-French supersonic aircraft (which earned it the nickname "Concordski"),<ref name="cnn-20190710">{{cite news |last=Prisco |first=Jacopo |date=10 July 2019 |title=Concordski: What ever happened to Soviets' spectacular rival to Concorde? |publisher=CNN |url=https://edition.cnn.com/style/article/tupolev-tu-144-concordski/index.html |access-date=15 February 2018 |archive-date=29 December 2020 |archive-url=https://web.archive.org/web/20201229050337/https://edition.cnn.com/style/article/tupolev-tu-144-concordski/index.html |url-status=live }}</ref> there were significant differences between the two aircraft. The Tu-144 is bigger and faster than the Concorde (M2.15 vs. M2.04). Concorde used an electronic engine control package from [[Lucas Industries plc|Lucas]], which Tupolev was not permitted to purchase for the Tu-144 as it could also be used on military aircraft. Concorde's designers used fuel as coolant for the cabin air conditioning and for the hydraulic system (see [[Concorde#Heating problems|Concorde]] for details). Tupolev also used fuel/hydraulic [[heat exchanger]]s, but used cooling turbines for the cabin air.<ref name="GordonKomissarovRigmant2015" />{{rp|p.187}}

The Tu-144 prototype was a full-scale demonstrator aircraft with the very different production aircraft being developed in parallel. The [[List of Mikoyan-Gurevich MiG-21 variants#Modernisation – generation three (1968–1972)|MiG-21I]] (1968; Izdeliye 21–11; "Analog") I = Imitator ("Simulator") was a [[Testbed aircraft|testbed]] for the wing design of the Tu-144 but came too late to provide inputs for the first prototype. The findings of the MiG-21I led to the completely redesigned wing of the following aircraft.<ref>[http://www.airwar.ru/enc/xplane/foton.html Foton] {{Webarchive|url=https://web.archive.org/web/20230613063023/http://www.airwar.ru/enc/xplane/foton.html |date=13 June 2023 }}, airwar.ru</ref> While both Concorde and the Tu-144 prototype had [[ogival delta]] wings, the Tu-144's wing lacked Concorde's conical [[Camber (aerodynamics)|camber]]. Production Tu-144s replaced this wing with a [[double delta]] wing including spanwise and chordwise camber.<ref name="GordonKomissarovRigmant2015">{{cite book|last1=Gordon |first1=Yefim |author-link1=Yefim Gordon |last2=Komissarov |first2=Dmitiry |first3=Vladimir |last3=Rigmant |title=Tupolev Tu-144 - The Soviet Supersonic Airliner |publisher=Schiffer Publishing Ltd |location= Manchester, UK |date=2015 |isbn=978-0-7643-4894-5}}</ref>{{rp|page=187}}

They also added two small retractable surfaces called a [[Canard (aeronautics)#Variable geometry|moustache canard]], with fixed double-slotted [[leading-edge slat]]s and retractable double-slotted [[Flap (aeronautics)|flaps]]. These were fitted just behind the cockpit and increased [[lift (force)|lift]] at low speeds.

Moving the [[elevon]]s downward in a delta-wing aircraft increases the lift, but also pitches its nose downward. The canards cancel out this nose-downwards [[moment (physics)|moment]], thus reducing the landing speed of the production Tu-144s to {{convert|315|-|333|km/h|mph kn|abbr=on}}.<ref name="TU-144 Ground-Effect Characteristics">{{cite tech report |last1=Curry |first1=Robert E. |last2=Owens |first2=Lewis R. |date=October 2003 |title=Ground-Effect Characteristics of the Tu-144 Supersonic Transport Airplane |publisher=[[Armstrong Flight Research Center|NASA Dryden Flight Research Center]] |id=TM-2003-212035 |url=http://www1.nasa.gov/centers/dryden/pdf/88750main_H-2510.pdf |archive-url=https://web.archive.org/web/20061014045730/http://www.nasa.gov/centers/dryden/pdf/88750main_H-2510.pdf |archive-date=14 October 2006 |url-status=dead |access-date=25 January 2011}}</ref><ref name="Tu-144 Piloted Evaluation">{{cite tech report |last1=Rivers |first1=Robert A. |last2=Jackson |first2=E. Bruce |last3=Fullerton |first3=C. Gordon |author-link3=C. Gordon Fullerton |last4=Cox |first4=Timothy H. |last5=Princen |first5=Norman H. |date=February 2000 |title=A Qualitative Piloted Evaluation of the Tupolev Tu-144 Supersonic Transport |publisher=[[Langley Research Center|NASA Langley Research Center]] |url=https://ntrs.nasa.gov/api/citations/20000025077/downloads/20000025077.pdf |archive-url=https://web.archive.org/web/20220313215417/https://ntrs.nasa.gov/api/citations/20000025077/downloads/20000025077.pdf |archive-date=13 March 2022 |url-status=live |access-date=31 July 2011}}</ref>

==Design==
Along with early [[Tupolev Tu-134|Tu-134s]], the Tu-144 was one of the last commercial aircraft with a [[braking parachute]]. The Tu-144 was not fitted with any reverse thrust capabilities, and so the parachute was used as the sole alternative.<ref name="bbc-20171018" /> A prototype without passenger seats was fitted with [[ejection seat]]s for pilots.<ref>{{cite magazine |title=Ramenskoye, Past and Present |magazine=Air Force Magazine |date=April 2008 |page=53 |url=https://books.google.com/books?id=uUHUMGqFoagC&pg=RA3-PA53 |access-date=25 February 2023 |archive-date=29 September 2023 |archive-url=https://web.archive.org/web/20230929162302/https://books.google.com/books?id=uUHUMGqFoagC&pg=RA3-PA53 |url-status=live }}</ref>

;Materials:
The aircraft was designed for a 30,000-hour service life over 15 years. Airframe heating and the high temperature properties of the primary structural materials, which were [[aluminium alloy]]s, set the maximum speed at Mach 2.2.<ref name="GordonKomissarovRigmant2015" />{{rp|page=49}} 15% by weight was [[titanium]] and 23% non-metallic materials. Titanium or stainless steel were used for the leading edges, elevons, rudder and the rear fuselage engine-exhaust [[heat shield]].<ref name="NASA Tu-144LL" />

===Engines===
[[File:Tupolev Tu-144 AN0521445.jpg|thumb|Afterburning nozzles on the Kuznetsov turbofan.]]
[[File:Tupolev Tu-144 at the MAKS-2013 (05).jpg|thumb|Plug nozzles on the non-afterburning Kolesov turbojet.]]

SSTs for M2.2 had been designed in the Soviet Union before Tupolev was tasked with developing one. Design studies for the [[Myasishchev]] SST had shown that a cruise [[Thrust specific fuel consumption|specific fuel consumption]] (SFC) of not more than 1.2&nbsp;kg/kgp hr would be required.<ref name="tupolev.ru"/> The only engine available in time with the required thrust and suitable for testing and perfecting the aircraft was the [[afterburning]] [[Kuznetsov NK-144]] [[turbofan]] with a cruise SFC of 1.58&nbsp;kg/kgp hr. Development of an alternative engine to meet the SFC requirement, a non-afterburning turbojet, the [[Kolesov RD-36-51]]A, began in 1964.<ref name="tupolev.ru" /> It took a long time for this engine to achieve acceptable SFC and reliability.<ref name="GordonKomissarovRigmant2015" />{{rp|page=42}} In the meantime the NK-144 high SFC gave a limited [[range (aeronautics)|range]] of about {{convert|2500|km|mi nmi|abbr=on|lk=out}}, far less than Concorde. A maximum speed of {{convert|2443|km/h|mph kn|abbr=on}} (Mach 2.35) was reached with afterburning.<ref name="GordonKomissarovRigmant2015" /> Afterburners were added to Concorde to meet its take-off thrust requirement<ref>Not Much of an Engineer, Sir Stanley Hooker, Airlife Publishing 2002, {{ISBN|978-1853102851}}, p. 153</ref> and were not necessary for supersonic cruise; the Tu-144 used maximum afterburner for take-off and minimum for cruise.<ref name="GordonKomissarovRigmant2015" />{{rp|page=110}}

The '''Tu-144S''', of which nine were produced, was fitted with the [[Kuznetsov NK-144]]A [[turbofan]] to address lack of take-off thrust and surge margin. SFC at M2.0 was 1.81&nbsp;kg/kgp hr. A further improvement, the NK-144V, achieved the required SFC, but too late to influence the decision to use the [[Kolesov RD-36-51]].<ref name="GordonKomissarovRigmant2015" />{{rp|page=135}}

The '''Tu-144D''', of which five were produced (plus one uncompleted), was powered by the [[Kolesov RD-36-51]] turbojet with an SFC of 1.22&nbsp;kg/kgp hr. The range with full payload increased to 5,330&nbsp;km compared to 6,470&nbsp;km for Concorde.<ref name="GordonKomissarovRigmant2015" />{{rp|page=248}} Plans for an aircraft with a range in excess of {{convert|7000|km|mi nmi|abbr=on}} range were never implemented.<ref name="tupolev.ru" />

The engine intakes had variable [[intake ramp]]s and bypass flaps with positions controlled automatically to suit the engine airflow.<ref name="tupolev.ru"/> They were very long to help prevent surging;<ref name="GordonKomissarovRigmant2015" />{{rp|page=131}} twice as long as those on Concorde. Jean Rech (Sud Aviation) states the need for excessive length was based on the misconception that length was required to attenuate [[intake]] distortion.<ref name="Owen2002">{{cite book |editor1-last=Owen |editor1-first=Kenneth |title=Concorde |date=2002 |publisher=Institute of Contemporary British History |location=London |isbn=0-9523210-7-6 |url=https://www.kcl.ac.uk/sspp/assets/icbh-witness/concorde.pdf |page=90 |archive-url=https://web.archive.org/web/20230531031823/https://www.kcl.ac.uk/sspp/assets/icbh-witness/concorde.pdf |archive-date=31 May 2023 |url-status=live }}</ref> The intakes were to be shortened by 10 feet on the projected '''Tu-144M'''.<ref name="GordonKomissarovRigmant2015" />{{rp|page=178}}

The [[Kolesov RD-36-51]] had an unusual translating plug nozzle as an alternative to a variable con-di nozzle, either of which give the variable area ratio required for the range of nozzle pressures which come from low inlet ram at low speeds to high at Mach 2. A plug nozzle was studied for [[Concorde]] but rejected as it was not certain that it could be cooled adequately during afterburner operation.<ref>https://arc.aiaa.org/doi/book/10.2514/4.868122, p.6-1</ref> The RD-36-51 had no afterburner.

===Airframe===
[[File:Tupolev Tu-144S, Aeroflot AN1180630.jpg|thumb| Tail surfaces or [[empennage]] showing deflected rudder and no horizontal tailplane.]]
[[File:Tupolev Tu-144 CCCP-77102 LEB 02.06.73 edited-3.jpg|thumb|right|The first production Tu-144S displaying at the 1973 [[Paris Air Show]] on the day before it crashed. The aircraft's planform and canards are clearly shown.]]
The aircraft was assembled from parts machined from large slabs, many over {{convert|19|m|ft|abbr=on}} long and {{convert|0.64|to|1.27|m|ft|abbr=on}} wide. While at the time, this approach was heralded as an advanced feature of the design, it turned out that finished parts contained defects which had not been detected in the [[raw material]]. Cracks formed at the defects at load levels below that which the part was expected to withstand. Once a crack started to grow, it spread quickly over many metres, with no crack-arresting design feature to stop it.<ref name="Fridlyander"/> In 1976, during [[Fatigue testing|repeat-load]] and [[Proof test|static testing]] at [[TsAGI]] (Russia's ''Central Aerohydrodynamic Institute''), a Tu-144S airframe cracked at 70% of the design flight load with cracks running many metres in both directions from their origin.<ref name="bliznyuk2000" /><ref name="Fridlyander"/>

Two Tu-144S airframes suffered structural failures during laboratory testing just prior to the Tu-144 entering passenger service.<ref name="Fridlyander">{{cite journal |last=Fridlyander |first=Iosif Naumovich |title=Печальная эпопея Ту-144 |trans-title=Sad Epic of the Tu-144 |journal=Messenger of Russian Academy of Sciences |year=2002 |volume=72 |issue=1 |pages=70–78 |url=http://vivovoco.rsl.ru/VV/JOURNAL/VRAN/02_01/FRID.HTM |archive-url=https://web.archive.org/web/20110928042757/http://vivovoco.rsl.ru/VV/JOURNAL/VRAN/02_01/FRID.HTM |archive-date=28 September 2011 |language=ru |url-status=dead }}</ref> The problem, discovered in 1976, may have been known prior to this testing; a large crack was discovered in the airframe of the prototype Tu-144 (aircraft 68001) during a stopover in Warsaw following its appearance at the 1971 Paris Air Show. Polish sources say the crack was discovered after the aircraft made an emergency landing due to the failure of both left-hand engines; however, an Aeroflot spokesperson denied the damage and disputed the circumstances of the landing.{{sfn|Moon|1989|p=141}}

Later the same year, a test airframe was subjected to a test simulating the temperatures and pressures occurring during a flight. High skin temperatures of {{convert|110|-|130|C|F|abbr=on|sigfig=2}} were caused by kinetic heating when the boundary layer air reached {{convert|150|-|180|C|F|abbr=on|sigfig=2}} during cruise. The Tu-144 was placed in an [[environmental chamber]] and heated to simulate the skin getting hot quickly, during acceleration to cruising speed, while the underlying structure took a while to reach its equilibrium temperature. This thermal effect caused internal stresses and the situation was reversed while slowing down and descending. The pressure in the cabin, which caused additional stresses, was changed at the same time as the skin heating to simulate climbing to cruise altitude and then descending. Repeatedly cycling the temperature and pressure, as happened with the aircraft in service, caused fatigue damage<ref>Tupolev Tu-144 The Soviet Supersonic Airliner,{{ISBN|978-0-7643-4894-5}}, pp.48,61</ref> and the airframe failed in a similar way to that of the TsAGI load testing.<ref name="bliznyuk2000" /><ref name="Fridlyander"/>

According to {{ill|Iosif Fridlyander|ru|Фридляндер, Иосиф Наумович}}, an aerospace aluminium and beryllium alloys expert,<ref name="AyzatullovaSudakov2020">{{cite journal |last1=Ayzatullova |first1=Alsu Sh. |last2=Sudakov |first2=Mikhail A. |title=История создания и эксплуатации сверхзвукового пассажирского самолёта Ту-144 (по мемуарным источникам) |trans-title=The History of the Creation and Operation of the TU-144 Supersonic Airliner (According to Memoir Sources) |journal=Vestnik of Kostroma State University |date=2020 |volume=26 |issue=3 |pages=87–92 |url=https://vestnik.ksu.edu.ru/2020-t-26-3/ayzatullova-as-sudakov-ma-vestnik-2020-3-ru.html |archive-url=https://web.archive.org/web/20230607000522/https://vestnik.ksu.edu.ru/2020-t-26-3/ayzatullova-as-sudakov-ma-vestnik-2020-3-ru.html |archive-date=7 June 2023 |url-status=live |doi=10.34216/1998-0817-2020-26-3-87-92 |doi-access=free |language=ru}}</ref>{{rp|page=88}} the Tu-144 design allowed a higher incidence of defects in the alloy structure, leading to the fatal in-air breakup of the aircraft in the [[1973 Paris Air Show Tu-144 crash]].<ref name="AyzatullovaSudakov2020" />{{rp|page=91}} This conclusion was supported by some of the designers involved in the aircraft's development. Vadim Razumikhin wrote that the [[Load factor (aeronautics)|load factor]] experienced by the plane at the moment of the break-up was less than the design limit. If the stress tests had been conducted earlier, the disaster may have been averted. Eventually, the airframe was strengthened and the control system was modified to prevent overstressing the aircraft.<ref name="bliznyuk2000" />{{rp|at=Ch. 3.14.}}

==Flight testing==
Tu-144 suffered from a rush in the design process to the detriment of thoroughness and quality.{{r|cnn-20190710|at="55 flights"|quote=But it didn't entirely convince the Soviets that the aircraft needed more testing. 'Political priorities to overcome the West, no matter what, obviously played a negative role, as they favored rushing over proper scheduling in a highly challenging and complicated field,' said Grinberg. When it finally started flying passengers in 1977, the Tu-144 turned out to be cramped, prone to breaking...}} According to Concorde technical flight manager Brian Calvert, "the rush to get [Tu-144] airborne exacted a heavy penalty later". Concorde's first flight was originally scheduled for February 1968, but was pushed back several times until March 1969 in order to iron out problems and test components more thoroughly.<ref name="calvert2002">{{cite book |last=Calvert |first=Brian |title=Flying Concorde: The Full Story |year=2002 |publisher=Airlife |location=London |isbn=1-84037-352-0 |url=https://archive.org/details/flyingconcordefu0000calv}}</ref>{{rp|page=127}} The rush is apparent even in outward timing: the 1963 government decree launching the Tu-144 programme defined that the Tu-144 should fly in 1968; it first flew on the last day of 1968 (31 December) to fulfill government goals set five years earlier.

==Production==
Sixteen [[Airworthiness|airworthy]] Tu-144 airplanes were built:
* the prototype Tu-144, registration number 68001
* a pre-production Tu-144, number 77101
* nine production Tu-144S, numbers 77102 to 77110
* five Tu-144D models, numbers 77111 to 77115.
Although its last commercial passenger flight was in 1978, production of the Tu-144 did not cease until 1983, when construction of the final airframe was stopped and left partially complete. The last production aircraft, Tu-144D number 77116, was not completed and was left derelict for many years on [[Pridacha Airport|Voronezh East airfield]]. There was at least one ground test airframe for static testing in parallel with the development of prototype 68001.

==Operational history==
===Entry into service===
The introduction of the Tu-144 into passenger service was timed to the 60th anniversary of the [[October Revolution|Communist revolution]], as was duly noted in Soviet officials' speeches delivered at the airport before the inaugural flight – whether the aircraft was actually ready for passenger service was deemed of secondary importance. Even the outward details of the inaugural Tu-144 flight betrayed the haste of its introduction into service: several ceiling panels were ajar, service trays stuck, window shades dropped without being pulled, reading lights did not work, not all toilets worked and a broken ramp delayed departure half an hour. On arrival to Alma-Ata, the Tu-144 was towed back and forth for 25 minutes to align it correctly with the exit ramp.{{sfn|Moon|1989|p=195}} Flight testing time logged on the prototype (68001) was 180 hours;<ref name="GordonRigmant2005" />{{rp|page=44}}<ref name="bliznyuk2000-ch13">{{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 |url=https://www.testpilot.ru/review/sst/3/13.htm |language=ru |chapter=13. Участие специалистов гражданской авиации в разработке и испытаниях самолета |date=10 March 2024 |publisher=Московский рабочий |trans-chapter=13. The Participation of Civil Aviation Experts in the Development and Testing of the Aircraft |isbn=978-5-239-02044-9 |archive-url=https://web.archive.org/web/20101003135825/http://www.testpilot.ru/review/sst/3/13.htm |archive-date=3 October 2010 |access-date=31 July 2011 |url-status=live}}</ref> flight testing time until the completion of state acceptance tests was 1509 hours,<ref name="bliznyuk2000-ch15">{{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 |url=https://www.testpilot.ru/review/sst/3/15.htm |language=ru |chapter=15. Совместные государственные испытания самолета Ту-144 |date=10 March 2024 |publisher=Московский рабочий |trans-chapter=15. Joint State Testing of the Tu-144 Aircraft |isbn=978-5-239-02044-9 |archive-url=https://web.archive.org/web/20090608192432/http://www.testpilot.ru/review/sst/3/15.htm |archive-date=8 June 2009 |access-date=31 July 2011 |url-status=live}}</ref> followed with 835 hours of flight time of service tests until the commencement of passenger service.<ref name="bliznyuk2000-ch16">{{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 |url=http://www.testpilot.ru/review/sst/3/16.htm |language=ru |chapter=16. Эксплуатационные испытания самолета Ту-144 |date=10 March 2024 |publisher=Московский рабочий |trans-chapter=16. Operational Testing of the Tu-144 Aircraft |isbn=978-5-239-02044-9 |archive-url=https://web.archive.org/web/20091221071050/http://testpilot.ru/review/sst/3/16.htm |archive-date=21 December 2009 |access-date=31 July 2011 |url-status=live}}</ref>

The Tu-144S went into service on 26 December 1975, flying mail and freight between Moscow and [[Almaty|Alma-Ata]] in preparation for passenger services, which commenced on 1 November 1977. The type certificate was issued by the [[USSR]] Gosaviaregister on 29 October 1977.<ref name="Maloy2012">{{cite book |last=Малой |first=Б. С. |date=2012 |editor-last=Пухов |editor-first=А. А. |title=Практическая сертификация авиационной техники: учебно-методическое пособие для студентов вузов, аспирантов, молодых специалистов |trans-title=Practical Certification of Aviation Equipment: Educational and Methodological Manual for University Students, Postgraduates, Young Specialists |url=https://search.rsl.ru/ru/record/01006537048 |language=ru |location=Moscow |publisher=Ваш полиграфический партнер |isbn=978-5-4465-0032-1 |access-date=8 February 2018 |archive-date=8 February 2018 |archive-url=https://web.archive.org/web/20180208182912/https://search.rsl.ru/ru/record/01006537048 |url-status=live }}</ref>

The passenger service ran a semi-scheduled service until the first Tu-144D experienced an in-flight failure during a pre-delivery test flight, crash-landing on 23 May 1978 with two crew fatalities.<ref name="TU144 Accidents">{{cite web |url=http://www.tu144sst.com/accidents/accidentsindex.html |title=Accidents/Incidents |archive-url=https://web.archive.org/web/20160429074830/http://www.tu144sst.com/accidents/accidentsindex.html |archive-date=29 April 2016 |url-status=live |website=TU144sst.com |access-date=31 July 2011}}</ref> The Tu-144's 55th and last scheduled passenger flight occurred on 1 June 1978.

An [[Aeroflot]] freight-only service recommenced using the new production variant ''Tu-144D'' ("D" for ''Dal'nyaya'' – "long range"){{citation needed|date=January 2024}} aircraft on 23 June 1979, including longer routes from Moscow to [[Khabarovsk Novy Airport|Khabarovsk]] made possible by the more efficient Kolesov RD-36-51 turbojet engines, which also increased the maximum cruising speed to Mach 2.15.<ref name="NASA Tu-144LL">{{cite web |url=http://www.nasa.gov/centers/dryden/news/FactSheets/FS-062-DFRC.html |title=The Tu-144LL: A Supersonic Flying Laboratory |editor-last=Curry |editor-first=Marty |date=15 December 2009 |archive-url=https://web.archive.org/web/20111026172537/http://www.nasa.gov/centers/dryden/news/FactSheets/FS-062-DFRC.html |archive-date=26 October 2011 |url-status=dead |publisher=[[NASA]] |website=Dryden Flight Research Center: Fact Sheets |access-date=31 July 2011}}</ref>

There were only 103 scheduled flights before the Tu-144 was removed from commercial service.

===Early flights===
During 102 flights and 181 hours of freight and passenger flight time, the Tu-144S suffered more than 226 failures; 80 of them occurred in flight and 80 of them were severe enough to affect the flight schedule. The most frequent sources of trouble were the flight instruments, navigation gear, radios, and [[autopilot]].{{sfn|Moon|1989|p=197}}

After the inaugural flight, two subsequent flights during the next two weeks were cancelled and the third flight rescheduled. The official reason given by Aeroflot for cancellation was bad weather at Alma-Ata; however when the journalist called the Aeroflot office in Alma-Ata about local weather, the office said that the weather there was perfect and one aircraft had already arrived that morning.<ref name="UPI-19771123">{{cite news |url=https://www.newspapers.com/article/the-star-press-soviets-scrub-sst-flight/135115998/ |title=Soviets Scrub SST Flight |agency=[[United Press International|UPI]] |date=23 November 1977 |newspaper=[[The Star Press|Muncie Star]] |page=5 |volume=101 |issue=238 |archive-url=https://web.archive.org/web/20231113084056/https://www.newspapers.com/article/the-star-press-soviets-scrub-sst-flight/135115998/ |archive-date=13 November 2023 |url-status=live |access-date=13 November 2023}}</ref> Subsequent and significant documented Tu-144 failures included insufficient cabin pressurisation in flight on 27 December 1977, a landing gear switch fault on 29 January 1978 that indicated that the gear was lowered when it was in fact retracted, and engine-exhaust duct overheating causing the flight to be aborted and returned to the takeoff airport on 14 March 1978. Additionally, a metal fatigue problem was discovered in the tip of the aircraft's vertical stabilizer; this was mitigated by adding a titanium doubler plate.{{sfn|Moon|1989|pp=197–199}}

Aleksey Tupolev, Tu-144 chief designer, and two USSR vice-ministers (of aviation industry and of civil aviation) had to be personally present at Domodedovo airport before each scheduled Tu-144 departure to review the condition of the aircraft and make a joint decision on whether it could be released into flight.<ref name= "Melik-Karamov 2000">{{cite web |url=http://www.ropnet.ru/ogonyok/win/200003/03-26-31.html |archive-url=https://web.archive.org/web/20001115093200/http://www.ropnet.ru/ogonyok/win/200003/03-26-31.html |title=Жизнь и смерть самолета "ТУ-144" |last=Melik-Karamov |first=Vitaly |archive-date=15 November 2000 |access-date=9 April 2021 |language=ru |trans-title=Life and Death of the aircraft "TU-144" |url-status=dead }}</ref> Subsequently, flight cancellations became less common, as several Tu-144s were docked at Moscow's [[Domodedovo International Airport]].{{Citation needed|date= April 2011}}

====Incident on 25 January 1978====
Tu-144 pilot Aleksandr Larin remembers a troublesome flight around 25 January 1978. The flight with passengers suffered the failure of 22 to 24 onboard systems. Seven to eight systems failed before takeoff, but given the large number of foreign TV and radio journalists and also other foreign notables aboard the flight, it was decided to proceed with the flight to avoid the embarrassment of cancellation. After takeoff, failures continued to multiply. While the aircraft was supersonic en route to the destination airport, Tupolev bureau's crisis centre predicted that the front and left landing gear would not extend and that the aircraft would have to land on the right gear alone, at a landing speed of over {{convert|300|km/h|mph kn|abbr=on}}. Due to expected political fallout, [[Soviet]] leader [[Leonid Brezhnev]] was personally notified of what was going on in the air. With the accumulated failures, an alarm siren went off immediately after takeoff, with sound and volume similar to that of a civil defence warning. The crew could not figure a way to switch it off so the siren stayed on throughout the remaining 75 minutes of the flight. Eventually, the captain ordered the navigator to borrow a pillow from the passengers and stuff it inside the siren's horn. After all the suspense, all landing gear extended and the aircraft landed.<ref name= "Melik-Karamov 2000"/>

A subsequent flight of Tu-144 on around 30 May 1978, not long before the type was withdrawn from passenger service, involved valve failure on one of the fuel tanks.<ref name= "Melik-Karamov 2000"/>

===Cabin noise===
A problem for passengers was the very high noise level inside the cabin, measuring at least 90–95&nbsp;dB on average.<!-- decibel level obtained from NASA engineer in person --> The noise came from the engines; unlike Concorde, it could only sustain supersonic speeds using afterburners continuously. In addition, the active heat insulation system used for the air conditioning, which used the flow of spent cabin air, was described as excessively noisy. Passengers seated next to each other could have a conversation only with difficulty, and those seated two seats apart could not hear each other even when screaming and had to pass hand-written notes instead. Noise in the rear of the cabin was described as unbearable.{{sfn|Moon|1989|p=195}}{{#tag:ref|See contemporary passenger reports about the noise problem<ref name="Soviet Union 1977">{{cite magazine |url=https://content.time.com/time/subscriber/article/0,33009,912014,00.html |title=Soviet Union: Christening the Concordski |magazine=[[Time (magazine)|Time]] |date=14 November 1977 |archive-url=https://web.archive.org/web/20211110085315/http://content.time.com/time/subscriber/article/0,33009,912014,00.html |archive-date=10 November 2021 |url-status=live}}</ref><ref>{{cite news|title=Soviet supersonic jet goes into service |newspaper=The Times |location=London|date=2 November 1977}}</ref>{{page needed|date=December 2021}}<ref name="wapo-19771102">{{cite news |title=Soviets Launch SST Flights With Cognac, Caviar |newspaper=[[The Washington Post]] |date=2 November 1977}}</ref><ref>{{citation |url=https://www.nytimes.com/1977/11/02/archives/soviet-sst-takes-off-in-moscow-and-you-almost-hear-it-in-queens.html |title=Soviet SST Takes Off in Moscow – And You Almost Hear it in Queens |archive-url=https://web.archive.org/web/20211110085319/https://www.nytimes.com/1977/11/02/archives/soviet-sst-takes-off-in-moscow-and-you-almost-hear-it-in-queens.html |archive-date=10 November 2021 |newspaper=[[New York Times]] |date= 2 November 1977}}</ref><ref name="TU144 Cabin Noise">{{cite web |url=http://www.oboguev.net/misc/tu144-cabin-noise.htm |title=Cabin noise |archive-url=https://web.archive.org/web/20110723231451/http://www.oboguev.net/misc/tu144-cabin-noise.htm |archive-date=23 July 2011 |website=oboguev.net |access-date=25 January 2011 |url-status=live}}</ref>|group=N}}

===Later use===
[[File:Russian Tu-144LL SST Flying Laboratory Takeoff at Zhukovsky Air Development Center.jpg|thumb|The Tu-144LL used by [[NASA]] to carry out research for the [[High Speed Civil Transport]] in 1997.]]
[[File:Tu-144LL in flight.jpg|thumb|Tu-144LL in flight in 1998.]]
[[File:МАКС-2007-ЗВГ-002.jpg|thumb|Tu-144 with distinctive [[Droop nose (aeronautics)|droop nose]] on display at the [[MAKS Airshow]] in 2007.]]
The Tu-144 programme was cancelled by a Soviet government decree on 1 July 1983 that also provided for future use of the remaining Tu-144 aircraft as airborne laboratories. In 1985, Tu-144D were used to train pilots for the Soviet [[Buran (spacecraft)|Buran]] space shuttle. In 1986–1988 Tu-144D No. 77114, built in 1981, was used for medical and biological research of high-altitude atmosphere radiological conditions. Further research was planned but not completed, due to lack of funding.<ref name="bliznyuk2000" />

===Use by NASA===
In the early 1990s, Judith de Paul, and her company IBP Aerospace brokered an agreement with Tupolev, [[NASA]], [[Rockwell International|Rockwell]] and later [[Boeing]]. They offered a Tu-144 as a testbed for NASA's High Speed Commercial Research programme, which was intended to design a second-generation supersonic jetliner called the [[High Speed Civil Transport]].<ref>{{cite journal |last1=Huntington |first1=Tom |title=Encore for an SST |journal=Air & Space/Smithsonian |date=October–November 1995 |url=http://www.aviation.ru/Tu/144/story1/ASM_T144_ON95.html |archive-url=https://web.archive.org/web/20020911214606/http://www.aviation.ru/Tu/144/story1/ASM_T144_ON95.html |archive-date=11 September 2002 |access-date=29 May 2023 |url-status=live }}</ref> In 1995, Tu-144D No. 77114 (with only 82.5 hours of flight time) was taken out of storage and after extensive modification at a cost of US$350{{nbsp}}million, designated the ''Tu-144LL'' (where LL is a Russian abbreviation for Flying Laboratory, {{langx|ru|Летающая Лаборатория}}, ''Letayushchaya Laboratoriya''). The aircraft made 27 flights in Russia during 1996 and 1997.<ref name="NASA Tu-144LL" /> Though regarded as a technical success, the project was cancelled for lack of funding in 1999.

This aircraft was reportedly sold in 2001 online, but the aircraft sale did not proceed. Tejavia Systems, the company handling the transaction, reported that the deal was not signed as the replacement [[Kuznetsov NK-321]] engines also used in a [[Tupolev Tu-160]] bomber were military hardware and the Russian government would not allow them to be exported.<ref>{{cite web |title=ANN Exclusive: What Happened to the Tu-144 Sale? |url=http://www.aero-news.net/index.cfm?do=main.textpost&id=5d307b97-9ec1-4c9b-b3e7-796230514a8b |website=Aero-News Network |archive-url=https://web.archive.org/web/20230617230108/http://www.aero-news.net/index.cfm?do=main.textpost&id=5d307b97-9ec1-4c9b-b3e7-796230514a8b |archive-date=17 June 2023 |date=21 March 2022 |url-status=live |access-date=17 June 2023 }}</ref>

In 2003, after the retirement of Concorde, there was renewed interest from several wealthy individuals who wanted to use the Tu-144LL for a transatlantic record attempt, despite the high cost of a flight readiness overhaul even if military authorities would authorize the use of NK-321 engines outside Russian Federation airspace.{{citation needed|date=October 2015}}

==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}}

===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}}

==Cessation of Tu-144D production==
The decision to cease Tu-144D production was issued on 7 January 1982, followed by a USSR government decree dated 1 July 1983 to cease the whole Tu-144 programme and to use produced Tu-144 aircraft as flying laboratories.<ref name="bliznyuk2000" />

===Soviet leadership failure===
Howard Moon, who authored "Soviet SST" in 1989, attributed the downfall of the ostensibly promising Tu-144 programme to the Soviet leadership's decision to leverage it as a political weapon against the West. He regarded the programme as both an "astounding achievement" and a "magnificent failure".<ref>{{cite web |title=Soviet Sst, the by Howard Moon |url=https://www.publishersweekly.com/9780517566015 |website=Publishers Weekly |date=July 1989 |access-date=12 June 2023 |archive-date=12 June 2023 |archive-url=https://web.archive.org/web/20230612171631/https://www.publishersweekly.com/9780517566015 |url-status=live }}</ref>

The rushed introduction to service of poorly tested aircraft happened previously with another Tupolev project that had high political visibility and prestige: the [[Tupolev Tu-104|Tu-104]] passenger jet-liner was the first successful Soviet passenger jet in service. In a decision-making similar to the Tu-144-story, the Soviet government introduced the Tu-104 into passenger service before satisfactory stability and controllability had been achieved. During high-altitude and high-speed flight the aircraft was prone to longitudinal instability, and also at high altitudes, it had a narrow range of [[angle of attack]] separating the aircraft from [[Stall (flight)|stalls]] known as [[coffin corner (aerodynamics)|coffin corner]]. These problems created the preconditions for spin dives, that happened twice before the Tu-104 was eventually properly tested and the problem was resolved.<ref name="Shcherbakov">{{cite web |last=Shcherbakov |first=Aleksandr |title=Реквием по Ту-144 |trans-title=Requiem for the Tu-144 |url=http://nvo.ng.ru/history/2008-06-06/11_tu144.html |website=Независимое Военное Обозрение (Independent Military Review) |date=6 June 2008 |language=ru |archive-url=https://web.archive.org/web/20100728225824/http://nvo.ng.ru/history/2008-06-06/11_tu144.html |archive-date=28 July 2010 |url-status=dead }}</ref>{{Original research inline|date=June 2023|reason=The source doesn't say that this was a reason for the project cancellation.}}

===Personal factors===
{{ill|Leonid Selyakov|ru|Селяков, Леонид Леонидович}}, a notable Soviet aircraft designer,<ref name="AyzatullovaSudakov2020" />{{rp|page=88}} considered the primary reason for ending the Soviet Supersonic Transport project to be the personal factor—the role of the Chief Designer, who failed to show due courage and defend his Bureau's brainchild following the [[1978 Yegoryevsk Tu-144 crash|tragic event near Yegoryevsk]]. "Cowardice and progress are incompatible," Selyakov sternly summarized.<ref name="AyzatullovaSudakov2020" />{{rp|page=91}}

G.A. Cheryomukhin identified several major "blows" to the Tu-144 project. The first three were the death of [[Andrei Tupolev]] in 1972, the [[1973 Paris Air Show Tu-144 crash|disaster at the Air Show in 1973]], and the death of the active and authoritative Minister of the USSR's Aviation Industry {{ill|Pyotr Vasilievich Dementyev|ru|Дементьев, Пётр Васильевич}} (1907–1977). Dementyev had been at the helm of the domestic aviation industry for many years and was one of the champions of the SST program. The fourth blow came with [[Aleksey Tupolev]]'s direction on 30 May 1978, to cancel the SST flight and temporarily halt aircraft operations. Cheryomukhin bitterly noted, "...our own leader – A.A. Tupolev – personally stopped the operation of the Tu-144, depriving the world of a source of evidence of the rationality of supersonic flight over land..."<ref name="AyzatullovaSudakov2020" />{{rp|page=91}}

==After project cancellation==
After ceasing the Tu-144 programme, Tu-144D No. 77114 (aircraft 101 or 08-2) carried out test flights between the 13–20 July 1983 to establish 13 world records registered with the [[Fédération Aéronautique Internationale|Fédération Aéronautique Internationale (FAI)]].<ref name="fai-records">{{cite web |title=Tu-144 records |url=http://records.fai.org:81/astronautics/aircraft.asp?id=1098 |publisher=[[Fédération Aéronautique Internationale|FAI]] |archive-url=https://web.archive.org/web/20100607075233/http://records.fai.org:81/astronautics/aircraft.asp?id=1098 |archive-date=7 June 2010 |access-date=31 July 2011 |url-status=dead}}</ref>
<ref>{{cite web |title=Records - Sub-class C-1 |url=http://www.samolet.co.uk/c1_g3.html |publisher=Samolet.co.uk |archive-url=https://web.archive.org/web/20071109162410/http://www.samolet.co.uk/c1_g3.html |archive-date=9 November 2007 |access-date=31 July 2011 |url-status=dead}}</ref> These records established an altitude of {{convert|18200|m|ft}} with a range of loads up to 30 tonnes, and a sustained speed of {{convert|2032|km/h|mph kn|abbr=on}} over a closed circuit of up to {{convert|2000|km|mi nmi|abbr=on}} with similar loads.{{citation needed|date=December 2021}}

To put the numbers in perspective, Concorde's service ceiling under a typical [[Transatlantic flight]] payload of 10 tonnes was {{convert|18290|m|ft|abbr=on|sigfig=2}},{{#tag:ref|The actual altitude of the regular Concorde flight depends on the state of [[troposphere]], which in turn depends on latitude of the flight. Concorde flights across the tropical region is 60,000&nbsp;ft, with flights across North Atlantic at only 56–58,000&nbsp;ft to ensure the most economic service.<ref name="calvert2002" />|group=N}} and this is higher than the record set by the Tu-144D. According to unverified sources, during a 26 March 1974 test flight a Concorde reached its maximum speed ever of {{convert|2370|km/h|mph kn|abbr=on}} (Mach 2.23) at an altitude of {{convert|19415|m|ft|abbr=on|sigfig=3}}, and during subsequent test flights reached maximum altitude of {{convert|20700|m|ft|abbr=on|sigfig=3}}.

Concorde was originally designed for cruising speeds up to Mach 2.2,<ref>'Design for Mach 2.2', Flight International,23 April 1964, p.649</ref> but its regular service speed was limited to Mach 2.02 to extend airframe life.<ref>Brian Trubshaw Test Pilot,{{ISBN|0 7509 1838 1}}, p.99</ref> One of Tupolev's web site pages states that "TU-144 and TU-160 aircraft operation has demonstrated expediency of limitation of cruise supersonic speed of M=2.0 to provide structure service life and to limit cruising altitude".<ref name="Tu-444">{{cite web |title=Tu-444 |url=http://www.tupolev.ru/English/Show.asp?SectionID=199 |website=tupolev.ru |archive-url=https://archive.today/20120918125526/http://www.tupolev.ru/English/Show.asp?SectionID=199 |archive-date=18 September 2012 |access-date=31 July 2011 |url-status=dead}}</ref>

==Variants==
* '''Tu-144''' – ('''''izdeliye 044''''' – article 044) The sole prototype Tu-144 aircraft<ref name="GordonRigmant2005" />{{page needed|date=December 2021}}
* '''Tu-144S''' – ('''''izdeliye 004''''' – article 004) Six redesigned production aircraft powered by Kuznetsov NK-144A engines in widely spaced [[nacelle]]s, and redesigned undercarriage<ref name="GordonRigmant2005" />{{page needed|date=December 2021}}
* '''Tu-144D''' – ('''''izdeliye 004D''''' – article 004D)(D-''Dahl'neye'' – long-range) Production Tu-144 aircraft powered by Koliesov RD36-51 non-afterburning engines. One aircraft converted from Tu-144 СССР-77105(c/n10031) and five production aircraft (СССР-77111 [c/n10062] to СССР-77115 [c/n 10091]) plus one (СССР-77116) uncompleted<ref name="GordonRigmant2005" />{{page needed|date=December 2021}}
* '''Tu-144DA'''<span class="anchor" id="Tu-144DA"></span> – A project study, assigned the number Tu-144DA, increased the wing area and the take-off weight, and replaced the engines with the [[RD-36-61]] which had 5% more thrust. The Tu-144DA increased fuel capacity from 98,000&nbsp;kg to 125,000&nbsp;kg with a higher maximum certified take-off weight (MCTOW) of 235,000&nbsp;kg. and range up to {{convert|7500|km|mi|abbr=on}}.<ref name="tupolev.ru"/>
* '''Tu-144LL''' – One Tu-144D aircraft (СССР-77114 [c/n10082]) converted to a flying laboratory with four [[Kuznetsov NK-321]] afterburning turbofan engines and re-registered RA-77114. The first flight took place on 29 November 1996 with the 27th and last flight on 14 April 1999.{{Citation needed|date=November 2023|reason=Verification needed as this information appears to have been added by a first-hand source, according to the edit summary: https://en.wikipedia.org/w/index.php?diff=853501089}}

===Proposed military versions===
{{See also|Tu-160}}
Early configurations of the Tu-144 were based on the unbuilt [[Tupolev Tu-135]] bomber, retaining the latter aircraft's [[Canard (aeronautics)|canard]] layout, wings and nacelles. Deriving from the Tu-135 bomber, Tupolev's early design for supersonic passenger airplane was code-named Tu-135P before acquiring the Tu-144 project code.<ref name="GordonRigmant2005" />{{rp|pages=8–9}}<ref name="Tu-135 Testpilot">{{cite web |title="135" (Ту-135) - сверхзвуковой стратегический бомбардировщик |trans-title=Tu-135 - Supersonic Strategic Bomber |url=https://www.testpilot.ru/russia/tupolev/135/ |website=testpilot.ru |language=ru |archive-url=https://web.archive.org/web/20230929162307/http://www.testpilot.ru/russia/tupolev/135/ |archive-date=29 September 2023 |access-date=31 July 2011 |url-status=live}}</ref><ref name="Tu-135P Testpilot">{{cite web |title="135П" - сверхзвуковой пассажирский самолет |trans-title=Tu-135P - Supersonic Passenger Aircraft |url=https://www.testpilot.ru/russia/tupolev/135/p/ |website=testpilot.ru |language=ru |archive-url=https://web.archive.org/web/20230929162312/http://www.testpilot.ru/russia/tupolev/135/p/ |archive-date=29 September 2023 |access-date=31 July 2011 |url-status=live}}</ref>

Over the course of the Tu-144 project, the Tupolev bureau created designs of a number of military versions of Tu-144 but none were ever built. In the early 1970s, Tupolev was developing the Tu-144R intended to carry and air-launch up to three solid-fueled [[ICBMs]]. The launch was to be performed from within Soviet air space, with the aircraft accelerating to its maximum speed before releasing the missiles. The original design was based on the Tu-144S, but later changed to be derived from the Tu-144D. Another version of the design was to carry air-launched long-range [[cruise missiles]] similar to the [[Kh-55]]. The study of this version envisioned the use of [[liquid hydrogen]] for the afterburners.

In the late 1970s, Tupolev contemplated the development of a long-range heavy interceptor (DP-2) based on the Tu-144D also able to escort bombers on long-range missions. Later this project evolved into an aircraft for [[electronic countermeasures]] (ECM) to suppress enemy radars and facilitate bomber's penetration through enemy air defenses (Tu-144PP). In the early 1980s this functionality was supplanted with theatre and strategic reconnaissance (Tu-144PR).

The dimmer civil prospects for Tu-144 were becoming apparent the more Tupolev tried to "sell" the aircraft to the military. One of the last attempts to sell a military version of the Tu-144 was the Tu-144MR, a project for a long-range reconnaissance aircraft for the Soviet Navy intended to provide targeting information to the Navy's ships and submarines on sea and oceanic theaters of operations. Another proposed navy version was to have a strike capability (two Kh-45 air-to-surface cruise missiles), along with a reconnaissance function.<ref name="GordonRigmant2005" />{{rp|pages=107–110}} The Tu-144MR was also to have served as a carrier aircraft for the [[Tupolev Voron]] [[reconnaissance]] [[Unmanned aerial vehicle|drone]], designed to compete with the [[Lockheed D-21]] and influenced by it, but the project never materialised.<ref name="GordonRigmant2006">{{cite book |last1=Gordon |first1=Yefim |author-link1=Yefim Gordon |last2=Rigmant |first2=Vladimir |title=OKB Tupolev: A History of the Design Bureau and its Aircraft |year=2006 |publisher=Midland Publishing |isbn=1-85780-214-4 |url=https://archive.org/details/okb-tupolev.-a-history-of-the-design-bureau-and-its-aircraft}}</ref>

The military was unreceptive to Tupolev's approaches. [[Vasily Reshetnikov]], the commander of Soviet [[Soviet Long Range Aviation|Long-Range Aviation]] and subsequently, a vice-commander of the Soviet Air Force, remembers how, in 1972, he was dismayed by Tupolev's attempts to offer for military use the aircraft that "fell short of its performance target, was beset by reliability problems, fuel-thirsty and difficult to operate".<ref name="reshetnikov04">{{cite web |last=Reshetnikov |first=V. |title=Что было – то было |trans-title=What was – was |year=2004 |url=http://militera.lib.ru/memo/russian/reshetnikov_vv/04.html |publisher=Militera.lib.ru |archive-url=https://web.archive.org/web/20090925161314/http://militera.lib.ru/memo/russian/reshetnikov_vv/04.html |archive-date=25 September 2009 |access-date=31 July 2011 |language=ru |url-status=dead}}</ref>

Reshetnikov goes on to remember:
<blockquote>The development and construction of the supersonic airliner, the future Tu-144, was included in the five-year plan and was under the auspices of the influential [[Dmitry Ustinov|D.F. Ustinov]] (then Soviet minister of defence and confidant of Brezhnev, who represented interests of defence industries lobby in opposition to the military) who regarded this mission as a personal responsibility – not so much to his country and people as to "dear Leonid Il'ych" (Brezhnev) whom he literally worshipped, sometimes to the point of shamelessness... Yet the supersonic passenger jet was apparently not making headway and, to the dismay of its curator, it looked as though Brezhnev might be disappointed. It was then that Dmitry Fedorovich (Ustinov) jumped at someone's idea to foist Aeroflot's "bride in search of a wedding" on the military. After it had been rejected in bomber guise, Ustinov used the Military Industrial Commission (one of the most influential Soviet government bodies) to promote the aircraft to the Strategic Aviation as a reconnaissance or ECM platform, or both. It was clear to me that these aircraft could not possibly work in concert with any bomber or missile carrier formation; likewise I could not imagine them operating solo as "Flying Dutchmen" in a war scenario, therefore I resolutely turned down the offer.<ref name="reshetnikov04" /></blockquote>

Naval Aviation Commander Aleksandr Alekseyevich Mironenko, followed suit:

<blockquote>Ustinov could not be put off that easily. He managed to persuade the Navy C-in-C (admiral) [[Sergey Gorshkov|S.G. Gorshkov]] who agreed to accept the Tu-144 for Naval Aviation service as a long-range reconnaissance aircraft without consulting anyone on the matter. Mironenko rebelled against this decision, but the commander-in-chief would not hear of heed – the issue is decided, period. On learning of this I was extremely alarmed: if Mironenko had been pressured into taking the Tu-144, this meant I was going to be next. I made a phone call to Aleksandr Alekseyevich, urging him to take radical measures; I needn't have called because even without my urging Mironenko was giving his C-in-C a hard time. Finally Ustinov got wind of the mutiny and summoned Mironenko to his office. They had a long and heated discussion but eventually Mironenko succeeded in proving that Ustinov's ideas were unfounded. That was the last time we heard of Tu-144.<ref name="reshetnikov04" /></blockquote>

==Operators==
; {{USSR}}
* [[Ministry of Aviation Industry (Soviet Union)|Ministry of Aviation Industry]]<ref name="KandalovDuffy1996">{{cite book |last1=Kandalov |first1=Andrei |last2=Duffy |first2=Paul |title=Tupolev: The Man and His Aircraft |year=1996 |publisher=Society of Automotive Engineers |location=Warrendale, Pennsylvania |isbn=1-56091-899-3 |lccn=96-70235 |url=https://archive.org/details/sae-international-tupolev-the-man-and-his-aircraft}}</ref>{{rp|page=156}}
* [[Aeroflot Soviet Airlines]]
; {{USA}}
* [[NASA]]

==Aircraft on display==
[[File:Tupolev Tu-144 @ Central Air Force Museum.jpg|thumb|left|Tu-144S#77106 preserved at [[Monino]] museum]]
[[File:Maintenance of memorial Tu-144 reg. No. 77114 in Zhukovsky, Russia.jpg|thumb|left|Seasonal maintenance of memorial Tu-144 reg. No. 77114 in Zhukovsky, Russia]]
[[File:Technik Museum Sinsheim, Tu-144.jpg|thumb|Tu-144D#77112 on display at [[Technik Museum Sinsheim]], Germany]]
[[File:TU 144 Sinsheim side.JPG|thumb|220px|right|Tu-144 at Sinsheim Museum.]]
[[File:Tupolev Tu-144 - complete rear view.jpg|thumb|TU-144 at Sinsheim Museum.]]
While several Tu-144s were donated to museums in Moscow [[Monino]], [[Samara, Russia|Samara]] and [[Ulyanovsk Aircraft Museum|Ulyanovsk]], at least two Tu-144D remained in open storage in Moscow Zhukovsky.<!---Past tense is correct, as no current information exists.--->

As of June 2010, two aircraft (tail numbers СССР-77114 and СССР-77115) are located outdoors at [[Gromov Flight Research Institute]], Zhukovsky (at coordinates {{Coord|55.569786|38.155652|aircraft_type:landmark}} and {{Coord|55.571776|38.152304|aircraft_type:landmark}}). Previously, they were displayed at [[MAKS Airshow]]s. Tail number 77115 was bought in 2005 by the Heros Club of Zhukovsky and still on display at MAKS as of 2019.<ref>{{Cite web|url=http://www.testpilots.ru/Tu-144/|title=Ту-144 — Герои неба|website=www.testpilots.ru|access-date=22 December 2019|archive-date=22 December 2019|archive-url=https://web.archive.org/web/20191222222039/http://www.testpilots.ru/Tu-144/|url-status=live}}</ref> In 2019, tail number 77114 was repainted in Aeroflot livery and put on display in front of the Gromov Flight Research institute main gate.<ref>{{cite web |title=Zhukovsky pays tribute to the venerable Tu-144 supersonic airliner |url=https://www.rusaviainsider.com/zhukovsky-pays-tribute-venerable-tu-144-supersonic-airliner/ |website=Russian Aviation Insider |access-date=17 June 2023 |date=26 August 2019 |archive-date=17 June 2023 |archive-url=https://web.archive.org/web/20230617231629/https://www.rusaviainsider.com/zhukovsky-pays-tribute-venerable-tu-144-supersonic-airliner/ |url-status=dead }}</ref>

A Tu-144S, registration СССР-77106, is on display at [[Central Air Force Museum]] of Russia in Monino. Its maiden flight was on 4 March 1975, the final one on 29 February 1980. The aircraft was used to assess the effectiveness of the air-conditioning systems and to solve some problems on the fuel system. It can be considered the first production aircraft, being the first to be equipped for commercial use and delivered to Aeroflot. The first operational flight was on 26 December 1975 between Moscow and Alma-Ata carrying cargo and mail.<ref>{{cite web|url=http://www.tu144sst.com/fleet/04-1.html|title=TU-144 SST : AEROFLOT FLEET : 04-1|website=www.tu144sst.com|access-date=1 July 2012|archive-date=30 June 2012|archive-url=https://web.archive.org/web/20120630161641/http://www.tu144sst.com/fleet/04-1.html|url-status=live}}</ref>

Another Tu-144, tail number СССР-77107, is on open display in Kazan and located at {{Coord|55.821714|49.135064|aircraft_type:landmark}}. The aircraft was constructed in 1975 and was a production model intended for passenger use. However, it was only used during test flights. On 29 March 1976 it made its last flight to Kazan. This aircraft was put on sale on [[eBay]] in 2017.<ref name="Russian TU-144 SST Airliner">{{cite web|title=Russian TU-144 SST Airliner|url=http://www.ebay.com/itm/Russian-TU-144-SST-Airliner-/182489803931?hash=item2a7d3d6c9b:g:U-0AAOSw241Yk5u2&vxp=mtr|archive-url=https://web.archive.org/web/20170323175316/http://www.ebay.com/itm/Russian-TU-144-SST-Airliner-/182489803931?hash=item2a7d3d6c9b%3Ag%3AU-0AAOSw241Yk5u2&vxp=mtr|archive-date=23 March 2017|url-status=dead}}</ref><ref>[http://www.znachok.in.ua/modules/TDMPicture/viewcat.php?ct=11&view_mode=block]{{dead link|date=February 2018|bot=InternetArchiveBot|fix-attempted=yes}} ''Znachok Soviet COllectibles''</ref>

TU-144S, tail number СССР-77108, is on display in the museum of Samara State Aerospace University ({{Coord|53.240367|50.364092|aircraft_type:landmark}}). It made its maiden flight on 12 December 1975, and its final flight on 27 August 1987. Development works on navigation system were made in this aircraft as well as [[Flight director (aeronautics)|flight-director]] approach.<ref>{{cite web|url=http://www.tu144sst.com/fleet/04-2.html|title=TU-144 SST : AEROFLOT FLEET : 04-2|website=www.tu144sst.com|access-date=1 July 2012|archive-date=30 June 2012|archive-url=https://web.archive.org/web/20120630161646/http://www.tu144sst.com/fleet/04-2.html|url-status=live}}</ref>

TU-144S, tail number СССР-77110, is on display at the [[Ulyanovsk Aircraft Museum]] in [[Ulyanovsk]]. Maiden flight occurred on 14 February 1977, the final Flight on 1 June 1984. This aircraft was the second of the two aircraft used for regular passengers' flights on Moscow – Alma-Ata route. In 1977 it flew to Paris to take part in the XXXII Paris Air Show at Le Bourget Airport. This was the last appearance of a Tu-144 in West Europe.
СССР-77110 was the last aircraft produced of the model Tu-144S, powered with Kuznetsov NK-144A engines.
In the first half of 2008 the cabin was open for visits and between August and September was restored and painted in the original Aeroflot livery.<ref>{{cite web|url=http://www.tu144sst.com/fleet/06-1.html|title=TU-144 SST : AEROFLOT FLEET : 06-1|website=www.tu144sst.com|access-date=1 July 2012|archive-date=30 June 2012|archive-url=https://web.archive.org/web/20120630162710/http://www.tu144sst.com/fleet/06-1.html|url-status=live}}</ref>

The only Tu-144 on display outside the former Soviet Union, tail number СССР-77112, was acquired by the [[Technik Museum Sinsheim|Auto & Technikmuseum Sinsheim]] in Germany, where it was shipped – not flown – in 2001 and where it now stands, in its original Aeroflot livery, on display next to an [[Air France]] Concorde.<ref>{{cite web |title=Tupolev Tu-144 |url=https://sinsheim.technik-museum.de/de/tupolev-tu-144 |language=de |publisher=[[Technik Museum Sinsheim]] |archive-url=https://web.archive.org/web/20230703091327/https://sinsheim.technik-museum.de/de/tupolev-tu-144 |archive-date=3 July 2023 |access-date=13 November 2023 |url-status=live}}</ref> As of 2017, the Technikmuseum Sinsheim remains the only museum in the world where the Tu-144 and Concorde are on display together.

==Accidents==

===Paris Air Show crash===
{{Main|1973 Paris Air Show Tu-144 crash}}
[[File:Tu144 Le Bourget en.svg|thumb|upright=2|Flight profile of Tu-144 and Mirage IIIR{{citation needed|date=June 2024}}]]
[[File:1973 06 Bourget TU144 (13).jpg|thumb|Tu-144 at the Paris Air Show, 2 June 1973, the day before the crash.]]
At the [[Paris Air Show]] on 3 June 1973, the development programme of the Tu-144 suffered severely when the first ''Tu-144S'' production airliner (reg 77102) crashed.<ref>{{cite AV media |url=https://www.youtube.com/watch?v=KWv3XcDrgI4 |title=Ce jour où le Tupolev Tu-144 s'est écrasé en plein Bourget |trans-title=The Day the Tupolev Tu-144 Crashed at Le Bourget |language=fr |date=3 June 1973 |publisher=[[Institut national de l'audiovisuel|INA]] |via=YouTube |access-date=13 November 2023 |archive-date=13 November 2023 |archive-url=https://web.archive.org/web/20231113143829/https://www.youtube.com/watch?v=KWv3XcDrgI4 |url-status=live }}</ref>

At the end of the officially approved demonstration flight, which was an exact repeat of the previous day's display, instead of landing as expected, the aircraft entered a very steep climb before making a violent downwards manoeuvre.<ref name="GordonKomissarovRigmant2015" />{{rp|228}} As it tried to recover, the aircraft broke apart and crashed, destroying 15 houses and killing all six people on board the Tu-144 and eight more on the ground.

Gordon et al.<ref name="GordonKomissarovRigmant2015" />{{page needed|date=November 2023}} state that the flight crew had departed from the approved flight profile for the display. They were under instructions to outperform the Concorde display by all means. During the unapproved, and therefore unrehearsed manoeuvres, the stability and control augmentation system was not operating. If it had been, it would have prevented the loads that caused the port wing to fail.

A popular Soviet theory for the crash was that the Tu-144 tried to avoid a French [[Dassault Mirage III|Mirage]] chase-plane that was attempting to photograph its [[canard (aeronautics)|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 Soviet crew was not told about the Mirage's flight), though not its role in the crash. 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".<ref name="nova98" />

Moon writes that the investigation was clouded by political considerations from the outset, and that an exoneration of the Tu-144 from a technical and design standpoint was in the interests of both countries, as France was seeking Concorde overflight rights from the Soviet Union.{{sfn|Moon|1989|pp=159–160}} Moon characterized the final accident report as being "remarkable more for what it omitted than what it included."{{sfn|Moon|1989|pp=171}}

===Yegoryevsk crash===
{{Main|1978 Yegoryevsk Tu-144 crash}}
On 23 May 1978, the Tu-144 supersonic passenger jet was to make a test flight before delivery to Aeroflot. At an altitude of 3,000 m, a fire started at the [[Auxiliary power unit|APU]] located in the port wing. A turn was made to return to the airport and both engines located in the right wing (engines no. 3 and 4) were shut down and the aircraft began to lose altitude. Fire trailed the aircraft and the cockpit filled with smoke. Subsequently, the no. 1 (outer left) engine failed. Six minutes after the fire started, the crew managed to belly-land the aircraft in a field near [[Yegoryevsk]].<ref>{{Cite web | url=http://www.tu144sst.com/fleet/06-2.html | title=Tu-144 SST : Aeroflot Fleet : 06-2 | access-date=4 April 2019 | archive-date=25 June 2019 | archive-url=https://web.archive.org/web/20190625235336/http://www.tu144sst.com/fleet/06-2.html | url-status=live }}</ref> On impact, the nose cone collapsed under the fuselage, penetrating the compartment in which two flight engineers were seated, killing both.<ref>{{Cite web|title=TU-144 SST : ACCIDENTS : CAUSE 06-2|url=http://www.tu144sst.com/accidents/cause06-2.html|access-date=6 May 2021|website=www.tu144sst.com|archive-date=6 May 2021|archive-url=https://web.archive.org/web/20210506153424/http://www.tu144sst.com/accidents/cause06-2.html|url-status=live}}</ref>
It was later determined that, 27 minutes prior to the ignition, a fuel line had ruptured, causing eight tons of fuel to leak into several compartments on the right wing. The fuel readings were judged incorrect by the flight engineers and thus were not reported to the commander.<ref>{{Cite web | url=https://aviation-safety.net/database/record.php?id=19780523-1 | title=ASN Aircraft accident Tupolev Tu-144D СССР-77111 Yegoryevsk | access-date=4 April 2019 | archive-date=4 April 2019 | archive-url=https://web.archive.org/web/20190404172112/https://aviation-safety.net/database/record.php?id=19780523-1 | url-status=live }}</ref> In addition to the two flight engineers killed on impact, six other crewmembers were injured.<ref>{{Cite web|title=TU-144 SST : ACCIDENTS|url=http://www.tu144sst.com/accidents/accidentsindex.html|access-date=6 May 2021|website=www.tu144sst.com|archive-date=29 April 2016|archive-url=https://web.archive.org/web/20160429074830/http://www.tu144sst.com/accidents/accidentsindex.html|url-status=live}}</ref> The Tu-144 was withdrawn from passenger service soon afterward, though a 2019 post-mortem by CNN reported that it was already "on its way out" before then.<ref name="III">{{cite web|url=https://www.cnn.com/style/article/tupolev-tu-144-concordski/index.html|title=Concordski: What ever happened to Soviets' spectacular rival to Concorde?|publisher=CNN Style|last=Prisco|first=Jacopo|date=10 July 2019|accessdate=26 November 2023|archive-date=10 November 2021|archive-url=https://web.archive.org/web/20211110085314/https://www.cnn.com/style/article/tupolev-tu-144-concordski/index.html|url-status=live}}</ref>

==Specifications (Tu-144D)==
[[File:Tupolev Tu-144LL 3-view line drawing.png|thumb|300px|Tu-144LL drawing]]
{{Aircraft specs
|ref=<ref>{{cite web|url=http://www.tu144sst.com/techspecs/dimensions.html|title=TU-144 SST : TECHNICAL SPECS : DIMENSIONS|website=www.tu144sst.com|access-date=9 January 2016|archive-date=11 July 2020|archive-url=https://web.archive.org/web/20200711043905/http://www.tu144sst.com/techspecs/dimensions.html|url-status=live}}</ref>{{verify source|date=January 2016}}
|prime units?=met
<!--
        General characteristics
-->
|crew= 3
|capacity= 150 passengers (11 first class & 139 tourist class)
|length m=65.7
|span m=28.8
|height m=12.55
|wing area sqm=506.35
|aspect ratio=<!-- sailplanes -->
|airfoil=<!--'''root:''' [[NACA airfoil|NACA]]; '''tip:''' [[NACA airfoil|NACA]]<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>-->
|empty weight kg=99200
|gross weight kg=125000
|max takeoff weight kg=207000
|fuel capacity={{convert|93000|kg|lb|abbr=on}}
|more general=
<!--
        Powerplant
-->
|eng1 number=4
|eng1 name= [[Kolesov RD-36-51]]
|eng1 type=turbojets
|eng1 kn=240
<!--
        Performance
-->
|max speed kmh=2500
|max speed note=
|max speed mach= 2.15
|cruise speed kmh=2125
|cruise speed note=
|stall speed kmh=
|never exceed speed kmh=
|minimum control speed kmh=
|range km=6500
|combat range km=
|ferry range km=
|endurance=<!-- if range unknown -->
|ceiling m=20000
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|climb rate ms=50
|time to altitude=
|wing loading kg/m2=410.96
|fuel consumption kg/km=
|thrust/weight=0.44
|more performance=
|avionics=
}}

==See also==
{{aircontent
|related=
* [[Tupolev Tu-244]]
* [[Tupolev Tu-444]]
|lists=
* [[List of jet airliners]]
|similar aircraft=*[[Concorde]]
* [[Boeing 2707]]
* [[Lockheed L-2000]]}}

==References==

===Notes===
{{Reflist|group=N}}

===Citations===
{{Reflist}}

===Bibliography===
* Gordon, Yefim. ''Tupolev Tu-160 Blackjack: The Russian Answer to the B-1'' (Red Star 9). Hinckley, Leicestershire, UK: Midland Publishing, 2003. {{ISBN|978-1-85780-147-7}}.
*{{cite book |last=Moon |first=Howard |date=1989 |title=Soviet SST: the technopolitics of the Tupolev Tu-144  |location=New York City |publisher=Orion Books |isbn=0-517-56601-X}}
* Taylor, John W.R. ''Jane's Pocket Book of Commercial Transport Aircraft'' New York: Macmillan, 1974. {{ISBN|978-0-02080-480-2}}.

==External links==
{{Commons category|Tupolev Tu-144}}
* [http://www.dfrc.nasa.gov/Gallery/Movie/TU-144LL/ NASA video clip] {{Webarchive|url=https://web.archive.org/web/20070429051127/http://www.dfrc.nasa.gov/Gallery/Movie/TU-144LL/ |date=29 April 2007 }}
* {{Internet Archive short film|id=gov.archives.arc.653130|name=Takeoff SST (Supersonic Transport Aircraft) (1969)}}
* {{cite news |url= https://www.cia.gov/library/readingroom/docs/DOC_0000620493.pdf |title= Soviet Supersonic: A Technopolitical Disaster |work= Studies in Intelligence |publisher= CIA |date=Winter 1984 |access-date= 28 May 2019 |archive-date= 28 November 2018 |archive-url= https://web.archive.org/web/20181128075317/https://www.cia.gov/library/readingroom/docs/DOC_0000620493.pdf |url-status= dead }}

{{Tupolev aircraft}}
{{Supersonic transport}}
{{USAF/DoD reporting names}}
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[[Category:Tupolev aircraft|Tu-0144]]
[[Category:1960s Soviet airliners]]
[[Category:Delta-wing aircraft]]
[[Category:Quadjets]]
[[Category:Canard aircraft]]
[[Category:Supersonic transports]]
[[Category:Aircraft first flown in 1968]]
[[Category:Aircraft with retractable tricycle landing gear]]
[[Category:Low-wing aircraft]]