Editing Tupolev Tu-144 (section)

===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"/>