Tupolev Tu-144

Tu-144

This Tu-144LL was the only Tu-144 that was used by NASA to design the High Speed Civil Transport
Role	Supersonic airliner
Manufacturer	Tupolev OKB
Designed by	Alexei Tupolev
First flight	31 December 1968
Introduction	26 December 1975
Retired	1 June 1978
Primary user	Ministry of Aviation Production
Number built	16

The Tupolev Tu-144 (NATO name: "Charger") was the world's first supersonic transport aircraft (SST, with its first flight preceding that of Concorde), constructed under the direction of the Soviet Tupolev design bureau headed by Alexei Tupolev.

A prototype first flew on 31 December 1968 near Moscow, two months before the similar Aérospatiale / British Aircraft Corporation Concorde. The Tu-144 first broke the speed of sound on 5 June 1969, and on 15 July 1969 it became the first commercial transport to exceed Mach two, and it was at the time the fastest commercial-type airliner.

The Tu-144 was Tupolev's only supersonic commercial airliner venture. Tupolev's other large supersonic aircraft were designed and built to military specifications. All these aircraft benefited from technical and scientific input from TsAGI, the Central Aerohydrodynamic Institute.

Design and development

The Soviets published the concept of the Tu-144 in an article in the January 1962 issue of the magazine Technology of the Air Transport. The air ministry started development of the Tu-144 on 26 July 1963, following approval by the Council of Ministers 10 days earlier. The plan called for five flying prototypes to be built in four years. The first aircraft was to be ready in 1966.

Despite the close similarity in appearance of the Tu-144 to the Anglo-French supersonic aircraft, there were significant differences in the control, navigation and engine systems. The Tu-144 was in some ways a more technologically advanced aircraft, but in areas such as range, aerodynamic sophistication, braking and engine control, it lagged behind Concorde. While Concorde utilized an electronic engine control package from Lucas, Tupolev was not permitted to purchase it for the Tu-144 as it could also be used on military aircraft. Concorde's designers used the fuel of this airliner as the coolant for air conditioning the cabin and the hydraulic system (see Concorde#Heating issues for details). Tupolev installed additional equipment on the Tu-144 to accomplish this, increasing the weight of that airliner. One important offshoot of this was that while Concorde could supercruise (maintain supersonic flight without using its afterburners), the Tu-144 could not. Later work on the Tu-144S did resolve this shortcoming.

Tupolev continued to work to improve the Tu-144. Many substantial upgrades and changes were made on the Tu-144 prototype (serial number 68001). While both Concorde and the Tu-144 prototype had ogival delta wings, the Tu-144's wing lacked Concorde's conical camber. Production Tu-144s replaced this wing with a double-delta wing including conical camber, and they added an extra simple but practical device: two small retractable canard surfaces on either side of the forward section on the aircraft to increase lift at low speed.

Moving the elevons downward in a delta-wing aircraft increases the lift, but that also pitches its nose downward. The canard cancels out this nose-downwards moment, thus reducing the landing speed of the production Tu-144s to 315-333 km/h (170-180 kn, 196-207 mph) - however, still faster than that of Concorde.

Paris Air Show crash

At the Paris Air Show on 3 June 1973, the development program of the Tu-144 suffered severely when the first Tu-144S production airliner (reg 77102) crashed. While in the air, the Tu-144 underwent a violent downwards maneuver. Trying to pull out of the subsequent dive, the Tu-144 broke up and crashed, destroying 15 houses and killing all six people on board the Tu-144 and eight more on the ground.

The causes of this incident remain controversial to this day. A popular theory was that the Tu-144 was forced to avoid a French Mirage chase plane which was attempting to photograph its canards, which were very advanced for the time, and that the French and Soviet governments colluded with each other to cover up such details. The flight of the Mirage was denied in the original French report of the incident, perhaps because it was engaged in industrial espionage. More recent reports have admitted the existence of the Mirage (and the fact that the Russian crew were not told about the Mirage's flight) though not its role in the crash. However, the official press release did state: "though the inquiry established that there was no real risk of collision between the two aircraft, the Soviet pilot was likely to have been surprised."

Another theory claims that the black box was actually recovered by the Soviets and decoded. The cause of this accident is now thought to be due to changes made by the ground engineering team to the auto-stabilisation input controls prior to the second day of display flights. These changes were intended to allow the Tu-144 to outperform Concorde in the display circuit. Unfortunately, the changes also inadvertently connected some factory-test wiring which resulted in an excessive rate of climb, leading to the stall and subsequent crash.

A third theory relates to deliberate misinformation on the part of the Anglo-French team. The main thrust of this theory was that the Anglo-French team knew that the Soviet team were planning to steal the design plans of Concorde, and the Soviets were allegedly passed false blueprints with a flawed design. The case, it is claimed, contributed to the imprisonment by the Soviets of Greville Wynne in 1963 for spying. Wynne was imprisoned on 11 May 1963 and the development of the Tu-144 was not sanctioned until 16 July. In any case, it seems unlikely that a man imprisoned in 1963 could have caused a crash in 1973.

Operational service

The Tu-144S went into service on 26 December 1975, flying mail and freight between Moscow and Alma-Ata in preparation for passenger services, which commenced in November 1977 and ran a semi-scheduled service until the first Tu-144D experienced an in-flight failure during a pre-delivery test flight, and crash-landed with crew fatalities on 23 May 1978. The Aeroflot flight on 1 June 1978 was the Tu-144's 55th and last scheduled passenger service.

A scheduled Aeroflot freight-only service recommenced using the new production variant Tu-144D (Dal'nyaya - long range) aircraft on 23 June 1979, including longer routes from Moscow to Khabarovsk made possible by the more efficient Kolesov RD-36-51 turbojet engines used in the Tu-144D version, which increased the maximum cruising speed to Mach 2.15. Including the 55 passenger flights, there were 102 scheduled Aeroflot flights before the cessation of commercial service.

It is known that Aeroflot still continued to fly the Tu-144D after the official end of service, with some additional non-scheduled flights through the 1980s. One report showed that it was used on a flight from the Crimea to Kiev in 1987.

Production

A total of 16 airworthy Tu-144s were built: the prototype Tu-144 reg 68001, a pre-production Tu-144S reg 77101, nine production Tu-144S reg 77102 – 110, and five Tu-144D reg 77111 – 115. A 17th Tu-144 (reg 77116) was never completed. There was also at least one ground test airframe for static testing in parallel with the prototype 68001 development.

The Tu-144S model had Kuznetsov NK-144 turbofan engines and could not cruise at Mach 2 without the afterburner on: a maximum cruising speed of Mach 1.6 was possible on "dry" power (afterburner off). The turbofan engines suffered from heavy fuel consumption, and this limited range to about 4,000-4500 km (2,160-2,430 nmi, 2,485-2,796 mi), depending on payload, far less than Concorde's turbojets.

The later experimental Tu-144D model featured more powerful Kolesov RD-36-51 turbojet engines with much better fuel efficiency (particularly during supercruise where it was comparable to Concorde's Olympus engines although it did not require afterburner) and it gave longer range up to ~6,200 km (3,348 nmi, 3,853 mi). Plans for an aircraft with 7,000+ km (3,780 nmi, 4,350 mi) range were never implemented.

Along with early Tu-134s, the Tu-144 was one of the last commercial aircraft with a braking parachute.

Post-production uses

Although its last commercial passenger flight was in 1978, production of the Tu-144 did not cease until six years later, in 1984, when construction of the partially complete Tu-144D reg 77116 airframe was stopped. During the 1980s the last two production aircraft to fly were used for airborne laboratory testing, including research into ozone depletion at high altitudes.

In the early 1990s, a wealthy businesswoman, Judith DePaul, and her company IBP Aerospace negotiated an agreement with Tupolev and NASA, (also Rockwell and later Boeing). They offered a Tu-144 as a testbed for its High Speed Commercial Research program, intended to design a second-generation supersonic jetliner called the High Speed Civil Transport. In 1995, Tu-144D [reg 77114] built in 1981 (but with only 82 hours and 40 minutes total flight time) was taken out of storage and after extensive modification at a total cost of US$350 million was designated the Tu-144LL (Russian: Летающая Лаборатория — where LL is an abbreviation for Flying Laboratory). It made a total of 27 flights in 1996 and 1997. In 1999, though regarded as a technical success, the project was cancelled for lack of funding.

The Tu-144LL was reportedly sold in June 2001 for $11 million via online auction, but the aircraft sale did not proceed after all — Tejavia Systems, the company handling the transaction, reported in September 2003 that the deal was not signed. The replacement Kuznetsov NK-321 engines (from the Tupolev Tu-160 bomber) are military hardware and the Russian government did not allow them to be exported.

At the 2005 Moscow Air & Space Show, Tejavia founder Randall Stephens found the Kuznetsov NK-321 engine on display, and the Tu-144LL rusting on Tupolev's test base at the Gromov Flight Test Center. In late 2003, with the retirement of Concorde, there was renewed interest from several wealthy individuals who wanted to use the Tu-144LL for a transatlantic record attempt; but Stephens advised them of the high cost of a flight readiness overhaul even if military authorities would authorize the use of NK-321 engines outside Russian Federation airspace.

The last two production aircraft remain at the Tupolev production plant in Zhukovsky, reg 77114 and 77115. In March 2006, it was announced that these airframes had been sold for scrap. Later that year, however, it was reported that both aircraft would instead be preserved. One of them could be erected to a pedestal near Zhukovsky City Council and TsAGI or above the LII entrance from the Tupolev avenue.

Civil operators

While several Tu-144s were donated to museums in Moscow Monino, Samara and Ulyanovsk, at least two Tu-144D remained in open storage in Moscow Zhukovsky.

The only Tu-144 on display outside the former Soviet Union was acquired by the 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.

Specifications

These are the specification for the later experimental version the Tu-144D which employs the more efficient turbojet engines.

Image Gallery

Other mentions

The jet liner was mentioned in the 1987 Phoenix Force adventure book series Weep, Moscow. Weep.