It is a familiar story, but Russian engine makers are suffering from a shortage of funds.

Alexander Velovich/MOSCOW

OF ALL SECTORS IN THE Russian aviation industry, engine manufacturers are receiving probably the sharpest criticism from national media and airline operators for their apparent inability to offer products, which are competitive with state-of-the-art Western designs.

The engine at the centre of the highest level of controversy is the Aviadvigatel/Perm Motors PS-90A turbofan, which powers the Ilyushin Il-96-300 and Tupolev Tu-204 airliners. By the end of 1994, Russian operators had become so unhappy with the PS-90A that Vitaliy Yefimov, Russia's transport minister, made specific mention of it in a letter to Prime Minister Victor Chernomyrdin expressing his concern.

He said that the PS-90A engine's declared lifetime is 1,000h, but that the actual time between non-scheduled dismantlings is 300h - about 100 times lower than that of equivalent foreign engines, and 50 times lower than the required national standard. Yefimov concluded that the engine demands a huge number of design and manufacturing refinements.

Many of the problems with the PS-90 result from the mid-1980s competition between design bureaux Aviadvigatel and Kuznetsov/Trud in Samara (now renamed Dvigateli NK) for state financing of a new-generation engine for commercial aircraft. Aviadvigatel won the battle then, but probably by allowing over-high turbine-inlet temperatures in its design. Mikhail Kuzmenko, Aviadigatel general designer, says that the latest-model PS-90 will appear with its turbine inlet-temperature lowered significantly (by 30-40¡C), ensuring much better reliability and lifetime.

Two of the most serious problems, discovered in the course of PS-90 operations, are coking in the combustion chamber and software bugs in the full-authority digital engine-control system. The former problem appeared only after the PS90A-powered Il-96-300 began long-endurance flights to and from Southeast Asia. Alexander Inozemtsev, deputy general designer of Aviadvigatel, claims that coking was caused by jet fuel of low quality supplied in that region and that no tests in Russia have revealed the problem.

Inozemtsev explains the PS-90A problems by saying that the design is still being refined. Most of the engines in operation date back to pre-1992 production, he says, and do not, therefore, include design and manufacturing features introduced later.

Inozemtsev also complains about the unbalanced planning of production to meet orders of the PS-90A, which has resulted in Perm Motors producing 35-45 engines a year in 1990-2, 20 in 1993 and only two in 1994. "Such non-rhythmical production does nothing to help to improve quality and stability of operation," he says.


Aviadvigatel and Perm Motors have worked out a three-year staged programme of improvement for PS-90 performance, which has been approved by the transport ministry and the State Committee for Defence Branches of Industry (SCDBI). Aviadvigatel's Kuzmenko promises that a refined engine, with reliability increased by a factor of three, will be put into production before the end of August. The declared lifetime of the new engine is to be extended to 5,000h.

These procedures, however, require significant financing, and Inozemtsev says that, in the past two years, the SCDBI has provided only about one-third of what was needed to overcome difficulties with the engine. "Unfortunately, the only source of financing to solve these problems is the state budget. Other sources and private investors have not shown any interest," mourns the Aviadvigatel official.

In an attempt to solve some of these financial issues, a presidential decree was signed by Boris Yeltsin and issued on 18 May, establishing the Russian Aviation Consortium (RAC). The RAC has the status of a financial-industrial group and incorporates the Ulyanovsk Aviastar aircraft-production plant, Tupolev design bureau, Perm Motors and Perm Aviadvigatel, the Universal joint-stock company (owner of the Orel-Avia airline, operating Tu-204s) and the Promstroi Bank of Russia.

Yeltsin's decree grants state, guarantees for investment projects initiated by the RAC and approved by the Russian Government, postponing federal tax payments for the members of the consortium and returning dividends earned by the state, through its shares of the member companies exclusively, for purposes of developing civil aviation by RAC members.

In another move to improve organisational structures, Aviadvigatel and Perm Motors have announced the establishment of the Aviam joint-stock company, to streamline production of the PS-90 turbofan and further development of its derivatives. Aviadvigatel will acquire shares of the new company worth about $10 million in rouble equivalent, mostly passing on the rights to use design documentation and inventions implemented in the PS-90 design.

Perm Motors is to acquire a 29% share in Aviadvigatel, strengthening the integration of the design bureau and production plant. It is also planned that Aviam and Pratt & Whitney of the USA will form a joint venture to develop and produce the PS-90P, the new model with refinements introduced on the basis of P&W technological expertise. Andrei Malyutin, an Aviadvigatel member of the board, says that the Russian-American joint venture will be registered this September.

According to the US Company, P&W and its Western partners will invest over $125 million in this project. To try to develop improvements quickly, P&W parent corporation UTC has already invested about $10 million, and expects to spend $19 million more during 1995, if the joint-venture agreement enters the registration process soon.

Vladimir Kinderknecht, Perm Motors general director, believes that the PS-90 will continue to be competitive, especially in Russia, because of its low price, which is now estimated to be roughly $1.5 million in rouble equivalent - at least five times less than the price of any competing Western engine.


At the time of the 1980s competition, Dvigateli NK (then known as Samara) chose a more innovative approach to engine development with its NK-93 shrouded propfan. The objective at the beginning of the project was to develop a 175kN (39,600lb) high-bypass engine for subsonic transport aircraft with high fuel efficiency of 0.49 kg/kgf/h in cruise conditions. The development of the NK-93 began in 1987, with testing starting in 1989.

The prop-fan engine now under development in Samara is a 17:1-bypass geared power plant, which features two synchronised counter-rotating integrally shrouded propfans. About 87% of the thrust comes from the prop-fans, while the gas generator produces the rest. Seven complete test engines have been assembled since 1989.

The NK-93's forward prop-fan rotates clockwise, while the aft prop-fan rotates counter-clockwise. Each is driven by a separate shaft from the power plant's 22,350kW (30,000hp) planetary gearbox, which has seven satellites. There have been problems in developing a gearbox of this size with adequate bearing durability, oil distribution and gear-teeth strength. These problems, are claimed to have been solved. The planetary gearbox is being designed for a service life of 20,000h, and time between overhauls should be about 7,500h.

By the end of 1994, Samara had accumulated 2,800 test hours, including the tests of the NK-110, the gas-generator prototype, and 1,700h of testing on the NK-93 and its components. The required take-off thrust of 176kN has been achieved with specific fuel consumption of 0.234kg/kgf/h. Turbine-inlet temperatures of 1,700¡C have been achieved, along with a mass airflow of 976kg/s, a gas generator pressure ratio of 25:1, a maximum thrust of 200kN, reverse thrust of 37kN and shaft rotation speeds of 1,580RPM; 11,270RPM and 15,480RPM for each of the shafts respectively.

A department head at Dvigateli NK says that, in 1995-6, the NK-93 is to be tested at the barometric chambers of the TsIAM Central Aviation Motors Institute at Turayevo, to obtain speed-altitude characteristics. After that, the engine may be installed on an Ilyushin Il-76 testbed.

The programme has not received sufficient financial backing from the state budget and is "running on enthusiasm", according to another Dvigateli NK official. The flight tests, initially planned for 1994, have been delayed for three years. One source at Samara says that, technically, he does not see any difficulties in taking the engine to its production phase, despite finance being provided at a fraction of what is really needed.

Another area of extensive design and development by Dvigateli NK is the NK-89 dual-fuel engine, which is capable of burning not only aviation kerosene, but liquefied natural gas. The idea of using alternative fuels is explained by large natural-gas resources, in the northern part of Siberia, where air transport is often the only means of travel. Yevgeniy Gritsenko, Dvigateli NK general designer, says that, on a typical flight, an aircraft equipped with dual-fuel engines would burn ordinary jet fuel on its way to gas fields in Siberia, and would return having filled its tanks with liquefied natural gas.

In April 1994, the Russian Government issued a resolution on the development of the Tupolev Tu-156 cargo/passenger aircraft, powered by NK-89 engines, consuming cryogenic natural-gas fuel. The aircraft will be a modified Tu-154M, with maximum take-off weight of around 100t, maximum commercial load of 14.6t and operational range with maximum payload of 3,450km (1,850nm). Specific fuel consumption is targeted at 400g/ton/km. Fuel tanks would be installed on both sides of the fuselage over the wing.

The aircraft would become operational in 1997, when three Tu-156s are to be produced at the Samara production plant. Certification tests should be completed in the same year, and the transport ministry has been ordered to take the airliners in service for operational test evaluation d further development. Twelve NK-89 engines, further derivatives of NK-8U and NK-88 engines, should be produced at the Kazan engine plant and complete certification tests are scheduled for 1997. Six sets of cryogenic fuel systems will be produced by Dvigateli NK in Samara.

The Obshchemash design bureau is developing airfield equipment for cryogenic natural-gas fuel. This equipment will be installed at Ramenskoye (Zhukovsky) flight test centre, Domodedovo Airport of Moscow, and Ukhta Airport in Siberia, by 1996. In 1997, another set of ground equipment should be installed at Samara Airport.


The financing for the Russian Tu-156 project is to be provided "...within the limits of the state budget allocated to the Federal Program of Civil Aviation Development up to the year 2000", using funds allocated for "conversion".

The Russian ministry of finance and the economics ministry were ordered to provide money from the state budget for the purchase of three Tu-154Ms and 12 NK-8-U engines for further modification, with one aircraft and three engines to be paid for and delivered in 1994. Lack of money prevented this, however.

According to Gritsenko, all the major components which distinguish the NK-89 from an ordinary NK-8U have been manufactured and tested, including a dual-fuel combustion chamber, heat exchanger with a liquid natural-gas fuel gasifier, and turbo-pump with the turbine driven by compressed air taken from the engine compressor.

The fuel-feed system has been tested, as well as the combustion chamber, including transition processes from one fuel to another. According to test measurements, pollution from the combustor burning natural gas is over two times lower than while burning ordinary aviation kerosene because of the lower flame-temperature in the combustion area.

Further use of natural gas may come with the NK-93 shrouded prop-fan, and such a modification is being developed. It is reported that Tupolev is working on a Tu-214 airliner, a derivative of Tu-204, which would be powered with dual-fuel derivatives of the NK-93 engines, but this may occur only if the production of the engine itself takes off.

While the combined decibel level of moans from Russian engine-industry leaders complaining about the lack of financing probably exceeds the roar of jet engines on take-off, Victor Chepkin, the head of the Saturn/Lyulka design bureau in Moscow, says that his company does not have problems with money. "Too many of my colleagues who are used to working on state projects cannot see that it is time to stop begging from the state and to earn money for themselves", he says.

"In our firm it is forbidden to walk around ministries and beg for money. I never did it myself and I prohibit my deputies to do it," adds Chepkin.

He says that this attitude is not determined by a lack of respect for state bodies, but by a need to mobilise his company's own resourcefulness. "If one is promised help, one then just sits and waits for it instead of actively seeking ways out of a difficult situation. As a rule, such promises cannot be fulfilled. The state does not have the money now," he says.


In 1991, Saturn/Lyulka received 95% of its revenue from state defence orders. This figure is no more than 15% now, according to Chepkin. "The design bureau did not receive a single kopeck for conversion from the state and, strangely enough, now we do not have any particular problems with financing," Chepkin states proudly.

This does not mean that the company does not have problems, along with the usual set of Russian troubles, such as delays in contract payments, difficult relations with banks and high interest rates on bank loans, are applied to Saturn/Lyulka as well. "After all, we live not in paradise, but in Russia," summarises Chepkin.

To formalise its self-dependence, in April Saturn/Lyulka achieved the full status of a public joint-stock company, and only 20% of its shares now remain in state ownership. Even this last stake has to be sold this year. Up to 51% of the shares were sold for a symbolic price to the company's employees, and 29% at a privatisation auction. Now, there are 1,400 shareholders of the design bureau, and Chepkin stresses that the shareholders' meeting is the only authority to report to.

"It is very important to us, because it makes a huge difference to make decisions ourselves and to carry them out, rather than to follow the orders of [state] functionaries," says Chepkin, whose business card names him president and chief executive officer, posts to which he was elected, not appointed.

Major areas of Saturn/Lyulka activities include development of the AL-41 military turbofan, a pair of which power the Mikoyan MFF (Multifunctional Frontline Fighter), or "Article 1.42", the Russian counterpart to the US Air Force Lockheed Martin F-22.

The bulk of revenues for the bureau come from several diversification programmes, and industrial turbines based on the AL-31 in particular. The AL-31ST is used in gas-pumping stations and the AL-31STE drives the 20MWt electric generator of a modular power station, which includes also a waste-heat boiler utilising gas exhaust.

Commenting on the emerging alliances of Russian engine manufacturers with Western companies, which are supposed to introduce Western know-how into Russian designs, Chepkin says that "...there is hardly anyone to teach us anything in the field of military engines", in which the Saturn/Lyulka bureau is specialising.

On the lines of its emphasis on industrial turbines, which generate up to 65% of revenues for the company now, Saturn/Lyulka has found a foreign partner, the Swiss-Swedish company ABB, a leading manufacturer of industrial turbines. A joint venture established with ABB, based in Moscow, already employs 400 workers.

Saturn/Lyulka's self-dependent approach also showed itself once again when the company issued a contract to Rolls-Royce for the development of a combustion chamber with low exhaust-emission, to meet ecological requirements for a future industrial engine based in rural areas. So far, it is the only example of a Russian engine manufacturer investing in a Western company to gain access to modern technology.

Chepkin says that, when the issue was brought up at a meeting with R-R, the R-R representatives, thinking that there must have been a mistake in translation, did not understand initially that it was Saturn/Lyulka which was to pay the money for the development, and not vice versa.

Giving a general outlook of the situation in the Russian engine, and even the aviation, industry, Chepkin concludes: "The thought of survival as the major current task widely spread in this country's industry. In our company, the use of the word 'survival', is prohibited by a special order because it is necessary, not to survive, but to live, and to live in the new environment, because there is no way to turn back to the old one."

There is little doubt that at least part of the Russian engine industry will survive, but it will require the full strength of traditional Russian resourcefulness to reduce the number of casualties on its way to a potentially bright future.

Source: Flight International