Finished Lubricants

Aviation Oils


MOSCOW – The job of engine lubricants is critical in planes and other aircraft, since many lives as well as costly equipment depend on safe operation. But Russian engine oils for civil and military planes are not meeting the performance levels that they should, according to an official at the countrys leading aviation research center.

Vasily Yezhov, head of the fuels and lubricants laboratory at the Central Aerohydrodynamic Institute, told an industry conference here in November that domestic oils are hurt by a number of factors – from a lack of technical expertise to obsolete standards and an absence of in-country raw materials.

Speaking at the Lubricants Russia conference organized by RPI, Yezhov went on to recommend several steps which he argued would raise the quality of domestic oils. But he cautioned that some of the problems will take significant work and commitment, and that improvement will take time.

Performance Critical

Russias aviation industry has had an especially poor safety record over the past decade. During that period, the countrys airlines suffered at least six deadly crashes. The most infamous, an April 2010 crash landing in Smolensk, Russia, killed 154 people including Polish President Lech Kaczynski and a score of Polands top political and military leaders.

Certainly many things can contribute to plane crashes, and Russian investigators have cited a range of causes for accidents since the collapse of the Soviet Union, from poor flight plans, possible crew incompetence, obsolete equipment and poor maintenance. In two of the cases over the past 10 years, investigators cited lubrication as a factor in the crash. On 24 July 2009, an A-52 plane on a test flight crashed at an airport in Saratov, in southern Russia, after an engine failed. Investigators said the accident, which killed the pilot and co-pilot, occurred after a warning light indicated that metal shavings had been detected in the engine oil.

On 11 July 2011, an Anotov An-24 was forced to ditch in the Ob River in Tomsk oblast after a fire broke out in one of its engines. Once again, investigators reported that sensors had detected metal shavings in the engine oil. In that incident six people died and 20 were injured. It is worth noting that these findings did not indicate the source or cause of the metal shavings – for example whether they resulted from oil not being changed often enough as opposed to a substandard oil.

Nevertheless, Leonid Yanovskiy, head of the Central Aerohydrodynamic Institutes engines, fuels and lubricants department, said that engine oil quality is one area where Russias aviation industry is not up to par and that improvements are necessary to help protect equipment. The industry has to develop new lubricants with higher operational properties, he said during an early June interview at CIAMs offices in Moscow.

CIAM officials emphasize that Russian aviation oils are not inferior to foreign products in all aspects. The institute found that some Russian oils provided better antiwear and extreme pressure performance than Western counterparts. However oils made by Western companies demonstrate better thermal-oxidative stability, Yanovskiy said, adding that this is the parameter where Russian oils need the most improvement.

Lubricants for turboshaft engines should maintain their oxidative stability at up to 240 to 250 degrees C, he said. He added that complex polyol esters are a good choice for base stocks because they remain stable up to 260 degrees and have high viscosity index and good lubrication properties.

Multiple Problems

CIAM contends that Russias aviation industry has several problems that hamper its ability to develop high-quality synthetic engine oils. The first and very important issue is the lack of finances for scientific research and development projects and the lack of high-skilled personnel, Yanovskiy said. Equipment on which to test aviation oils can be very expensive, he explained, and trials to verify oil performance long and costly.

A related but separate problem, he said, is that Russia also lacks a technical foundation and test methods for evaluating the performance of aviation oils. Russia and other members of the Commonwealth of Independent States do have aviation oil specifications under the GOST umbrella of standards, but those specifications have not kept pace with aircraft engine technology and are now obsolete, Yanovskiy said.

The industry has a voluntary system – developed by NIISU, the Moscow-based state scientific enterprise for standardization and unification – to certify manufacturers of aviation oils. However, the NIISU program, which is similar to ISO quality standards, speaks only to the quality of manufacturing processes, and does not consider the formula of the lubricants or whether they meet performance requirements of the aircraft in which they are used.

Every manufacturer is not obliged to pass the certification, Yezhov said. But owning the national certificate is a proof of certain quality. Marketing results inside Russia without such a certificate would be poor for every aviation oils producer.

CIAM tests imported aviation oils and every fifth year publishes a brochure with a long list of types of aviation oils recommended for use in Russian aviation equipment. We have published the results in our so-called Green Book for four decades now, Yanovskiy said. Since Soviet times we have tested all international oils imported to Russia, and we issue permission to engine manufacturers to use those aviation oils that have the same or better quality than Soviet-made aviation oils meeting GOST standards.

This is voluntary and [the system] is not enforced anymore. We are using many of the same procedures, [but] the technical demands of aviation oils have become much more restrictive over the years, so we need to improve our test methods.

CIAM says Russia also suffers from a lack of supply chain for ingredients needed to make effective aviation oils. The institute believes temperatures of modern civil and military aircraft require oils made with synthetic ester base stocks, but such fluids are not produced in Russia. Yanovskiy explained that a few companies made them in the past, but stopped doing so because of scarce demand.

Ester demand was very low in the 1990s, production became unprofitable, so it simply stopped, he said. Since then, the countrys ester demand has been satisfied with imports.,

As a result, Russian companies that want to make aviation oils need to import base stocks. A few do this, including Specnefteprodukt and Nika, companies that are based in Ryazan and Moscow, respectively. But Yanovskiy said importing has disadvantages. First, it is difficult to find reliable suppliers that can supply the needed material on a consistent basis. As a result, Russian companies end up purchasing on a spot basis.

There are problems in terms of the quality of imported esters, Yanovskiy said. Different suppliers mean variations in ester quality. Sometimes companies buy from middle men and there have been cases when they bump into counterfeit products.

Sometimes Russian companies have resorted to purchasing esters that require additional processing to achieve performance levels needed for aviation oils. But this drives up costs to the point that Russian aviation oils cost more than imported products, so end users are more inclined to use imports.

It is possible to purchase Russian made additives for aviation oils, but these generally do not yield good results when mixed with imported ester base stocks, Yanovskiy said. As a result, lube blenders are better off importing additives, too.

Call for Action

During his presentation at the RPI conference, Yezhov called for a number of actions which he said are necessary to raise the quality of Russian aviation oils. First, he said, multiple projects are needed to research and develop lubricants for the next generation of turboshaft engines. The institute contends it will be critical to ensure excellent high temperature performance because operating temperatures are rising.

The industry will need specifications to define performance requirements for those oils. Rather than reviving GOST specifications as separate standards, CIAM recommends harmonizing Russian requirements with international standards.

The general opinion is that our oils technical standards should be harmonized with the international standards, Yezhov said

This is not something that can be done quickly or immediately because of differences in language, test methods and practices, products and some remaining differences in aircraft design. Fortunately, equipment technologies of Russia and the West are now converging.

Aviation development trends in Russia and elsewhere are becoming similar, Yanovskiy said. Still, he emphasized that harmonization will not be easy and will take Russia some time to accomplish because the country lacks test methods and bench testing equipment. This bench equipment has to be purchased from the West, or it has to be made in Russia. And if it is made in Russia, it still has to be completely compatible with the Western testing benches and test methods.

The harmonization should be done together with the Ministry of Defense and Ministry of Civil Aviation, Yanovskiy continued. It should include a system for applying for and obtaining approvals. It also needs to define lab and bench tests [that candidate oils must pass], as well as practices to ensure the accuracy of the equipment on which the tests are conducted. Of course, these tests should simulate the real-time operating conditions of the newest aircraft engines.

Finally, Yanovskiy said it would aid the domestic industry if manufacturers of aviation lubes could tap domestic suppliers for raw materials.

Establishment of domestic production of esters for aviation oils is much more convenient, both in terms of cost effectiveness and in technical aspects, he said. It allows us better