The fuel for civil aviation jet engines is aviation kerosene. In the fuel systems of aircraft and aircraft engines, they perform a number of functions, one of the main ones being the lubricating function. The lubricity of fuels depends on many factors, including the technologies for their production, which are constantly changing. The lubricity of Russian fuels for civil aviation is not standardized and not controlled. A comparative assessment of the lubricity of fuel brands used in civil aviation on a four-ball friction machine is shown in the article. The introducing an indicator characterizing the lubricity of fuels into the Russian standard for jet fuels relevance is justified.

Special aviation gasoline with specified operational properties is used for aircraft piston engines. The level of operational properties indicators is specified by the special additives introduction. One of these additives is an antiknock additive – tetraethyl lead. The influence of tetraethyl lead contained in aviation gasoline on the oil systems of aircraft piston engines operation are shown in the article. The insignificant content of TEL decomposition products in aviation oils sharply worsens their pumpability and leads to complete fine oil filters clogging in a few minutes of engine operation, which is negative from the point of view of flight safety.

Today, technologies for the production of alternative fuels and for the development of engines on different operating principles are actively developing, due to both the tightening of the environmental requirements of ICAO (International Civil Aviation Organization) for harmful emissions into the atmosphere and the depletion of non-renewable resources, and the interests of the oil importing countries. Strict requirements are imposed on the quality of aviation fuels related to ensuring the reliability of aviation technology and flight safety. Requirement toughening for quality indicators will inevitably lead to higher fuel prices, so today we can observe some concessions in domestic and foreign regulatory documents to certain quality indicators of aviation fuels, for example, to indicators of low-temperature properties. It follows that the use of petroleum fuels will sooner or later become inappropriate. Technologies to produce synthetic and biological fuels from various types of raw materials make it possible to obtain fuel with close quality indicators to traditional kerosene, but it has not yet been completely replaced. Therefore, today we are considering the use of alternative fuels in a mixture with petroleum kerosene in various proportions. The question remains open: in what proportion is it possible to use mixtures of alternative fuel with kerosene on the aircraft without any negative consequences for their operation. Based on the known dependencies, a mathematical model is proposed for calculating some operational indicators of fuel, engine and aircraft depending on the proportion of mixing alternative fuel and kerosene. In accordance with the calculations, the most rational ratio of petroleum kerosene and SPK fuel is substantiated both from the point of view of the necessary operational properties and from the point of view of economic feasibility.

There are three main fuel brands for jet engines of civil aviation used: domestic TS-1 and RT and foreign, produced in relatively small volumes in Russia, JET A-1 (JET A-1). Since the end of the 2000s, foreign manufacturers have made claims to the quality of the mass-used domestic fuel brand TS-1, and these claims have not been specified. However, the service life of a number of foreign engines operating on TS-1 fuel has been reduced by 50%. This circumstance can be caused by both subjective reasons – commercial and political interests of equipment manufacturers, and the objective ones. The main objective reason may be that recently several Russian plants producing TS-1 fuel have begun to produce composite propellant under the same name, where products of secondary oil refining processes are added to the straight-run fractions. These fuels meet the requirements of the standard (GOST 10227-86), which does not contain an indicator that characterizes the anti-wear properties of jet fuels. In the standard for JET A-1 fuel, anti-wear properties are normalized, and they are also normalized in the standard for domestic fuels for supersonic aviation. The article presents comparative tests of anti-wear properties of samples of jet fuels used in the civil aviation. The article substantiates the relevance of the anti-wear properties indicator in the standard for domestic brands of jet fuels for subsonic aircraft introduction, as well as the comparative analysis of the anti-wear properties of fuels produced by various Russian oil refineries. Indicators and methods for assessing the anti-wear properties of aviation fuels can be different. As such an indicator, it is proposed to use the anti-wear properties indicator calculated after testing fuel samples on a four-ball friction machine.