Search Results

Over the past several years the FZG A/8.3/90 test method has been used to evaluate current qualified aviation lubricants. The results of the effort have been summarized in this document as a historical reference to document the findings made from the committee.

This test method describes a standardized process to evaluate the an aviation lubricant’s resistance to oxidation and corrosion-based degradation and to evaluate the fluid’s tendency to corrode various metals. Fluids are evaluated under a low-moisture atmosphere at a variety of times and temperatures.

There has been a recent upsurge in interest from the media concerning the quality of the environment within aircraft cabins and cockpits especially in the commercial world. This has included (although by no means been limited to) the air quality, with particular reference to the alleged effects of contamination from the aircraft turbine lubricant. Possible exposure to 'organophosphates' (OPs) from the oil has raised special concerns from cabin crew. Such is the concern that government organisations around the world, including Australia, USA and UK, have set up committees to investigate the cabin air quality issue. Concern was also voiced in the aviation lubricants world at the way in which OP additives in turbine lubricants were being blamed in some reports for the symptoms being experienced by air crew and passengers. SAE Committee E-34 therefore decided that it should gather as much available information on the subject as possible.

This SAE Aerospace Information Report (AIR) establishes guidance for the specification of formulated lubricant properties which contribute to the lubricating function in bearings, gears, clutches and seals of aviation propulsion and drive systems.

This AIR establishes guidance for the specification of formulated lubricant properties which contribute to the lubricating function in bearings, gears, clutches and seals of aviation propulsion and drive systems.

This SAE Aerospace Information Report (AIR) establishes guidance for the specification of formulated lubricant properties which contribute to the lubricating function in bearings, gears, clutches, and seals of aviation propulsion and drive systems.

This method is designed to evaluate the micropitting performance of currently available and future aviation turbine oil formulations. Drawing on previously performed tests documented in AIR6989, the method comprises of three rings rotating against a rotating central roller configuration using the standard, commercially available PCS Instruments Micropitting Rig (MPR). A test profile has been developed between industry and academia that relies on standard, commercially available test specimens.

This AIR describes the current scientific and engineering principles of gas turbine lubricant performance testing per AS5780 and identifies gaps in our understanding of the technology to help the continuous improvement of this specification.

The test method describes the procedure for the direct determination of water concentration in polyol ester and diester based aerospace lubricants by commercially available automated coulometric Karl Fischer titration instruments. The method was validated to cover the water concentration range of 150 to 3500 µg/g. The method may also be suitable for the determination of water concentrations outside this range and for other classes of fluids; however, the precision statement shall not be applicable for such uses.

Aviation oils provide thin lubricating films between highly stressed bearing, gear and other lubricated contacts. The stresses and shear rates cause rapid rheological changes in the oil which affect the traction (friction) between the surfaces. Thin film dynamic forces are associated with the molecular structure of the oil provided by the oil supplier. Traction force divided by the normal load (i.e. traction coefficient) can be viewed as a fundamental property of aviation oil. Its value is a function of stress, temperature and shear rate. Appropriate measurements are made under dynamic conditions to characterize aviation oil products for engineering design purposes and service performance prediction.

The intent of this SAE Aerospace Information Report (AIR) is to summarize and review the E34 committee’s efforts to educate the aerospace propulsion lubrication community on the science of micropitting, its consequences, and the various tribology evaluation methods that can be employed under aviation related conditions to differentiate formulation related aggravating factors.

This method is intended to evaluate the thermal and oxidative stability of synthetic, ester-based aviation lubricants under defined conditions of time and temperature. This method is applicable to lubricants meeting the compositional and performance requirements of AS5780.

This method is designed to evaluate the coking propensity of synthetic ester-based aviation lubricants under two phase air-oil mist conditions as found in certain parts of a gas turbine engine, for instance, bearing chamber vent lines. Based on the results from round robin data in 2008-2009 from four laboratories, this method is currently intended to provide a comparison between lubricants as a research tool; it is not currently a satisfactory pass/fail test. At this juncture a reference oil may improve reproducibility (precision between laboratories); a formal precision statement will be given when there is satisfactory data and an agreed on, suitable reference oil if applicable.

Employing ‘ball-on-cylinder’ philosophy, a non-rotating steel ball is held in a vertically mounted chuck and using an applied load is forced against an axially mounted steel cylinder. The test cylinder is rotated at a fixed speed while being partially immersed in a lubricant reservoir. This maintains the cylinder in a wet condition and continuously transports a lubricating film of test fluid to the ball and cylinder interface. The diameter of the wear scar generated on the test ball is used as a measure of the fluid’s lubricating properties. The apparatus can be used, by adjusting the operating conditions, to reproduce two different wear mechanisms; mild and severe wear, the ALTE therefore has the ability to assess a lubricant’s performance in that regard.

The lubricant performance capability for aero propulsion drive systems is derived from the physical properties of the oil and performance attributes associated with the chemical properties of the oil. Physical properties, such as viscosity, pressure-viscosity coefficient and full-film traction coefficient are inherent properties of the lubricating fluid. Chemical attributes are critical for the formation of protective boundary lubricating films on the surfaces to prevent wear and scuffing. These attributes are also associated with surface initiated fatigue (micropitting). To assure performance and to provide required information for engineering design, methodology for at least five oil properties are being studied: (1) pressure-viscosity coefficient, (2) full-film traction coefficient, (3) scuffing resistance, (4) wear resistance, and (5) micropitting propensity.

This test method is designed to simulate the synergistic combinations of oil flow, temperature cycling, hot spots, and tribology that would typically be found in a gas turbine engine. The method is intended to quantitatively characterize changes in four basic oil properties that are brought about by exposure to the afore mentioned simulated turbine engine environment: the tendency of aviation lubricants to form coke deposits, viscosity changes, total acid number changes (TAN), and oil consumption.

This SAE Aerospace Information Report (AIR) establishes guidance for the specification of formulated lubricant properties which contribute to the lubricating function in bearings, gears, clutches, and seals of aviation propulsion and drive systems.

This method is designed to evaluate the coking propensity of synthetic ester-based aviation lubricants under single phase flow conditions found in certain parts of gas turbine engines, for instance in bearing feed tubes. This method is applicable to lubricants with a coking propensity, as determined by this method, falling in the range 0.01 to 5.00 mg.

This specification defines basic physical, chemical, and performance limits for 5 cSt grades of gas turbine engine lubricating oils used in aero and aero-derived marine and industrial applications, along with standard test methods and requirements for laboratories performing them. It also defines the quality control requirements to assure batch conformance and materials traceability, and the procedures to manage and communicate changes in oil formulation and brand. This specification invokes the Performance Review Institute (PRI) product qualification process. Requests for submittal information may be made to the PRI at the address in Appendix D Section D.2, referencing this specification. Products qualified to this specification are listed on a Qualified Products List (QPL) managed by the PRI. Additional tests and evaluations may be required by individual equipment builders before an oil is approved for use in their equipment.

This specification defines basic physical, chemical, and performance limits for 5 cSt grades of gas turbine engine lubricating oils used in aero and aero-derived marine and industrial applications, along with standard test methods and requirements for laboratories performing them. It also defines the quality control requirements to assure batch conformance and materials traceability, and the procedures to manage and communicate changes in oil formulation and brand. This specification invokes the Performance Review Institute (PRI) product qualification process. Requests for submittal information may be made to the PRI at the address in Appendix D Section D.2, referencing this specification. Products qualified to this specification are listed on a Qualified Products List (QPL) managed by the PRI. Additional tests and evaluations may be required by individual equipment builders before an oil is approved for use in their equipment.