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This test method describes a standardized process to evaluate an aviation lubricant’s resistance to thermal degradation and to evaluate the fluid’s tendency to corrode a steel specimen. Fluids are evaluated in an environment free of both air and moisture at a specified temperature and for a specified time period.

The test method describes the procedure for determination of the total acid number (TAN) of new and degraded polyol ester and diester-based gas turbine lubricants by the potentiometric titration technique. The method was validated to cover an acidity range of 0.05 to 6.0 mg KOH g-1. The method may also be suitable for the determination of acidities outside of this range and for other classes of lubricants.

The high-temperature deposition test (HTDT) method is designed to evaluate the deposition and degradation characteristics of turbine lubricants when stressed under mixed-phase flow conditions found in certain parts of aviation gas turbine engines. This method is applicable to lubricants that form deposits in the range of 0.1 to 100 mg during the course of a test.

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.

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.

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 method is used for determining the compatibility of a candidate lubricant with specific reference lubricants. The reference lubricants to be used will typically be mandated by the owner of the product specification against which the candidate lubricant is being compared. This method is split into two procedures (Procedure A and Procedure B) with a summary of each procedure contained in Section 4.

The document is a recommended guide for evaluating new or replacement test methods. It considers applicability, suitability, accessibility, and return on effort. Particular emphasis should be placed on completing the “strategy definition” portion of this document (Stage 2), to capture all relevant process stages and complete in a recognizable order for any specific development project. The overall process should: 1 address the rationale behind testing; 2 result in a thorough review of whether a test is fit for purpose; 3 act as a pathway for vetting if a test should be added to AS5780. If, in any project, this process is not an exact fit, users should feel free to adjust, as necessary. The process provides the following stages:

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.

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.

The lubricant performance capability for aero propulsion drive systems is derived from the physical properties of the oil and the chemical attributes associated with the oil formulation. All 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. To assure performance and to provide needed information for engineering design, test methodologies for at least five oil properties or attributes are being addressed: (1) pressure-viscosity coefficient, (2) full-film traction coefficient, (3) scuffing resistance, (4) wear resistance, and (5) micropitting propensity. While viscosity versus temperature data are readily available, the above five properties or attributes must be measured under relevant conditions for aero propulsion hardware systems.

This test method provides procedures for exposing specimens of elastomer materials (AS 568-214 size O-rings) representative of those used in gas turbine engines to lubricants or reference fluids under defined time and temperature conditions. This test includes both suspended and compressed O-rings. Resultant changes in the O-ring’s physical properties (tensile strength, elongation, hardness, mass, volume, and compression set) are measured to determine the amount of deterioration of the elastomer.

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.

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.

An oil sample is placed into an open top glass vial which is then inserted into a stainless steel pressure vessel. The vessel is then sealed, pressurized, and placed into a heated aluminum block bath for 18 hours. At the end of the 18 hour time period, the vessel is removed from the heat source and allowed to cool to room temperature at which time the contents of the vial are filtered and the total sediment is reported as milligrams of sediment per 20 mL of oil.

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.

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 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 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.