Procedure for Thermal Aging Test for Polyol Ester Gas Turbine Engine Lubricants
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.
The Thermal Aging Test was initally developed by Turbomeca to predict the performance of polyol ester lubricants in helicopter gas turbine engines. The method is designed to evaluate the changes in the chemical and physical properties of gas turbine engine lubricants subjected to elevated temperatures in the presence of air. The results are primarily applicable to lower-oil-consumption gas turbine engines which do not experince high levels of top-off oil. The test has now been documented for the lubricants industry because the results of the procedure are required by AS5780. This document describes the required apparatus and provides a detailed procedure for obtaining the required results.