SAE ARP5945A

The purpose of this Aerospace Recommended Practice (ARP) is to provide the sample selection criteria and endurance time test procedures for SAE Type I aircraft deicing/anti-icing fluids, required for the generation of endurance time data of acceptable quality for review by the SAE G-12 Holdover Time Committee. A significant body of previous research and testing has indicated that all Type I fluids formulated with conventional glycols, as defined in 3.1.1 of AMS1424, perform in a similar manner from an endurance time perspective. This applies to Type I deicing/anti-icing fluids formulated with propylene glycol, ethylene glycol, and diethylene glycol only. As a result, Type I deicing/anti-icing fluids containing these glycol bases no longer require testing for endurance times. The methods described in this ARP shall be employed, however, if endurance time testing of a conventional glycol-based Type I deicing/anti-icing fluid is desired or requested by a fluid manufacturer, operator or other organization. Fluids formulated with non-conventional glycol, as defined in 3.1.1 of AMS1424, and all non-glycol Type I deicing/anti-icing fluids, must be tested for endurance times using the methods described in this ARP (as appropriate). This document has been updated to reflect current practices for conducting endurance time tests with SAE Type I fluids. Notably, a requirement has been added to conduct tests on composite surfaces in addition to the traditional aluminum surfaces, test conditions have been updated to reflect changes made to the conditions encompassed by the holdover time guidelines (e.g., removal of the “Above 0 °C” temperature band). In addition, test protocols have been added for conducting endurance time tests in laboratory snow and natural frost. Also, further wording has been added to make clearer which SAE Type I fluids are required to undergo endurance time testing and which are not. Finally, editorial changes have been made to improve clarity.