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).