Application of MIL-C-87252 in F-22 Liquid Cooling System

The purpose of this paper is to document the application to date, of Synthetic Dielectric Coolant Fluid, MIL-C-87252, in the liquid cooling system of the F-22 Advanced Tactical Fighter Environmental Control System / Thermal Management System (ECS/TMS). This fluid consists of a filtered polyalphaolefin (PAO) base stock that is blended with certain anti-oxidant additives. This paper describes the ECS/TMS liquid cooling system, discusses the rationale for choosing MIL-C-87252, and the lessons learned to date regarding the practical application of this fluid in the F-22. The topics discussed are potentially applicable to all liquid cooling systems.