Supersonic Transport Fluid Evaluation Program

With the imminent development of the United States Mach 3 Supersonic Transport (SST), aircraft hydraulic fluid state-of-the-art must take another step forward to meet system performance requirements combined with high temperature environments.

This paper presents results of pumping tests conducted by Douglas Aircraft Company, Inc., on 18 different chemical types of proposed SST hydraulic fluids comprising 50 different fluid combinations. Pump and fluid performance data are presented for all 50 fluids evaluated. A general discussion of fluid properties versus performance is also provided.

Four specific fluid types are considered the best SST hydraulic fluid contenders. They are: chlorosilicone, mineral oil (super refined), perfluoroalkyl, and polyaryl.