Nonflammable hydraulic system development for aerospace

In 1975, the Air Force Laboratories were directed to evaluate ways to eliminate United States Air Force hydraulic fluid fires. This paper describes the approach selected: the development of a hydraulic fluid which would be totally nonflammable to any current or anticipated aircraft hydraulic fire ignition source. Flammability test criteria were established. Selection and optimisation of a suitable base stock, fluid characterisation and formulation efforts are presented.