High speed Civil transport (HSCT) hydraulic fluid development

GE Aircraft Engines required a new hydraulic fluid for engine nozzle actuation for the High-Speed Civil Transport (HSCT). Perfluoropolyalkylethers (PFPAEs), because of their nonflammability and high temperature stability, were selected early in the program. The authors have found two formulated PFPAE fluids for the application. The viscosity-temperature data, pressure-viscosity data, EHL (elastohydrodynamic lubrication) film forming ability, thermal stability data, antirust protection data and wear data were measured and the data used to select the candidates.