Design & Development of the BA 609 Civil Tiltrotor Hydraulic System Architecture

When certified, the BA 609 will bring to civil aviation not only a giant step forward in VTOL aircraft speed and range, but also a leap forward in aircraft safety and reliability. The BA609 has been designed to meet the stringent transport safety standards for civil certification. Working in conjunction with the FAA, Bell and Agusta have also developed additional reliability requirements for fly-by-wire tiltrotor hydraulic system design. The design for the BA609 hydraulic system architecture is as specialized as the aircraft's rotor or wing design. Although the basic engineering principles used to design helicopter and airplane hydraulic systems are common, the operating requirements for a tiltrotor's hydraulic system design are unique. This paper presents an outline of the special hydraulic system design requirements for tiltrotor aircraft, as well as an overview of design and development of the BA609's unique hydraulic system architecture.