A highly modified F-18B Hornet fighter being flown by NASA's Dryden Flight Research Center settles towards the runway at Edwards Air Force Base following another research flight. Known as the Systems Research Aircraft (SRA), the two-seat F-18 is currently engaged in a multi-year project to evaluate a variety of advanced control subsystems and sensors. Among the more than 20 experiments being researched in the joint NASA/DOD/industry program is the Electrical-Powered Actuation Design (EPAD), which is testing prototype aileron actuators which operate independently of the aircraft's hydraulic system. One experimental electrohydrostatic actuator (EHA) generates hydraulic force to move the aileron via a compact electric-driven hydraulic pump incorporated in the actuator itself. Another "smart" actuator uses actuator-mounted electronics while a third electro-mechanical actuator is electrically operated and moves the aileron mechanically. Such actuators could eliminate much of the need for complex central hydraulic systems on future aircraft, with signifigant savings in weight and cost. They are also being evaluated for use on the planned Reusable Launch Vehicle.
