MD500 Main Rotor Drive System High Power High Reliability @ Low Cost Low Weight

Over the past few years, through completion of FAA and CRAD test programs, the MD500 series helicopters, particularly the 530 FF and 520 N NOTAR® versions, have been approved for higher gross weight and horsepower operations. Using independent research and development (IRAD) funds, McDonnell Douglas Helicopter Systems (MDHS) has designed an upgraded main rotor drive system for the MD500 series helicopter. The objective of the program was to design and produce a new main transmission and overrunning clutch with greater reliability at higher horsepower levels while maintaining design to cost constraints, to enhance mission performance, reduce operating costs, and reduce required spare parts inventory. This paper highlights the various design improvements and technological solutions used on the upgraded main rotor drive system as well as usage of State-of-the-Art technologies developed during the Advanced Rotorcraft Transmission (ART) programs.