Advanced Two-Bladed Rotor Systems At Bell Helicopter Textron

The two-bladed rotor system, as it has been incorporated in all production Bell helicopters, is noted for its simplicity and reliability. To adapt this system to future needs, Bell Helicopter Textron (BHT) is actively pursuing two advanced concepts. The first is a bearingless two-bladed main rotor (BMR) system, and the second is a wide chord two-bladed rotor (WCR) with a midspan flapping hinge or flexure. Parallel investigations of both rotor systems are now being conducted at BHT with the possibility that the two concepts will be merged at some future date. This paper discusses the current status, possible advantages, known potential problem areas, and measured results obtained to date.