Rotors lose their bearings

Eurocopter has celebrated a milestone in the development of advanced rotor technology at its Donauwörth plant in Germany.

Following the first flight of a BK117 helicopter with an adaptive rotor system in September 2005, April 2006 saw the maiden flight of the newly developed five-blade Advanced Technology Rotor fitted on an EC145 test helicopter. The rotor is designed for four-ton class helicopters.

Development of advanced technology rotor systems began with the hingeless main rotor with composite blades (used by the BO105 and BK117 models), followed by the bearingless four-blade rotors of the EC135.

Key characteristics of the bearingless ATR are its compact and lightweight rotor hub and its modular components. These innovations are said to result in improved flight and a more comfortable ride compared with the EC145 rotor.

The five-blade rotor results in reduced vibration for both components and passengers. Its compact rotor hub improves flight characteristics. And fuel consumption and noise are lower due to the increased range over which the rotor speed can be varied.

'The rotor combines the most advanced design with aerodynamics aimed at achieving maximum performance with minimum noise,' said Dr Marius Bebesel, head of Eurocopter's vehicle technology and materials programme.