Variable Pitch Fan - The Solution to Achieving High Propulsive Efficiency Turbofan Engines 2009-01-3103

Engine manufacturers recognize that either a variable pitch fan blade or a variable area fan nozzle can provide the necessary fan stall/flutter margin to take the next step in engine cycle improvement with enhanced propulsive efficiency and low noise level. The patented Rotating Composite Technologies, LLC variable pitch fan design uniquely offers the same or lower fan hub/tip radius ratio of conventional fixed pitch designs and, with its light weight composite fan blades integrated with an even smaller disk, offers weight savings as well. A variable fan nozzle conversely adds additional weight to the propulsion system and notably will complicate aircraft installation issues relative to competitive manufacturer's engines.