NTSB Identification: CEN11LA305
14 CFR Part 91: General Aviation
Accident occurred Saturday, April 23, 2011 in Massillon, OH
Probable Cause Approval Date: 11/22/2011
Aircraft: D & D AIRCRAFT ROTORWAY EXEC, registration: N614S
Injuries: 1 Minor.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The pilot reported that during cruise flight the engine speed increased to a high rpm and power was no longer being transmitted to the rotor system. He initiated an autorotation to a sloping, plowed field that was soft due to recent rain. The tail struck the ground during the landing flare and the main rotor blades contacted the tailboom. Postaccident inspection of the helicopter revealed the inner race of the bearing on the secondary shaft, located above the transmission clutch, was worn into the shaft, which most likely caused the clutch to disengage. This prevented the engine power from being translated to the main rotor. The cause of the wear was undetermined, and the secondary shaft was designed by the pilot.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The excessive wear on the secondary shaft, from the inner bearing race, which resulted in the transmission clutch disengagement and a loss of power to the rotor system. Full narrative available
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