What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Upon arriving at the job site to begin aerial application the pilot noted an uncommanded increase in engine RPM accompanied by a loss of lift. He reduced collective in an attempt to preserve rotor RPM and initiated auto rotation. There was insufficient rotor energy and altitude (approximately 150 to 200 feet AGL) to cushion the landing. The helicopter struck the ground and suffered substantial damage. One main rotor blade severed the tail boom and the other rotor blade struck the ground causing substantial damage to both main rotor blades. The pilot shut the engine down after impacting the ground. The pilot was not injured and there was no other property damage. The NTSB, insurance company, and Hiller aircraft corporation have declined to teardown the engine and transmission assembly to determine the cause.
As the FAA filed it
UPON ARRIVING AT THE JOB SITE TO BEGIN AERIAL APPLICATION THE PILOT NOTED AN UNCOMMANDED INCREASE IN ENGINE RPM ACCOMPANIED BY A LOSS OF LIFT. HE REDUCED COLLECTIVE IN AN ATTEMPT TO PRESERVE ROTOR RPM AND INITIATED AUTO ROTATION. THERE WAS INSUFFICIENT ROTOR ENERGY AND ALTITUDE (APPROXIMATELY 150 TO 200 FEET AGL) TO CUSHION THE LANDING. THE HELICOPTER STRUCK THE GROUND AND SUFFERED SUBSTANTIAL DAMAGE. ONE MAIN ROTOR BLADE SEVERED THE TAIL BOOM AND THE OTHER ROTOR BLADE STRUCK THE GROUND CAUSING SUBSTANTIAL DAMAGE TO BOTH MAIN ROTOR BLADES. THE PILOT SHUT THE ENGINE DOWN AFTER IMPACTING THE GROUND. THE PILOT WAS NOT INJURED AND THERE WAS NO OTHER PROPERTY DAMAGE. THE NTSB, INSURANCE COMPANY, AND HILLER AIRCRAFT CORPORATION HAVE DECLINED TO TEARDOWN THE ENGINE AND TRANSMISSION ASSEMBLY TO DETERMINE THE CAUSE.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.
Other reports on N4033P · 2
Matched to the same aircraft by N-number and date.