What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Pilot reported loss of control of helicopter when control rotor tube assembly separated from helicopter. Helicopter fell through electrical power lines before impacting terrain causing substantial damage. Pilot and one passenger sustained minor injuries. Second passenger did not sustain any injuries. Preliminary inspection of failed part, Hiller part number 36124, indicated that a crack formed at the inboard attachment bolt hole and eventually continued along the circumference of the part before the outer portion of part (cuff) separated from the helicopter. Failed control rotor assemblyhas been sent to the NTSB for metallurgical analysis.
As the FAA filed it
(-23) PILOT REPORTED LOSS OF CONTROL OF HELICOPTER WHEN CONTROL ROTOR TUBE ASSEMBLY SEPARATED FROM HELICOPTER. HELICOPTER FELL THROUGH ELECTRICAL POWER LINES BEFORE IMPACTING TERRAIN CAUSING SUBSTANTIAL DAMAGE. PILOT AND ONE PASSENGER SUSTAINED MINOR INJURIES. SECOND PASSENGER DID NOT SUSTAIN ANY INJURIES. PRELIMINARY INSPECTION OF FAILED PART, HILLER PART NUMBER 36124, INDICATED THAT A CRACK FORMED AT THE INBOARD ATTACHMENT BOLT HOLE AND EVENTUALLY CONTINUED ALONG THE CIRCUMFERENCE OF THE PART BEFORE THE OUTER PORTION OF PART (CUFF) SEPARATED FROM THE HELICOPTER. FAILED CONTROL ROTOR ASSEMBLYHAS BEEN SENT TO THE NTSB FOR METALLURGICAL ANALYSIS.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.