AS350 N755AE accident near Pioche, Nevada

Probable cause

The pilot’s failure to maintain altitude from terrain and subsequent loss of helicopter control due to entanglement of the external load cable with the tail rotor.

NTSB analysis

The pilot landed the helicopter on a mountain ridge to survey a job site. The purpose of the accident flight was to reposition the helicopter from the ridgetop downhill to a fuel truck to refuel before beginning external load operations. A witness reported that he dropped the pilot and passenger at the helicopter before the accident flight and saw a cable that was laid out on the ground in front of the helicopter. The pilot stated to him that the cable was 70 feet long. The witness left the pilot and passenger at the helicopter and drove away; shortly thereafter, he received a phone call about smoke in the vicinity and learned that the helicopter had crashed.

Examination of the helicopter revealed that the long line was entangled with the tail rotor, which had separated from the helicopter. The tail cone/vertical fin assembly was found about 365 ft from the main wreckage and exhibited evidence of cable abrasion. Examination of the flight controls and engine, as well as review of recorded engine data, revealed no evidence of mechanical anomalies that would have precluded normal operation.

Based on the available information, it is likely that the pilot failed to achieve adequate clearance between the long line and terrain before descending downhill toward the fuel truck, which resulted in the helicopter’s long line, becoming entangled with the tail rotor, and a subsequent loss of helicopter control.

Text from the NTSB. Open the NTSB docket for WPR20LA244 for the full record.