On March 15, 1985, a Hughes 369HS (registration N1040Z) operated by Kcmo Radio was involved in an aviation accident near Princeton, MO. Investigators recorded the probable cause as: The pilot's failure to maintain clearance from power lines during the approach, which resulted in a collision with the tail rotor. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter collided with power lines while approaching an open field, causing severe vibration and loss of control before impacting the ground.
What happened
The accident occurred when a helicopter's tail rotor struck power lines during an approach to an open field. According to the pilot, as the aircraft descended onto the field, it began to vibrate severely. This vibration caused the pilot to lose control of the helicopter. The aircraft then executed two 360-degree revolutions, with the nose swinging to the right, before contacting the ground and coming to rest on its left side.
The investigation
The investigation focused on the mechanical interaction between the helicopter and the power lines. The primary finding was the physical contact between the tail rotor and the overhead wires during the descent phase of the flight.
Probable cause
The pilot's failure to maintain clearance from power lines during the approach, which resulted in a collision with the tail rotor.