Accident Details
On August 27, 2019, at about 1716 Pacific daylight time, a Bell 47G-4A helicopter, registration N6064H, was substantially damaged in an accident near North Las Vegas, Nevada. The pilot and a passenger were not injured. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.
Pilot and Passenger Actions
The pilot had purchased the helicopter in August 2018 and had flown it only twice before. During what would have been his third flight, while air taxiing at about 40 knots, the pilot observed that the engine was not generating enough power to keep the rotor speed in the green arc of the tachometer, so he terminated the flight. Witnesses informed the pilot that the engine was backfiring during the hover.
Seeking assistance, the pilot contacted an acquaintance who claimed to be a commercial pilot with 3,000 hours of helicopter flight experience, including 300 hours in Bell 47 helicopters. On the day of the accident, the pilot and the acquaintance cleaned and reinstalled the spark plugs. They then moved the helicopter to a helipad intending to run the engine and hover.
The pilot lifted the helicopter to a hover but found it difficult to control. He transferred the flight controls to the passenger, believing the passenger had more experience in the helicopter model. The passenger acknowledged that he had the flight controls. According to the pilot, the helicopter “rapidly tipped and tracked backwards to our right toward the parking lot.”
Federal Aviation Administration (FAA) inspectors interviewed the passenger, who admitted to making false statements about being a certificated pilot. FAA records confirmed that the passenger did not hold a pilot certificate.
Post-Accident Examination
Review of airport security video showed that shortly after takeoff to a hover, the helicopter drifted aft, banked left, and yawed to the right. The tail rotor impacted a fuel cart about the same time that the main rotor struck the ground. The helicopter then rolled onto its left side. The pilot and passenger exited through the right door with assistance from first responders.
Examination of the airframe revealed no preaccident mechanical malfunctions or failures that would have precluded normal operation. Examination of the engine disclosed that the No. 1 cylinder inner and outer intake valve springs were fractured and had collapsed, reducing the height of the springs.