Accident Overview
A helicopter crashed during a flight that was the pilot-rated student's first instructional flight in the aircraft. The helicopter had been recently rebuilt and was purchased by the student three days before the accident. About five minutes after takeoff, witnesses reported hearing a loud bang and observed the helicopter falling to the ground.
Impact and Wreckage
The helicopter impacted terrain in an approximately level attitude and came to rest upright. There was no postcrash fire. All major components were accounted for and recovered before being moved to a secured storage facility.
In-Flight Component Separation
Both doors separated from the helicopter during flight. The right door was recovered intact and undamaged. The left door was found in multiple fragmented pieces, including the door handle, frame, and latching mechanism.
Tail Rotor Blades
The two tail rotor blades were located 500 to 600 feet from the main impact point. One of the blades had two large impact areas near the tip of the leading edge. One impact area was rounded, while the other was broader and flat.
Paint Transfer Evidence
Examination of paint transfers revealed that material on the leading edge of a main rotor blade piece and on the door latching mechanism were transferred paint from the tailboom. Additionally, yellow paint on the main rotor blade was similar to paint from the tail rotor blade, likely from the same source.
Door Pins and Sequence of Events
The sequence of events before the accident flight, along with physical evidence, indicated that the door pins were not installed prior to the flight.
Main Rotor Strike
Physical evidence consistent with the main rotor diverging from its normal plane of rotation and striking the left windscreen was observed. A black transfer material measuring 24 inches by 5 inches was found on the upper left outboard area of the left windscreen. The initiating event that produced the main rotor divergence could not be determined.