What happened
A helicopter was engaged in a flight to transport a passenger to a remote location for the purpose of replacing batteries in a seismic recorder box. During the final stages of the flight, the pilot transitioned from a landing approach into a hover, maintaining a skid height of approximately 1 to 2 feet above the ground.
At this altitude, an empty canvas heli-bag situated on the ground was blown into the main rotor system. The contact caused the aircraft to develop severe vibrations. Following these vibrations, the main rotor system separated from the aircraft, resulting in a moderately hard landing upon impact with the ground. The passenger was not injured.
Findings
The operator noted that the accident could have been avoided if the heli-bag had been properly secured and if the aircraft had maintained a safe distance from both the bag and the equipment box on the ground.