Incident Details
The helicopter, which had been placed in flyable storage, was on a weekly flight to operate its various systems. After landing on soft terrain, the pilot started the takeoff. As the helicopter lifted off, it rolled over and the main rotor blades struck the surface. This impact caused the main rotor system and transmission to separate from the aircraft.
Investigation Findings
An examination of the helicopter revealed no preimpact failures. The terrain at the location consisted of mowed sod with black soil underneath, and the surface was soft. Investigators found two deep ruts at the site, along with additional ruts from the skids nearby. These ruts were consistent with the skids sinking into the soft ground.