Accident Sequence
A DRG helicopter was taking off from a helipad at dusk. As the helicopter climbed through approximately 75 feet above ground level, the engine lost power. The pilot initiated an autorotation toward a parking lot, which required collective pitch input to reach the intended landing area. While maneuvering over the parking lot, the helicopter struck an electrical wire and subsequently crashed.
Examination Findings
Post-accident examination of the engine revealed that the turbine spur adapter gearshaft had failed due to fatigue. Aluminum-rich metal debris was found blocking the oil delivery tube that supplies lubrication to the gearshaft. Additionally, the oil inlet screen filter was missing. There was evidence of overheating and excessive wear on the gearshaft splines.
Maintenance Context
The 100-hour inspection checklist for the engine required removal and inspection of the engine oil system filter. With the filter removed, direct access was available to the spur adapter gearshaft oil delivery tube and the oil tube connector assembly cup filter.