Primary finding
Probable cause
The pilot’s failure to maintain clearance from the electrical box while repositioning.
Investigator assessment
Analysis narrative
The pilot reported that he was repositioning the helicopter on the helipad to refuel. During the maneuver, the helicopter drifted aft and the tailrotor struck an electrical box. The helicopter lost tail rotor authority and landed hard on the skids. The tailrotor driveshaft, gearbox, and driveshaft sustained substantial damage. The operator reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operations.