What happened
The pilot performed preflight checks on the helicopter and found all systems normal. After starting the engine, the pilot transitioned the aircraft into a hover and taxied toward the airport fuel pumps. Upon reaching the pumps, the pilot reduced the engine speed to 1,800 rpm and engaged the friction on the cyclic and collective controls.
A passenger was seated on the left side of the aircraft. Before exiting the helicopter to use the fuel credit card system, the pilot instructed the passenger not to touch the flight controls. While the pilot was at the fueling station, a noise was heard, and the pilot observed the aircraft rolling onto its side. The impact with the ground caused the engine to stop.
The pilot instructed the passenger to turn off the master switch and assisted the passenger in exiting the aircraft. There were no injuries reported following the event.
Findings
The investigation revealed that the pilot attempted a hot refuel, which is a procedure where fueling occurs while the engine is running. The airport manager stated that the pilot had been previously notified multiple times that hot refueling was prohibited at this location. Furthermore, section 4.02 (a.1) of the airport operation instruction manual explicitly prohibits fueling or defueling any aircraft while engines are running or while the aircraft is being warmed by external heat.