Event Overview
A helicopter pilot reported that after landing to refuel, the aircraft's power was reduced to flight idle and a two-minute cool down was initiated before the engine would be shut off. Approximately one minute into the cool down, a fuel truck approached the helicopter from the rear and struck the main rotor blades.
Damage
The helicopter sustained substantial damage to the main rotor blades as a result of the collision.
Pilot Report
The pilot stated that there were no preaccident mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.