On July 14, 2004, a Hughes 500D (registration C-GVHG) operated by Prism Helicopters Ltd was involved in an aviation accident near Iliamna, AK. Investigators recorded the probable cause as: The ground crew's failure to use proper procedures while securing a sling load to the helicopter, which resulted in foreign object damage to the helicopter's main rotor system while idling. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 3 related events involving the same aircraft type or operator are linked below.
A commercial helicopter sustained structural damage to its main rotor system when a rope was accidentally thrown into it during sling load preparation.
Incident Overview
A commercial helicopter pilot reported an incident in which the helicopter, while stationary and operating at flight-idle, sustained structural damage to its main rotor system. The pilot and two helpers were preparing a sling load at the time.
Sequence of Events
The helicopter was sitting on the ground with the engine running at flight-idle. The pilot was climbing into the helicopter and did not observe the actions of the helpers. According to the pilot's account, one helper standing near the cargo door threw a rope to another helper. The rope was inadvertently tossed into the main rotor system and became wrapped around the rotor head.
Damage
The pilot stated that the main rotor blades and the rotor head received structural damage as a result of the encounter with the rope.