NTSB Identification: ANC12CA082
14 CFR Part 133: Rotorcraft Ext. Load
Accident occurred Tuesday, July 31, 2012 in Wainwright, AK
Probable Cause Approval Date: 12/19/2012
Aircraft: ROBINSON HELICOPTER COMPANY R44 II, registration: N74496
Injuries: 1 Minor.

NTSB investigators used data provided by various entities, including, but not limited to, the Federal Aviation Administration and/or the operator and did not travel in support of this investigation to prepare this aircraft accident report.

After landing at the airport, the pilot asked ground personnel to fuel the helicopter while he prepared a sling load for his next flight. The pilot said that while he was weighing the sling load cargo on a nearby scale, the ground crew finished fueling the helicopter. The pilot then signed the fuel delivery manifest for the 25.4 gallons of aviation fuel. Shortly thereafter, the pilot boarded the helicopter and started the engine. He said that after liftoff, he picked up the 775-pound sling load and then departed toward his destination. About 10 to 15 seconds after takeoff, the engine began to run rough and lose power, so the pilot elected to land, but while attempting to set the sling load on the ground, all engine power was lost. The low rotor warning horn sounded, the pilot entered a low-altitude emergency autorotation and attempted to cushion the landing, but the helicopter landed hard. The helicopter sustained substantial damage to the fuselage and tail rotor drive system.

A postaccident examination revealed that the reciprocating engine helicopter had been inadvertently serviced with Jet A turbine fuel. In a written statement, the ground personnel who fueled the helicopter stated that they thought they were fueling the helicopter with aviation gas, but they were using the same trailer that they used to fuel larger (turbine-powered) helicopters.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The failure of ground personnel to ensure the helicopter was serviced with the proper fuel. Contributing to the accident was the pilot's failure to monitor the fueling process.

Full narrative available

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