ANC13LA074

The pilot was transporting sections of water hose to a remote site via a 100-ft-long external load line that was attached to the helicopter’s belly-mounted cargo hook. While the helicopter was hovering about 100 ft over the intended site and about 5 to 10 ft above trees while facing into a hill, the engine lost all power. The pilot then initiated an emergency hovering autorotation and turned the helicopter left in an attempt to face it downhill. Subsequently, the helicopter settled into trees, during which the main rotor blades impacted several of them, followed by it impacting terrain hard and rolling onto its right side, which resulted in substantial damage to the main rotor drive system, tailboom, and fuselage. During a postaccident examination, about 60 lbs of fuel were drained from the helicopter’s fuel cell; thus, fuel exhaustion did not cause the loss of power. During an engine test-run, the engine produced full-rated power at various power settings. Postaccident examination of the helicopter revealed no preaccident mechanical malfunctions or failures that would have precluded normal operation. Based on the available information, the reason for the loss of engine power could not be determined.

On August 5, 2013, about 1800 Alaska daylight time, a McDonnell Douglas/Hughes 500D helicopter, N134SH, was substantially damaged when it was involved in an accident near Delta Junction, Alaska. The pilot was not injured. The helicopter was being operated as a Title 14 Code of Federal Regulations Part 133 external load flight. The pilot was transporting sections of water hose to a remote site via a 100-ft-long external load line attached to the helicopter’s belly-mounted cargo hook. The pilot reported that while the helicopter was hovering about 100 ft over the intended site and about 5 to 10 ft above trees while facing into a hill, the engine lost all power. He then initiated an emergency hovering autorotation and turned the helicopter left in an attempt to face it downhill. Subsequently, the helicopter settled into trees, during which the main rotor blades struck several of them, followed by it impacting terrain hard and then rolling onto its right side, which resulted in substantial damage to the main rotor drive system, tailboom, and fuselage. During postaccident examination, about 60 lbs of fuel, 47 lbs of which were usable, were drained from the helicopter’s fuel cell. During an engine test-run, the engine produced full rated power at various power settings. During a subsequent test-run, the electric fuel pump operated within its operating specifications. Examination of the fuel pump revealed that the motor commutator and brushes exhibited wear. Postaccident examination of the helicopter revealed no preaccident mechanical malfunctions or failures that would have precluded normal operation.