On May 14, 1997, a Hiller UH-12E (registration N7082D) was involved in an aviation accident near Truckee, CA. Investigators recorded the probable cause as: A loss of engine power for undetermined reasons. A factor in the accident was the unsuccessful attempt to release the long line from the belly hook after it became entangled in a tree. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter on a mission to move a 200-foot long line experienced an engine sound change after takeoff. While turning back for an emergency landing, the line entangled in a tree, resulting in impact with the ground.
Accident Details
The pilot reported that the helicopter was being used to relocate a 200-foot long line to a new clearing area. After departing from a dirt strip, the pilot heard a change in the engine sound. He decided to turn back for an emergency landing and attempted to release the long line. However, the line became entangled around a tree, causing the helicopter to impact the ground.
Examination
Federal Aviation Administration (FAA) inspectors examined both the helicopter and the long line. They were unable to determine at what point the line became entangled in the tree—whether during takeoff or upon the return for landing. Examination of the engine revealed continuity throughout, with no preexisting malfunctions noted.
Probable Cause
No probable cause was determined by the investigation.