Incident Overview
A pilot was delivering supplies from a mountain site to a river work site. On the tenth and final flight, wind caused the helicopter and external load combination to shift laterally. At that time, the load or line became entangled in a tree. The helicopter began moving in an arc and subsequently crashed into the river.
Pilot Statement
The pilot stated that he was unable to release the load, although he had previously checked the electrical and manual release mechanisms and they operated normally. He estimated the wind was from 050 degrees at 5 knots gusting to 7 knots. The elevation of the crash site was about 3100 feet.
Sequence of Events
According to the pilot, on the last flight, wind conditions led to a lateral shift of the helicopter with its external load. This caused the load line to become caught in a tree. The helicopter then moved in an arcing path before crashing into the river. The pilot had verified the load release system functioned properly prior to the flight.