Accident Summary
A helicopter conducting a rescue and recovery flight for the Alaska State Troopers crashed under challenging weather conditions. The aircraft, carrying a pilot and a state trooper, was en route to rescue the pilot of another aircraft when the accident occurred.
Flight Conditions
The helicopter departed in variable weather conditions. In the search area, snow was falling and winds were gusting between 70 and 90 mph. These severe conditions contributed to the difficulties encountered during the mission.
Accident Events
According to the pilot, the engine flamed out during a turn at approximately 1,000 feet above ground level (AGL). The pilot initiated an autorotation and transmitted a distress call. During the approach to a frozen river, the helicopter entered a total whiteout condition in fog and blowing snow at about 75 to 100 feet AGL. The pilot reported guessing at the altitude to apply collective pitch to stop the descent and experiencing vertigo during the final part of the descent. The aircraft impacted in a left, nose-down attitude and rolled over.
Survivability and Rescue
Following the crash, the occupants were unable to reach their survival gear in the wreckage. Weather conditions delayed their rescue, and the passenger died from hypothermia as a result of exposure.
Post-Accident Examination
No mechanical engine failure was found during the investigation. However, a coating of ice was discovered in the engine inlet. The helicopter was equipped with particle separators but had no snow deflectors installed.