Accident Overview
On the morning of the accident, a single-engine emergency medical services (EMS) helicopter was destroyed when it impacted trees in a national forest. The accident occurred at approximately 0532 eastern daylight time. Night visual meteorological conditions with mist and light fog prevailed at the accident site.
Flight Sequence
The flight crew was contacted around 0452 to assess their availability for a mission. The pilot conducted a weather check and accepted the mission about 0455, departing at approximately 0502. The helicopter arrived at the accident scene and landed on an interstate highway near a rest stop at about 0523. After about 10 minutes on the ground, the helicopter departed, heading toward the national forest north of the interstate.
Witness Observations
A witness reported that the helicopter made no abrupt maneuvers and that the engine "didn't sound like it was missing, sputtering, or any other kind of power loss." The witness observed the helicopter flying straight and level before it "pitched forward to go forward," then "flying level" as it descended into the trees. The witness noted that the helicopter's searchlight was on, and fog and mist were visible at treetop level.
Postaccident Examination
A postaccident inspection of the helicopter revealed no preexisting anomalies that could be associated with a pre-impact condition. Download of the engine's electronic control unit nonvolatile memory indicated that the engine was operating at 98 percent Ng when it struck the trees.
Mission Context
Three other EMS helicopter operators had turned down the mission, including one who attempted it but had to return because of fog conditions. However, the accident pilot was not informed that other pilots had declined the mission due to fog.
Findings
No probable cause was stated in the investigation source. The helicopter was destroyed, and the accident occurred under night visual meteorological conditions with mist and light fog.