Overview
At approximately 0530 Pacific Standard Time, a pilot departed from Ridge Field, Washington, on a flight to Hillsboro, Oregon. According to the pilot's instructor, the normal route for this trip would have involved proceeding on a southerly heading to Cornelius Pass, transiting the pass, and then continuing to Hillsboro. The helicopter crashed about 2.5 miles northwest of Cornelius Pass.
Weather Conditions
The 0548 PST weather observation at Hillsboro reported: 1,400 feet partially obscured, 3,600 feet overcast, visibility 7 miles, temperature 45°F, dew point 43°F, wind from 170 degrees at 10 knots gusting to 30 knots. The elevation at Hillsboro is 204 feet; the crash site was at approximately 900 feet. The pilot's instructor, who searched the area at 0200 PST, reported that the crash site was obscured by clouds, with strong turbulence, wind gusting from the south at 30 to 40 knots, and heavy rain.
Accident Sequence
Examination of the site revealed that the helicopter had collided with trees on a steep slope while in a turn.
Examination
No preimpact or mechanical malfunctions or failures were found that would have attributed to the accident.