Flight Details
A certificated commercial pilot and four passengers departed a remote airport on a scheduled air taxi flight under visual flight rules (VFR) during dark night conditions over snow-covered terrain. The pilot reported obtaining weather information from his home computer, pilot reports, and personal observations.
Flight Path and Encounter
After takeoff, the pilot deviated around a small mountain range between the departure and destination airports. He stated that the deviation was planned to maintain a minimum of 1,000 feet above ground and to stay below icing conditions. During the flight, the aircraft encountered a snow shower. The pilot said he had no outside visual references for navigation and relied on the airplane's directional gyro for course information. He reported that the gyro rotated to the left, placing the aircraft near a mountain.
Collision
The airplane collided with snow-covered terrain at an elevation of about 900 feet mean sea level (msl). Passengers reported that they could not see the ground and were unaware of any problem until the aircraft came to an abrupt stop.
Weather Information
An area forecast included an AIRMET for mountain obscuration, light isolated moderate rime icing in clouds, and marginal VFR ceilings in snow and mist.