What happened
The aircraft was flying level when it collided with the side of Glacier Peak at an altitude of approximately 10,000 feet mean sea level. The flight was en route from Alderwood Manor to a private airstrip near Spokane, Washington.
Exact weather conditions at the accident site were not recorded. However, several mountain climbers located about two miles away at an elevation of 6,000 feet described similar conditions as sky obscured with visibility reduced to 50 feet in light to moderate wet snow. The temperature was reported as +38 degrees Fahrenheit with no wind.
A witness who had flown the route with the pilot several times noted that flights typically passed south of Glacier Peak at altitudes between 10,000 and 11,000 feet. The witness stated that the pilot used navigation aids along the route and would fly in clouds if weather conditions dictated. While the pilot did not normally communicate on the radio during flight in clouds, he always obtained a weather briefing before departing.
It remains unknown which navigation aids, if any, were used during this specific flight. There is no known record of communications between the aircraft and any radio facility.