What happened
The pilot received a weather briefing prior to departure that indicated visual flight rules operations were not recommended along the intended route. Despite this advisory, the aircraft departed Vancouver, Washington, and proceeded to Tigard, Oregon. The flight was observed leaving Tigard at approximately 1810 Pacific Daylight Time.
Subsequent reports from numerous witnesses indicated that around 1815, an aircraft was seen maneuvering at a low altitude near a highway. The plane then disappeared from view while flying toward rising terrain. Approximately five minutes later, at about 1820, residents located near the crest of the hills heard the sound of the aircraft crashing.
The investigation determined that the aircraft had struck the supporting guy wires for towers at a radio and television antenna farm. The impact took place at an altitude of approximately 250 feet above ground level. It was reported that the towers were not visible to the pilot due to the presence of clouds and fog.