Preflight Planning and Weather Briefing
An instrument-rated pilot received a preflight weather briefing from an official source. The briefer advised that visual flight rules (VFR) flight was not recommended and provided several pilot reports indicating overcast conditions and icing in clouds between 9,000 and 13,000 feet along the intended route. The pilot stated that he had already heard the hazardous weather advisories via the transcribed weather recording. Before departure, the pilot informed relatives that he planned to navigate under VFR due to forecast icing in clouds and intended to remain low to circumnavigate areas of weather.
Flight Path and Radar Data
In the hour following takeoff, radar data depicted the aircraft turning and circling as it climbed generally on course, eventually reaching 13,700 feet mean sea level (msl) in the vicinity of the accident location. The Safety Board Meteorologist determined that, at that position and altitude, the aircraft would likely have been within clouds and in conditions favorable for supercooled large droplets (SLD), producing a moderate to severe icing environment. Radar data showed the aircraft maneuvering near the accident site, descending from 13,700 to 11,100 feet over seven minutes, then continuing in a left-hand turn from 11,100 to 4,900 feet, where radar contact was lost 3.4 minutes later.
Accident Site and Conditions
The wreckage distribution indicated that the aircraft was in straight and level flight at the moment of impact with a mountainside. Area residents reported that the mountains were obscured by low clouds with poor visibility and periods of intense rain. The pilot was equipped with a nasal cannula oxygen dispensing device, which was found at the scene.
Pilot Equipment
A nasal cannula oxygen dispensing device was worn by the pilot, as indicated by its presence at the accident site.