SEA06FA115 · Cessna TU206G

The airplane flew into terrain while maneuvering after encountering weather. Before the first leg of the two-leg on-demand air taxi flight began, the pilot had checked the weather with the FSS for the entire route of flight. The specialist reported mountain obscuration and reduced visibility with rain and fog/overcast. The worst of the weather was reported for the second leg of the flight through the mountain pass with the fog/overcast reported as indefinite at 100 feet. After departure from the originating airport, the pilot requested an updated weather briefing. The weather report was similar and had not changed significantly. The flight landed at the first destination without incident. While on the ground, the pilot once again contacted the FSS to get an updated briefing for the final leg of the flight. The specialist reported that VFR flight was still not recommended and that there were AIRMETs for mountainous terrain obscured and occasional IFR conditions. An automated surface observing system (ASOS) is located at the mountain pass through which the flight was intending to fly. The ASOS at the time was reporting IFR with visibility 1/4 mile in fog, and ceiling broken at 100 feet, and overcast at 600 feet. The destination airport was reporting moderate to heavy showers which were slowly moving in. The specialist recommended to the pilot that he should wait at the airport as the forecast was showing an improving trend throughout the day. A witness traveling westbound on the interstate that runs east/west through the mountain pass, reported that she observed an aircraft traveling eastbound directly over the interstate. She estimated that the aircraft was just below the ceiling, which was a solid layer about 500 feet agl. She stated that from about 1 mile east to 1 mile west of the top of the pass, the clouds were directly on the road. As she descended lower in the valley, the cloud bases were no higher than about 500 feet agl. On site investigation of the wreckage indicated that the aircraft collided with several trees and subsequently the steeply rising terrain in an easterly direction on the south side of the interstate and about 150 feet above the roadway surface. At the approximate time of the accident, the ASOS located about 3 miles east of the accident site was reporting an indefinite ceiling at 100 feet, and a visibility of zero.

Verbatim NTSB analysis and probable cause from the NTSB dataset