Flight Alaska Cessna 206 accident

The solo commerical pilot departed on a CFR 135 on-demand cargo/U.S. mail flight en route to a remote coastal village. The flight did not reach the destination. A search and rescue satellite received an ELT signal, and the wreckage was located about 80 miles from the departure airport, along the airplane's intended flight path. A pilot who departed about 25 minutes before the accident airplane, also en route to the same coastal village, characterized the weather conditions along the route as "low visibility with light snow squalls moving through the area." He added that flat light conditions made it very difficult to discern any topographic features. Another pilot who was transiting through the area in the opposite direction, about the time of the accident, characterized the weather conditions as overcast with ceilings ranging between 1,000 and 1,300 feet. As he approached the site where the wreckage was eventually discovered, he encountered momentary visibility restrictions due to fog and light snow. He added that flat light conditions made it very difficult to discern any topographic features among the featureless, snow-covered terrain. The pilot stated that he changed his route in order to avoid worsening weather conditions. The accident airplane was equipped with an avionics package provided by the FAA's Capstone Program. The Capstone Program is a joint industry/FAA demonstration program that includes global positioning system (GPS) avionics, weather and traffic information provided through automatic dependent surveillance-broadcast (ADS-B), and terrain information depicted on a multifunction display (MFD) installed in the cockpit. Terrain depiction information, based on GPS data, is one of several visual display options available to the pilot on the MFD. Damage to the accident airplane's MFD precluded a determination of the visual display option selected at the time of the accident. At the time of the accident, position information from ADS-B equipment in the airplane was being provided to the Air Route Traffic Control Center (ARTCC). The recorded ARTCC data were reviewed to determine the flight track of the accident airplane. The radar-like track depicted the accident airplane's takeoff from the departure airport, on a heading of approximately 300 degrees. While en route, the airplane climbed to an altitude of about 1,800 feet msl. As the track continued in a northwesterly direction and approached the accident site, a gradual descent was noted. The radar-like track stopped approximately 1.8 miles east of the accident site, with a ground speed of approximately 108 knots. Examination of the accident site revealed physical evidence indicating the airplane impacted the ground on a southeasterly heading (directly opposite of the on-course heading for the intended flight) in a slight nose down attitude. No evidence of any pre-impact anomalies with the engine or airplane were noted.

Verbatim NTSB analysis and probable cause from the NTSB dataset