What happened
Following an annual inspection completed the previous day, a pilot departed for a flight to a remote village located approximately 37 miles from the origin. At the time of departure, the aircraft was operating with fuel only in the left wing tank, as the right wing tank was empty. During the return leg of the trip, which took place within Class E airspace, visibility at the departure airport had dropped to 1.5 miles, necessitating the use of special VFR procedures under instrument meteorological conditions.
A distress signal was broadcast over the common traffic advisory frequency and monitored by a local flight service station. Search teams subsequently located the aircraft type on a flat, frozen, and snow-covered lagoon. The local weather at the crash site was characterized by fog and flat lighting. The wreckage was found in an inverted position with a nose-down attitude, and the engine had detached from the airframe. The debris path was oriented away from the higher terrain near the destination airport, which is situated on a peninsula.
Findings
An inspection of the engine showed no mechanical issues and confirmed the presence of fuel. However, investigators discovered that the internal support post of the vacuum pump had suffered a fracture; 70 percent of the break was attributed to fatigue, while the rest was caused by overstress. Although the aircraft was equipped with a standby vacuum system, this failure was noted. Additionally, a combination screwdriver with a shattered handle was found inside the left wing, though no interference with flight control cables was identified. The accident resulted in 0 fatalities and 0 injuries reported at the scene.