NTSB Factual Report

On July 31, 2017, about 1300 Pacific daylight time, a Cessna 172S, N957TA, was substantially damaged following a ditching about 5 nautical miles northwest of the Seattle-Tacoma International Airport (SEA), Seattle, Washington. The airplane was registered to S & G Sky LLC and operated by the pilot as a 14 Code of Federal Regulations Part 91 instructional flight. The certified flight instructor (CFI)and the student receiving instruction were not injured. Visual meteorological conditions prevailed and a flight plan was not filed. The local flight departed the Boeing Field/King County International Airport (BFI), Seattle, Washington, about 1300.

In a telephone conversation with the National Transportation Safety Board investigator-in-charge, the CFI reported that upon completion of air work with the student and while returning to BFI, he observed a drop in oil pressure, followed by a partial loss of engine power, and eventually a total power failure. With insufficient altitude to make it to BFI, the CFI elected to ditch the airplane in the Puget Sound, about 50 yards from the nearest shoreline. Both the CFI and student egressed the airplane and swam to shore. Except for the top of the rudder and vertical stabilizer, the airplane came to rest upright and submerged in shallow waters.

The airplane was recovered from the accident site to a secured location for further examination.