SEA05LA161 · Cessna A185F

The pilot reported that he had fueled the aircraft the day before with enough fuel for the two hour flight plus a one hour fuel reserve. The pilot reported that the en route portion of the flight was uneventful and a descent from 9,500 feet was initiated to 1,800 feet over the northeast side of Lake Washington, when the pilot had his first indication that something was wrong with the engine. The pilot stated that, "There were no sudden sounds; no choking or coughing of the engine. Rather it sounded as though someone had pulled the throttle all the way back - the normal sound (although I was at reduced power descending) just smoothly diminished to an idle sound over the course of about 1 second." The pilot made a turn to look for a landing spot and reported to air traffic that he was having problems. Not seeing a suitable landing spot, the pilot opted to head toward Sand Point, an area located along the west shoreline of the lake, in hopes to reach an open field. During the descent, the pilot switched the fuel selector from "both" to the left fuel tank and then to the right fuel tank. The engine did not start and the pilot focused his attention on the emergency landing. The aircraft was unable to reach Sand Point, therefore, the pilot maneuvered for a ditching parallel to the shoreline. The aircraft collided with the water, remaining upright. All three occupants were able to egress from the aircraft uninjured, before it sank. A nearby motorboat operator rescued the occupants within minutes of the accident. After the aircraft was recovered and the engine was dried out, the engine underwent an engine run. The engine started up the first time and ran at idle power for several minutes with no anomalies noted.

Verbatim NTSB analysis and probable cause from the NTSB dataset