What happened
During a scheduled local training mission conducted over the waters of Washington State, a seaplane was performing maneuvers before attempting to land on Lake Washington. As the aircraft approached the surface of the lake, it capsized and subsequently submerged.
There were three fatalities resulting from the accident, as all members of the crew perished in the sinking.
Findings
Investigations into the incident revealed that the aircraft's landing gear had not been retracted before the water landing. The failure to raise the landing gear prior to touchdown caused the plane to overturn during the landing phase.