Incident Overview
Following an oil change and oil screen inspection, the pilot reinstalled the oil screen and oil temperature sensing bulb. While securing the oil screen nut with safety wire, the pilot became distracted by incorrect safety wiring. This distraction led to the pilot failing to fully tighten the oil temperature sensing bulb nut.
Engine Failure and Ditching
On the first flight after the oil change, the oil temperature sensing bulb nut backed out of its attachment point, resulting in the complete loss of engine oil. The engine subsequently failed, and the pilot ditched the aircraft in the waters off Lopez Island.
Sequence of Events
The pilot had completed an oil change and checked the oil screen. During reassembly, the oil screen nut was installed but its safety wiring was done incorrectly. While focusing on this error, the pilot overlooked tightening the oil temperature sensing bulb nut properly. The inadequate tightening allowed the nut to loosen during flight, causing rapid oil loss and engine failure. The aircraft was then ditched in the water.
Investigation Findings
The investigation determined that the pilot's incorrect safety wiring of the oil screen nut created a distraction, which resulted in the failure to fully secure the oil temperature sensing bulb nut. This failure led to the loss of oil and subsequent engine failure.