Background
The aircraft experienced a left engine and propeller feathering due to low oil pressure, prompting the pilot to divert to an alternate airport. The last annual inspection was dated March 5, 1984, and a 100-hour inspection of the airframe only was performed 2.3 flight hours before the accident. The engine logbooks were not located.
Event Summary
During the final approach with the landing gear extended and the aircraft in a landing configuration, the pilot applied power, but the right engine provided only about 40% of the expected torque. Attempts to correct the problem were unsuccessful. The pilot then retracted the landing gear and ditched the aircraft.
Findings
Post-accident examination of the left engine nacelle revealed oil leakage from an unknown source, which had depleted the oil supply. The right engine's condition and power levers were operationally checked. When moved, the linkage at the propeller governor did not move; the fuel control concentric shaft control linkage assembly was described as 'stiff.' No determination could be made as to why the propeller governor did not move when the condition lever was moved. The right engine was subsequently removed for an engine run and operated normally. The propeller governor and propeller pitch control were also tested and operated normally.