Engine Failure and Forced Landing After Propeller Governor Inoperative During Takeoff (N29632)

Overview

A pilot operated an aircraft with an inoperative propeller governor during takeoff. While cruising approximately 21 miles south of Ardmore, the pilot observed a loss of oil pressure and turned back toward Ardmore. The engine ceased operation four miles from the airport. The pilot declared an emergency and initiated a descent through cloud cover. The aircraft passed through some trees and subsequently landed in a pasture.

Sequence of Events

• The pilot began the flight with the propeller governor inoperative.
• During cruise at a location 21 miles south of Ardmore, oil pressure began to decrease.
• The pilot turned the aircraft toward Ardmore in response to the oil pressure loss.
• When the aircraft was four miles from the airport, the engine stopped.
• An emergency was declared by the pilot.
• The pilot descended through clouds.
• The aircraft encountered trees during the descent and then landed in a pasture.

Mechanical Findings

Examination of the engine revealed that the piston pin plugs had disintegrated. This disintegration introduced contamination into the oil system. Some of the metal debris caused the propeller governor drive shaft to separate. As a result, oil was depleted until oil pressure was lost, and the engine seized. The reason for the initial oil loss was not determined.