Accident Details
A dual instructional flight experienced an engine malfunction shortly after transitioning from climb to cruise. The certified flight instructor (CFI) reported that the engine began to slow down and experienced excessive vibration with decreasing RPM. The CFI took control of the aircraft and initiated a return to the departure airport. After descending from 3,500 to 700 feet above ground level, the engine was shut down.
During the turn to final approach, the CFI realized the aircraft would land short of the runway. The aircraft was landed in an open field, but during the rollout, it collided with trees.
Engine Failure
Post-accident examination revealed that the oil cooler's inlet oil line had failed during the transition from climb to cruise flight. The failure resulted in a loss of the engine's oil supply, leading to the subsequent engine failure.
The aircraft's oil lines were found to be the original equipment. The aircraft service manual specifies that oil lines should be replaced as required, but no later than every 1,000 hours of operation. The aircraft logbook indicated that five annual inspections and one 100-hour inspection had been completed since the aircraft accumulated 1,000 operational hours, but the oil lines had not been replaced according to the service manual schedule.
The forced landing was necessitated by the loss of engine power, and the aircraft struck trees during the ground roll after landing in the field.