Event Narrative
After reaching cruising altitude of 8,500 feet, the pilot adjusted the engine fuel mixture to a lean setting. Several minutes later, the fuel mixture began to lean further without pilot input, and the engine subsequently lost power. Attempts to adjust the mixture using the mixture control handle were ineffective, as the handle had no effect on engine operation.
The flight initiated a descent for a forced landing at a nearby airport. During the turn onto final approach, the aircraft lacked sufficient altitude and airspeed to reach the runway. The landing was made on soft terrain short of the runway, causing the landing gear to collapse.
Post-Crash Examination
Inspection of the engine following the event found that the mixture control cable hold down bracket had broken near the engine. Additionally, a clamp that secured the cable to the engine mount was missing its rubber insert, which allowed the clamp to slide freely on the engine mount arm.
Maintenance Requirements
Manufacturer inspection requirements state that the mixture control cable should be inspected for security every 100 flight hours.