What happened
On July 19, 1961, a Miles Messenger, registration HB-EEC, was conducting a private pleasure flight from Geneva, Switzerland, to Le Mans, France. The aircraft was carrying the pilot and two passengers at the time of the incident. While flying near Bourges, France, the aircraft suffered a sudden engine failure. The pilot was forced to perform an emergency landing in the vicinity of Bourges. The landing was completed successfully at approximately 10:45 local time, and the aircraft sustained no significant damage beyond the engine failure.
The investigation
The investigation, which incorporated findings from the French civil aviation inspectorate and supplementary research conducted in Switzerland, focused on the mechanical cause of the power loss. Investigators examined the engine, a Cirrus Major 3, to determine why the propulsion system failed during flight.
Findings
The investigation established that the engine failure was caused by the failure of a connecting rod in the second cylinder. Specifically, the rod broke due to metal fatigue, which subsequently caused the component to penetrate the engine crankcase.