Cessna 150 F-OGVK Accident at Saint-François Aerodrome

Incident Overview and Immediate Sequence of Events On 30 January 2012 at 11:15 local time, a Cessna 150 registered F-OGVK, operated by a flight club, departed from runway 11 at Saint-François Aerodrome (971) for an instructional flight. The aircraft was carrying a student pilot and an instructor. During the initial climb at approximately 300 feet, the instructor observed a decrease in engine RPM followed by fluctuations. The instructor took control of the aircraft and, determining that environmental conditions did not permit a landing in the runway axis, initiated a right turn to enter a suitable traffic pattern. ## Emergency Landing and Impact During the downwind leg, the engine RPM decreased again, prompting the instructor to attempt an emergency landing against the direction of the runway (contre QFU). The aircraft touched down in the middle of the runway. Despite maximum braking action by the instructor, the aircraft exited the runway longitudinally. In the grassy area, the aircraft crossed a ditch and overturned onto its back. The student pilot sustained minor injuries, and the aircraft was heavily damaged. ## Technical Findings and Maintenance History Technical examinations of the engine revealed anomalies in the ignition circuit. Specifically, the magneto cables showed unsatisfactory appearance and continuity tests, and the spark plugs exhibited incorrect operation and abnormal wear of their central electrodes (ovalization). The engine had approximately 1,900 hours of operation since the last major overhaul. A 100-hour inspection had been performed six days prior to the event, with the report noting that spark plugs and magnetos were inspected, no anomalies were found, and engine operation was verified during a ground run. ## Environmental and Operational Context The runway was a paved surface measuring 600 by 20 meters. The ditch where the aircraft overturned was located 83 meters from the runway threshold, outside the runway strip designed to mitigate damage in the event of a runway excursion. The instructor had approximately 3,870 hours of flight experience, including about 3,500 hours on type. A weather observation from the nearby Raizet Aerodrome (971), located approximately 15 nautical miles away, reported a wind from 080 degrees at 9 knots at 11:00. The investigation did not determine whether the instructor had performed pre-flight engine tests.