What happened
On May 18, 2006, a private Mooney MO 20 J, registered F-GGGL, departed from Toulouse-Blagnac aerodrome bound for Tours Val-de-Loire. Shortly after takeoff, while the aircraft was stabilized at an altitude of 2,000 feet, the pilot noticed a slight fluctuation in engine RPM, followed by a complete loss of engine power.
Unable to restart the engine, the pilot identified a field surrounded by houses as a suitable landing site. During the approach, the pilot decided to land with the landing gear extended. However, as the aircraft made contact with the ground, the gear retracted. The aircraft subsequently slid on its forward fuselage before coming to a halt. There were no fatalities among the two occupants, though the aircraft sustained light damage.
The investigation
The investigation focused on the engine's failure and recent maintenance history. The aircraft had undergone a 100-hour periodic inspection in April 2006, which included the overhaul of the dual magneto and the replacement of capacitors. A few days prior to the accident, the pilot had noted an engine malfunction during a magneto check and sought repairs from a certified maintenance facility in Toulouse. During that repair, the magneto selector was replaced, and the dual magneto was subsequently exchanged for a standard unit, though no anomalies were detected at that time.
Post-accident examinations confirmed that the dual magneto was functioning normally. During the subsequent inspection of the aircraft, a mechanic identified a leak in the fuel flow meter.
Findings
- The engine failure was caused by the failure to detect a leak in the fuel flow meter.
- During engine testing, this leak caused engine misfires at low RPM and led to a total engine shutdown when maximum power was demanded.