What happened
On June 10, 2018, a Cessna R172-K floatplane, registration I-DROV, was conducting a navigation flight from Biscarrosse Parentis to Béziers Vias. The aircraft was operated by the Aéro Club de Come and was carrying a pilot and one passenger.
After approximately 1 hour and 45 minutes of flight, while operating near the Carcassonne Salvaza aerodrome, the engine began to misfire. The pilot attempted various troubleshooting measures to restore power but was unable to do so. While attempting an emergency landing in a field, one of the aircraft's floats struck the treetops during the final approach, causing the aircraft to pitch forward and sustain heavy damage to the airframe.
The investigation
The BEA examined the wreckage located on a dirt path bordered by vegetation. Investigators noted that the damage to the aircraft was a direct result of the impact with the ground and trees. Notably, the propeller showed significant damage consistent with an engine that was not producing power at the moment of impact.
Upon inspecting the fuel system, investigators found that the left fuel tank was empty, while the right tank contained approximately 40 liters of fuel. The fuel selector was set to the "BOTH" position. The pilot, an experienced aviator with over 21,000 flight hours, reported that he had used the "BOTH" setting for most of the flight before switching to the left tank to balance the fuel levels. He also noted that the aircraft was flying at a low altitude of approximately 500 feet when the engine issues began.
Findings
- The investigation established that the engine failure was caused by fuel exhaustion in the left tank.
- The pilot had likely selected the left tank to balance the fuel levels, which led to the depletion of that tank.
- As the left tank emptied, it caused the fuel system to lose prime, resulting in a total loss of engine power.
- The low altitude of the aircraft at the time of the failure significantly limited the pilot's ability to execute the full emergency procedures outlined in the flight manual and restricted the options for selecting a suitable landing site.