Accident to the Cessna 177 registered F-HKLA on 30/07/2023 off the coast of Fréjus

After a flight time of around 30 min, the aeroplane’s engine speed substantially decreased twice to the point that the instructor was no longer able to hold level flight. After the second decrease in engine speed accompanied by strong vibrations, the instructor was obliged to ditch the aeroplane as it was too far from the coast with respect to its lift-to-drag ratio, degraded by the headwind. In this area, the coastal environment did not offer immediate, usable and accessible land due to urbanization.

It was not possible to determine with certitude the cause of the loss of engine power during the flight. The engine damage after its immersion in salt water made it impossible to determine whether the aeroplane's maintenance and storage conditions could have influenced the engine's operation and performance.

However, after analysis of the hour meter values and the estimation of the real average fuel consumption, higher than that taken into account by the instructor, possibly linked to the condition of the engine, it cannot be excluded that the two reductions in engine power were the result of the fuel system unpriming after the quantity of usable fuel in the two tanks had been completely or nearly completely used.