Cat. 2 investigation report: simplified-format report, adapted to the circumstances of the occurrence and the investigation stakes.
On the day of the accident, the pilot travelled to the microlight strip at Flavacourt (Oise) in the afternoon. He talked to two other pilots who were planning a flight to Saint-André-de-l’Eure aerodrome (Eure). He decided to join them. He took off shortly after them, accompanied by a passenger who was also a microlight pilot. They all met up at Saint-André-de-l’Eure. From here, the pilot of the Sparviero and his passenger took off first, bound for Mureaux aerodrome (Yvelines). On the return leg, the microlight crashed in a field, in the commune of Jumeauville (Yvelines), 38 km from Saint‑André-de-l’Eure.
The blockage of the jet of one of the carburettors by a fly may have caused a desynchronization of the carburettors and led to a reduction in available power. However, this failure alone does not explain the loss of control.
The balance exceeded the aft balance limit described in the microlight’s user manual. This condition is conducive to a longitudinal instability and to a heightened sensitivity of the flight controls.
Excessive weight also tends to increase the stall speed.
If the reduction in speed that results from the decrease in power is not rapidly detected and corrected using an appropriate action, it may result in a loss of control.