At the end of the en-route phase, the pilot thought that it was not certain that he would be able to land at his destination due to the meteorological conditions. He therefore decided to divert to Montmorillon microlight strip which he had flown to on several occasions during his microlight training. The pilot joined a left-hand circuit for runway 35 in order to align the aeroplane on very short final, with the flaps in the landing configuration. The flight path was controlled until the aeroplane reached the runway threshold. The pilot flared on crossing the runway threshold and then applied full power for a reason that the investigation was not able to determine. The pilot then lost control of his aircraft. The presence of a right crosswind component accompanied by probable gusts, combined with the engine effects may have made the control of this flight phase more difficult.