THE PILOT-IN-COMMAND STATED HE WAS TAXIING WITH A STRONG CROSSWIND. HIS TAXI SPEED WAS A NORMAL SPEED AND HE WAS HOLDING THE CONTROL STICK IN A NEUTRAL POSITION. A GUST OF WIND LIFTED THE LEFT WING AND THE PILOT THEN MOVED THE CONTROL STICK TO THE LEFT AND ADDED POWER. THE AIRPLANE DEPARTED THE RUNWAY AND WENT OVER AN EMBANKMENT ON THE SOUTH SIDE OF THE RUNWAY.