What happened
The pilot was attempting to land a tailwheel equipped airplane on a gravel bar located adjacent to a river. At the time of the event, the weather conditions included a 20-knot wind with gusts reaching 25 knots. While the initial touchdown on the gravel bar was uneventful, a sudden wind gust lifted the left wing. The pilot attempted to abort the landing; however, the aircraft ran off the end of the gravel bar and into the river, nosing down upon encountering the water. The pilot was not injured.
The investigation
The investigation focused on why the pilot could not counteract the wind gust. It was determined that the pilot was unable to fully displace the aileron to the left to compensate for the wind. This mechanical limitation was caused by the flap handle being in the flaps down position. Because of this configuration, the pilot's left leg was prevented from moving to the left, which subsequently blocked the control stick from achieving full left travel.