The pilot reported that he was landing in variable, gusting wind conditions and that prior to initiating the landing flare, his approach airspeed was about 45 miles per hour. About 12 feet above the runway the airplane lost lift, dropped to runway, and landed hard He recalled that the airplane impacted the runway about 150 feet from the threshold, the left landing gear partially collapsed, the airplane veered left and exited the left side of the runway, impacted a drainage culvert and nosed over. The airplane sustained substantial damage to both wings, engine mounts, and the empennage. The pilot reported that during the flight there were no mechanical malfunctions or anomalies with any portion of the airplane that would have prevented normal flight operations. As a recommendation, the pilot wrote that for the conditions he should have approached at a higher airspeed and flared further down the runway.