The pilot stated that he listened to the weather report at the airport prior to landing, which reported a slight tailwind on runway 22 that was in use by other airplanes in the traffic pattern. The pilot chose to land on runway 22 with a tailwind rather than changing runways to favor a headwind. In a phone conversation, the pilot stated that he landed "within the first couple hundred feet" of the runway at about 85 knots, using full flaps. He said that during the landing roll he overran the runway, resulting in the airplane exiting the end of the runway and coming to rest on a 45 degree downslope. The pilot stated that he "underestimated" the length of the runway due to the fact that the airplane was almost at max gross weight and there was a slight tailwind. The airplane sustained substantial damage to the right aft main wing spar. According to the Avalon aviation weather report, at the time of the accident the wind was from 020 degrees at 5 knots. According to the Southwest U.S. Airport/Facility Directory, the accident runway 04/22 is 3,000 feet long. The first 2,000 feet of runway 22 is sloped up 1.8%, and the rest of the runway is level. At maximum gross weight in the weather conditions of the airport at the time of the accident, the airplane had a calculated ground roll of about 1,250 feet, with a total landing distance of about 2,500 feet. Taking into account the 5 knot tailwind and the 1.69% upslope, this airplane's final ground roll was calculated to be about 1,300 feet, and the total landing distance was about 2,650 feet.