On July 23, 1999, at 1600 central daylight time, a Beech C23 airplane, N6712W, was substantially damaged during a hard landing at the Tulsa International Airport, Tulsa, Oklahoma. The airline transport rated pilot and his pilot-rated passenger were not injured. The airplane was registered to Tulsair Beechcraft Inc. of Tulsa and operated by the pilot. No flight plan was filed and visual meteorological conditions prevailed for the 14 Code of Federal Regulations Part 91 personal cross-country flight, which originated from Wichita, Kansas, approximately 1500. According to the pilot, he was demonstrating a "power off landing when out of normal approach position." On final approach to runway 18R, "all appeared normal." The "airspeed was 60 kts," and the rate of descent was "approximately 500 feet/min." During the landing flare, the pilot noticed that his "aiming point" was "moving in the wrong direction." He "immediately tried to add power and as [he] was doing this [he] arrived at the ground - 3 pointed the aircraft, which resulted in damage." The pilot stated that runway 18R "has a large drop from about 50 percent of the length to the north." He further stated that he thought "the gradual loss of headwind when [he] descended below the crest of the runway, and the resultant loss of translational lift, allowed an increase in descent rate that went undetected until the flare." An FAA inspector examined the airplane and reported that the right main and nose landing gear assemblies were separated, the firewall was buckled, and the left wing's forward spar was damaged.