On July 28, 1999, at 1042 central daylight time, a Beech C-45H, N72409, piloted by a private pilot, sustained substantial damage after a loss of directional control on takeoff roll, on runway 27 (4,400 feet by 44 feet, dry asphalt), at the East Kansas City Airport, Grain Valley, Missouri. The personal flight was being conducted under the provisions of 14 CFR Part 91 and was not on a flight plan. The pilot, who was the sole occupant, reported no injuries. The flight was originating at the time of the accident and was en route to the Kansas City International Airport, Kansas City, Missouri. The aircraft departed the prepared runway surface and impacted a ditch adjacent to the runway. During a post accident examination, a Federal Aviation Administration inspector noted that the tailwheel was not in the locked position. No anomalies were found that could be associated with a preexisting condition.