The vintage biplanes were operating at a private airport that provided airshows and airplane rides to the public. The pilot of the departing airplane taxied for takeoff and was number two behind another airplane that was taxiing ahead of him. At the same time, the pilot of the landing airplane was in the traffic pattern, preparing for landing. Local procedures required landing airplanes to make a low approach to signal airplanes taking off that a landing was imminent; the procedure was implemented because some airplanes at the airport were not equipped with radios. Landing aircraft had the right-of-way over aircraft taking off. The pilot of the landing airplane reported that he performed the required low approach, completed the traffic pattern, and proceeded onto final approach for landing. At the same time, the pilot of the departing airplane taxied onto the runway for takeoff and did not see the low approach by the landing airplane or his subsequent pattern. The pilot of the landing airplane did not see the departing airplane on the runway and landed on top of the departing airplane before the departing airplane became airborne. Both airplanes sustained substantial damage, the two pilots had minor injuries, and two passengers were not injured. Although both airplanes were equipped with radios, neither pilot was making radio calls; instead, they relied on the established visual traffic separation procedures only. A review of the airport’s standard operating procedures revealed that they did not address the use of radios or encourage pilots to use them if equipped. Following the accident, the airport made several modifications to their local procedures including recommending that all pilots of aircraft equipped with radios use them while in the traffic pattern; and moving the holding area short of the runway to another location that afforded better visibility of the traffic pattern.