On June 1, 2002, about 0700 eastern daylight time, a homebuilt Comp Air 7SL, N753KD, was substantially damaged during a landing rollout at Cross Keys Airport (17N), Cross Keys, New Jersey. The certificated private pilot, two pilot-rated passengers, and one additional passenger were not injured. Visual meteorological conditions prevailed at the time. No flight plan had been filed for the flight, from Old Mans Airport (7N7), Pedricktown, New Jersey. The personal flight was conducted under 14 CFR Part 91. The pilot reported that during the landing rollout on runway 27, the "tail wheel broke." It then jammed into the rudder and elevator, "which caused [us] to lose our steering and control of the airplane." One of the pilot-rated passengers stated that the "tail wheel broke and flipped up between the elevator, jamming the rudder and causing the aircraft to skid." The airplane subsequently swerved off the right side of the runway, and came to rest in a drainage ditch. According to a Federal Aviation Administration (FAA) inspector, the tailwheel spring fractured and jammed the rudder. The airplane veered off the runway, the main landing gear collapsed, and the fuselage and wings were damaged. Examination of the spring revealed previous damage, including beach marks and rust on the fracture surfaces.