On June 4, 2005, about 1415 eastern daylight time, an experimental Auster Mark 6, N3675, was substantially damaged while landing at Old Bridge Airport (3N6), Old Bridge, New Jersey. The certificated private pilot and passenger were not injured. Visual meteorological conditions prevailed for the flight that departed from Bayport Aerodrome, Bayport, New York. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot reported that the airplane landed on runway 6 at 3N6, a 3,594-foot-long, 50-foot-wide, asphalt runway. During the landing roll, the right tailwheel steering arm separated, which caused an uncontrollable right turn. The airplane departed the right side of the runway, struck trees, and came to rest upright. During the impact, the airplane sustained substantial damage to both wings and the rudder. The airplane was manufactured in 1947. Examination of the tailwheel steering arm at the Safety Board's Materials Laboratory revealed that the fracture was adjacent to an apparent weld. The fracture surface was consistent with overstress, with no evidence of fatigue or preexisting cracking. In addition, the bolt hole at the end of the steering arm was elongated, consistent with high loads.