On April 30, 2025, about 1950 central daylight time, a Cessna 180F airplane, N2135Z, sustained substantial damage when it was involved in an accident at the Halliburton Field Airport (DUC), Duncan, Oklahoma. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The pilot reported that the accident occurred while landing the tailwheel-equipped airplane on runway 17. The reported surface wind was from the west-southwest at 6-7 knots. The pilot reported that the airplane drifted right of the runway centerline during landing rollout, but his left rudder input did not correct for the right drift and the airplane departed off the right side of the runway. The airplane’s main landing gear sunk into soft turf which resulted in the airplane to nose over. The pilot and his passenger egressed from the airplane without injury. The airplane sustained substantial damage to the vertical stabilizer, rudder, and both wings. A postaccident examination of the airplane’s rudder control system revealed that the left rudder cable was fractured. The fractured rudder cable and an associated pulley were removed from the airplane and shipped to the National Transportation Safety Board’s materials laboratory for additional examination and testing.