On May 14, 2012, approximately 1330 central daylight time, a Piper PA-24-250 airplane, N7171P, was substantially damaged during a forced landing to a field near Shawnee, Oklahoma. The private pilot was not injured. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a ferry flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight originated from Sundance Airpark (KHSD), Oklahoma City, Oklahoma, approximately 1315, and was en route to Shawnee Regional Airport (KSNL), Shawnee, Oklahoma. On final approach, the pilot lowered the landing gear handle; however, he did not receive confirmation that the landing gear was down and locked. The pilot stated that "a lot of force" was required to conduct the manual gear override, but he was not able to get the handle up. Shortly thereafter, the engine lost power. The pilot performed a gear up, forced landing to a field. During the landing, the right wing was buckled and the firewall was wrinkled. According to the Federal Aviation Administration inspector who traveled to the scene, the mixture cable was bent and would not move. The routing of the mixture cable did not match assembly drawings. The mixture cable was found separated from its last clamp prior to the carburetor mixture control and the mixture control was found in the cutoff position. He also noted that several clamps normally used to route the mixture cable were not present. A grease fitting on the over center link for the nose landing gear was in line with the bend in the mixture cable. According to the pilot, the engine had just been removed and reinstalled for an engine overhaul.