On August 5, 2016, about 1800 central daylight time, a Piper PA-25-235 airplane, N6542Z, impacted terrain near Kingsley Airfield (MO9), Miller, Missouri. The commercial rated pilot was not injured and the airplane was substantially damaged. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan.According to a statement provided to the Federal Aviation Administration (FAA) by the pilot, he was test-flying N6542Z that had just been through "a complete restoration." After takeoff, about 10 minutes into the flight, the left aileron cable separated from the control stick. The pilot added that he was able to turn the airplane back towards the runway. As the airplane slowed, it become more and more difficult to control the airplane. The right wing then impacted a corn field about 300 ft from the runway. An examination of the airplane by FAA inspectors found that the swage fitting on the aileron control cable was improperly swaged, allowing the aileron to come loose from a control turnbuckle. The aileron cable was replaced and rigged during major maintenance and the airplane completed its annual inspection on February 9, 2016. The accident flight was the first flight since that restoration/annual inspection.