On June 8, 2017, about 0900 central daylight time, a Piper PA-28-235 airplane, N3082T, struck a person while taxiing at a private airstrip near Harrisonville, Missouri. The private pilot was not injured, and a pilot-rated pedestrian was seriously 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 personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight originated from the Lawrence Smith Memorial Airport (KLRY), Harrisonville, Missouri, and the airplane landed on a private airstrip about 4 miles southwest of KLRY.According to information obtained by the responding Federal Aviation Administration inspector and sheriff's deputy, when the pilot taxied the airplane to park, he was taxiing past his friend (the pilot-rated pedestrian) who was using a camera to record the airplane. He felt a thump and could not see his friend, so he turned the airplane around and saw his friend laying on the ground. The friend was transported to the hospital. The airplane had damage to the left wingtip. An automated weather reporting facility near the accident site reported a clear sky with no restrictions to visibility. An NTSB Form 6120 was not submitted by the pilot.