On October 21, 2017, about 1113 mountain standard time, an American Aviation AA-1A airplane, N9239L, was substantially damaged when it was involved in an accident near Maricopa, Arizona. The pilot and passenger were seriously injured. The airplane was being operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot’s son reported that his father was returning to the departure airport when the accident occurred. A witness reported that the airplane “seemed slow and low” during the approach to land and that it then struck power lines. Subsequently, the airplane descended rapidly and impacted the runway, sustaining substantial damage to the right wing and fuselage. Several witnesses reported that the power lines were unmarked and were above a power line marked with orange guide balls. The pilot did not recall the accident. One of the witnesses reported seeing a power line wrapped around the landing gear. Examination of the airplane did not reveal evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation. Control continuity was established.