On April 5, 2018, about 1600 central daylight time, a Quicksilver GT400 ultralight airplane, N2433Z, was substantially damaged when it was involved in an accident at Maxwell Airport (3NC7), Maxwell, Iowa. The pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The pilot reported that he had just purchased the ultralight airplane and that he had not received a preflight weather briefing. The airplane’s previous owner reported that, earlier on the day of the accident, he completed a demonstration flight for the pilot in the airplane with “no issues.” He advised the pilot to use 10° of flaps for takeoff for improved performance; however, the previous owner saw the airplane take off without the flaps extended. After takeoff, he saw a wind gust push the airplane into a tree. The pilot reported he had no recollection of the accident. The pilot reported having flown only 3.5 hours in the previous 20 years in a Cessna or Beechcraft airplane and that did not hold a pilot certificate. The pilot indicated he thought the airplane was operated under 14 CFR Part 103; therefore, he believed that he did not require a pilot certificate. When asked by the previous owner if the he was a pilot, the noncertificated pilot said, “yes”. Examination of the airplane revealed that both wings and the fuselage had sustained substantial damage. Flight control continuity was established, and propeller damage was found that was consistent with the engine producing power at the time of impact. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.