On November 12, 2013, about 1200 central standard time, an unregistered Quad City Challenger I experimental light sport airplane, impacted terrain while returning for landing at the Winsted Municipal Airport (10D), Winsted, Minnesota. The pilot was not injured. The airplane sustained substantial damage to the left wing and fuselage. The airplane was owned and operated by the pilot as a personal flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The flight was originating at the time of the accident.
The pilot reported that the preflight inspection, run-up, and takeoff were normal. As he reduced engine power during the initial climb after takeoff, he felt a vibration that he associated with the engine or propeller. Reducing engine power further did not eliminate the vibration. He initially planned to attempt a downwind landing on the runway; however, the ultralight was too high and too fast. The pilot then decided to attempt a landing in a soybean field north of the runway. He initiated a left turn about 25 feet above ground level (agl) in order to line up with the field. However, the ultralight began to lose airspeed. About 8 feet agl, the ultralight inadvertently stalled and impacted the field.
A postaccident inspection did not reveal any anomalies related to the engine or flight control system, which would have precluded normal operation. Accordingly, the source of the reported vibration could not be isolated.
The pilot reported that he was operating the aircraft as an ultralight under 14 Code of Regulations Part 103. However, the accident aircraft was powered by a Rotax 503 engine, which according to the manufacturer, did not qualify to be operated as an ultralight. With a Rotax 503 engine installed, the aircraft exceeded the weight and maximum speed limitations specified for an ultralight. The accident airplane was required to be operated as an experimental light sport aircraft under 14 Code of Federal Regulations Part 91. The accident airplane had not been issued airworthiness or registration certificates. Incidentally, the Quad City Challenger I did qualify to be operated as an ultralight under Part 103 provided a smaller, lower power engine was installed.
The accident airplane had not been issued airworthiness or registration certificates by the Federal Aviation Administration (FAA). In addition, FAA inspectors were informed by the pilot that there were no maintenance records for the aircraft, nor were they supplied with any documentation of inspections or maintenance being accomplished.