Fatal Ultralight Aircraft Accident Near Jahnsfelde

Incident Overview and Flight Details On 13 September 2006, a factory-new Flight Design CTSW 2006 ultralight aircraft crashed near the village of Jahnsfelde, Germany. The aircraft, manufactured by Flight Design GmbH, was a single-engine, high-wing, shoulder-wing design with a fixed tricycle landing gear. It was powered by a Rotax 912 ULSFR engine. The aircraft was undergoing a factory test flight from the airfield at Eggersdorf to verify its technical condition prior to export delivery to France. The flight departed at 12:20 local time. After leaving the traffic pattern, the aircraft flew eastward toward the area between Heinersdorf, Marxdorf, and Jahnsfelde, where several maneuvers were performed. ## Accident Sequence and Investigation Findings A witness observed the aircraft enter a steep, inverted attitude shortly after crossing the B1 federal highway. The aircraft then performed three to four rolls before crashing into a wooded area west of Jahnsfelde at approximately 12:30 local time. The 37-year-old pilot, who held a Ukrainian-issued ultralight pilot license, was found severely injured in the wreckage and died in a hospital hours later. The aircraft was destroyed, and forest and field damage occurred. ## Technical and Meteorological Factors The aircraft was not equipped with a ballistic recovery system, as it was intended for the French market. The pilot was wearing a personal parachute but showed no signs of attempting to eject. Meteorological conditions at the time included winds of 15 knots, gusting to 25 knots, from 150 to 200 degrees, with clear skies and visibility exceeding 10 kilometers. Radar data indicated a ground speed of approximately 287 km/h in the final flight segment. ## Trim System Investigation Post-accident testing by Flight Design GmbH revealed that the trim system's preloaded spring could enter a blocked state. This condition could release suddenly, causing a significant nose-down trim adjustment. This effect was reproducible with a new spring under specific tension and trim settings but diminished after several repetitions. The accident aircraft's trim system could not be tested due to extensive damage. The manufacturer subsequently introduced a telescopic guide to prevent spring buckling and the associated snap-back effect.