What happened
On August 3, 2002, a Wörner/NL-1000/Stu gas balloon departed from Düsseldorf-Eller at 04:01 for a passenger flight. The flight initially proceeded under expected conditions, but as the balloon approached Mönchengladbach, the pilot observed a dark wall of clouds. Due to deteriorating weather, the pilot decided to change course and attempt a landing west of the city area to avoid the approaching front.
During the landing approach, the balloon encountered a gust front associated with a convective line. This caused sudden turbulence and horizontal acceleration. The aircraft struck a pile of wood bark just before reaching the intended landing site, which caused the balloon to briefly ascend to approximately 8 meters. In an attempt to maintain control and prevent further ascent, the pilot utilized the parachute vent. This resulted in an increased rate of descent, leading to a heavy impact in a sandy pit approximately 70 meters after the initial obstacle contact. The basket tipped forward and slid for several meters before coming to a stop. The impact resulted in two serious and two minor injuries among the occupants.
The investigation
The BFU examined the meteorological conditions and the pilot's preparations. The pilot had utilized a balloon weather report and attempted to obtain additional information via telephone prior to departure. While the initial reports suggested light winds, the investigation established that a convective line moved through the region between 06:00 and 08:00, bringing significant wind shifts and gusty conditions. The investigation also confirmed that the Wörner/NL-1000/Stu was technically sound, with no mechanical defects found during the post-accident inspection.