What happened
On August 25, 2008, a pilot operating a B&F Technik FK 14 Polaris ultralight aircraft began a flight from Speyer toward Mainz-Finthen. Following the Rhine River northward, the pilot eventually turned northeast near Cologne. As weather conditions deteriorated due to an approaching occlusion, the pilot decided to turn back toward the Rhine.
During the flight, the aircraft entered a region of multi-layered clouds. Radar and GPS data indicated that between 12:18 and 12:28, the aircraft performed several turns and full circles. The pilot reported that upon entering the clouds, he lost control of the aircraft and subsequently activated the onboard emergency parachute system. At approximately 12:24, a commercial aircraft on approach to Cologne-Bonn Airport received a TCAS alert, and air traffic control notified the crew of an unidentified radar target within the control zone. Shortly after 12:29, witnesses observed the ultralight aircraft descending into a residential garden in the Flittard district of Cologne, suspended by its parachute.
The investigation
The BFU examined radar data, GPS logs, and meteorological records from the German Meteorological Service (DWD). The investigation reviewed the pilot's pre-flight weather preparations and analyzed the aircraft's flight path and the impact site. The investigation also looked into the weather development in the Cologne/Bonn area, noting the presence of an occlusion and varying cloud layers.
Findings
- The pilot attempted to gain altitude while flying within multi-layered clouds.
- The pilot lost orientation and control of the aircraft while attempting to climb through the cloud layers.
- The emergency parachute system was activated while the aircraft was still within the clouds.
- The aircraft struck a residential garden at a 30-degree nose-down angle, causing heavy damage to the airframe and property damage to the ground.