What happened
On March 1, 2011, a Cessna 150 K departed Trier-Föhren for a flight to Bonn-Hangelar to deliver the aircraft to a maintenance facility. The pilot initially flew under the cloud layer without difficulty. However, as the aircraft approached the Nürburgring area, the cloud cover thickened, prompting the pilot to climb to fly "on top" of the clouds.
As the flight progressed, the cloud layer continued to thicken. To avoid entering controlled airspace (Class C) near Cologne-Bonn, the pilot decided to descend back below the clouds. During this descent, the pilot utilized a gap in the cloud cover, but upon emerging, found the aircraft flying at an altitude that left insufficient clearance from the high terrain of the Eifel region. Due to the limited performance of the Cessuna 150 K, the pilot was unable to climb back through the cloud gap to clear the obstacles. To avoid an imminent collision with the clouds, the pilot executed an emergency landing in a forest.
The aircraft struck treetops and crashed into a dense deciduous forest. The impact resulted in the destruction of the aircraft, including the separation of the right wing and the nose gear. The pilot sustained one minor injury and was able to contact emergency services via mobile phone.
The investigation
The BFU investigation examined the flight path, meteorological conditions, and the aircraft's performance. Investigators reconstructed the flight using radar data and analyzed the weather reports from the German Meteorological Service (DWD) and GAFOR. The investigation also looked into the pilot's decision-making process and the aircraft's equipment, noting that an Emergency Locator Transmitter (ELT) was not on board at the time of the accident, as it had been left at the departure airfield.
Findings
- The pilot transitioned from flying above the clouds to flying below them to maintain VFR conditions and avoid controlled airspace.
- The flight path through the Eifel region led the aircraft into high terrain that was partially obscured by clouds.
- The pilot had not adequately cross-referenced the terrain elevations in the aeronautical charts with the chosen flight altitude.
- The pilot entered a "weather trap" by descending into high terrain while the cloud ceiling was lowering.
- The pilot's decision to descend was influenced by the fact that the flight was a repositioning flight and a ground contact was awaiting him at the destination.