What happened
On February 26, 2000, a Reims Aviation F152, registration HB-CGT, departed Zurich for a private flight to Bern. The flight was originally intended to head east toward Lake Constance, but the pilot altered the route to Bern after reconsidering the weather conditions. During the flight, the aircraft maintained an altitude of approximately 2,000 feet while passing over the Katzensee and Gasometer Schlieren areas.
As the flight progressed, the aircraft encountered heavy fog, transitioning from visual conditions to instrument meteorological conditions (IMC). Witnesses on the ground observed the aircraft flying at an extremely low altitude, estimated at roughly 50 meters, before it disappeared into the fog. The aircraft eventually struck the tops of trees on a ridge near Kindhausen/AG at an altitude of approximately 700 meters. The impact destroyed the aircraft and caused damage to the surrounding forest. The pilot sustained fatal injuries, while the passenger suffered serious injuries.
The investigation
Investigators examined the wreckage and flight records to reconstruct the final moments of the flight. Analysis of the debris showed that the aircraft's engine was producing power at the time of impact, with the throttle set at approximately 80%. The aircraft's weight and balance were within legal limits, and no mechanical failures or pre-existing defects were found in the engine or airframe.
Meteorological data from the time indicated significant fog and low cloud bases in the region. While the pilot held a valid private pilot license, her instrument rating was no longer current. The investigation also reviewed the pilot's flight planning and the available weather information, including METAR and TAF reports, which had indicated deteriorating visibility and low cloud ceilings.
Findings
- The primary cause of the accident was terrain impact resulting from the continuation of visual flight rules (VFR) while operating in instrument meteorological conditions (IMC).
- The pilot's assessment of the weather conditions was too optimistic, leading to a flight into deteriorating visibility.
- The aircraft deviated from its intended route toward the northwest, which directed it into rising terrain.
- The pilot's instrument training may have led to a false sense of security regarding the forecasted weather and the initial fog patches encountered near the departure point.