Aircraft and Pilot Information
The aircraft involved was a Reims Aviation F152, registered as HB-CGT, privately owned and operated. The pilot, a Swiss female born in 1970, held a valid private pilot license. She had accumulated 245 hours and 29 minutes of total flight time, with 86 hours and 29 minutes on the accident aircraft type. Her last flight on this type occurred on 17 June 1997.
Flight History
On the morning of 26 February 2000, the pilot and a female passenger arrived at Zurich Airport to conduct a private sightseeing flight. The initial flight plan, filed at 0911 local time, proposed a route via Lustenau, Sargans, Chur, Disentis, Grimsel Pass, and Brienz to Bern. However, after evaluating the weather, the pilot changed the plan. At 1100, a new flight plan was submitted for a direct route to Bern using departure route 2, which passed over Katzensee, Gasometer Schlieren, and Bremgarten.
Accident Sequence
The aircraft departed from runway 28 at approximately 1123 local time. A position report came from over Katzensee at 1126 at 2000 feet. The next report over Gasometer at 1128 was broken, requiring ATC to request confirmation. The pilot was instructed to report over Bremgarten, but no further communications were received after 1137.
Witnesses reported seeing an aircraft flying very low, approximately 50 meters above ground, in the vicinity of Kindhausen. The aircraft appeared to turn and then disappear into fog. The passenger later recalled that after passing a gasworks, the surroundings became completely white with fog, and she had no visual reference. She remembered a brief moment when the aircraft flew close above treetops before losing sight again.
At about 1133, approximately five minutes after the Gasometer report, the aircraft struck the top of a wooded crest at an elevation of 700 meters. The impact was nearly horizontal and in a southwesterly direction. The left wing made first contact with trees, followed by the propeller. The wreckage came to rest along a 100-meter path beyond the crest.
Investigation Findings
The aircraft was properly maintained and had no pre-existing defects. The engine showed signs of power at impact: the throttle was at approximately 80% power, mixture rich, and propeller blades exhibited deformation consistent with engine operation. The landing gear was retracted, landing flaps were retracted, and the trim was set slightly nose-heavy. The altimeter read 8080 feet (likely a misreading; actual QNH was 1031 hPa).
Weather conditions at the accident site were reported as 1-2/8 patchy fog with base at 2000 feet MSL, 6-7/8 stratus at 2400-2500 feet, visibility 5-6 km, and wind variable around 3 knots. The GAFOR forecast for the route Zurich-Bern was XXM (indicating marginal VFR). The pilot had printed METAR and TAF information but no evidence of GAFOR notes was found.
The pilot's last flight had been more than two and a half years prior, after which she underwent instrument flight training. Her instrument rating was no longer current at the time of the accident. Toxicology tests showed no evidence of impairment.
Probable Cause
The accident was caused by contact with terrain after the pilot continued visual flight into instrument meteorological conditions (IMC). A contributing factor was an overly optimistic analysis of the weather conditions.