Accident Summary
On Sunday, 4 August 1974, at approximately 1040 hours MEZ, a Piper PA-28-180 Cherokee, registration HB-OMR, crashed onto a glacier near the Jungfraujoch, about 600 meters southeast of the Sphinx gallery exit. The aircraft was destroyed and all three occupants were killed.
Flight History
At around 0940 hours, the pilot departed from Grenchen Airport with two passengers for an alpine sightseeing flight. The flight path, reconstructed from a passenger's film and witness statements, included landmarks such as Gemmi, Leukerbad, Gitzifurgge, Gasterental, Oeschinensee, Weisse Frau, Kanderfirn, Rottal, and the Jungfraujoch Observatory. The film ended with the camera pointing east, slightly below the observatory's viewing terrace.
In the final phase, after passing the notch between the Observatory and the Mönch, the aircraft flew toward the Oberes Mönchsjoch, then made a right turn back toward the notch, but the altitude was insufficient to clear it. A left turn followed toward the Trugberg, then another left turn back toward the notch, again too low. The pilot turned left again, and the aircraft disappeared into clouds. Shortly after, it emerged with a left bank of approximately 70° and crashed in a southerly direction onto the glacier. The crash site coordinates were 642.800/154.950 at an elevation of 3420 meters.
Aircraft and Crew Information
The aircraft was a Piper PA-28-180 Cherokee, a single-engine low-wing monoplane with fixed landing gear, manufactured in 1973 and owned by the Segel- und Motorfluggruppe Grenchen. It had a total of 363:55 flight hours with 176 landings at the time of the accident. Weight and balance were within limits.
The pilot held a private pilot license issued in 1967, validated for single-engine aircraft up to 2500 kg, and a restricted commercial pilot license issued in 1973. Total flight experience was 177:48 hours with 660 landings, including 1:25 hours and 15 landings on the accident type. In the previous 90 days, the pilot had flown 4:35 hours. The two passengers had no flying experience.
Weather Conditions
At the time of the accident, the area was mostly cloudy with 1/8 to 3/8 cumulus clouds at altitudes between 2000 and 3000 meters, and 5/8 to 7/8 altocumulus at 4200 to 4500 meters. Visibility in cloud-free areas was 50 to 70 km but deteriorating rapidly. Wind at 3500 meters was from the southeast to southwest at 25 to 30 knots. A witness at the Jungfraujoch weather station reported that at 0930 hours, the sky was 7/8 overcast with altostratus 800 meters above the station, and the station entered fog by 1040 hours. The weather forecast had indicated conditions for visual flight would become difficult due to an approaching cold front.
Wreckage Examination
The aircraft struck the glacier with a nose-down attitude of about 70° and a left bank of approximately 90°, on a slope inclined about 10°. The landing flaps were retracted, elevator trim was near neutral, altimeter set to 1016 mb indicated 6700 ft, airspeed indicator showed zero, the fuel selector was on the right tank, throttle was at full, and ignition was set to both. The VHF radio was tuned to 124.7 MHz (Zürich Information), VOR to 116.9 MHz (Willisau), and ADF to 366 kHz (Bern). An artificial horizon indicated left bank of about 90° during descent. No pre-existing defects were found in the control systems. The lap belts were worn and held during impact.
Probable Cause
The accident is attributed to the pilot flying into an area during a high mountain flight where a safe turn back was no longer guaranteed due to topographical and meteorological reasons.