Background
The aircraft, a Piper PA-28-140 registered HB-OLM, was owned by Fliegerschule Birrfeld. The pilot held a private pilot license for one month with about 43 total flight hours, including 17 hours on type. He had no mountain or glacier flying experience.
Accident Flight
On 16 July 1967, the pilot departed Birrfeld at 1412 MEZ with his parents as passengers. The planned route included Sarnen, Brünig, Grimsel, and Simplon, with the intention to return via the Jungfrau region. Earlier that day, the pilot had completed a similar flight with two other passengers.
After passing Bettmeralp and Eggishorn at about 3000 m, the pilot followed the western shore of the Aletsch Glacier to the Konkordiaplatz. From there, he continued north into the Ewigschneefirn basin. He maintained an estimated 100 m above the glacier while climbing. The basin's slope averaged about 1:15 above a large icefall. The pilot reported that the stall warning light illuminated several times. He attempted to turn back but found speed too low. He then aligned the aircraft uphill and landed on the snow-covered glacier. The aircraft touched down from a few meters and stopped quickly in soft snow.
Aftermath
All three occupants sustained minor injuries: the pilot and his father suffered facial cuts, and his mother had a rib contusion. The aircraft sustained heavy damage to the landing gear and wings. The fuselage was largely undamaged but may have been subsequently damaged by tourists with ice axes. The aircraft was reported missing around 1800 hours. The next morning, it was located and the occupants were evacuated by helicopter.
Investigation
The investigation found no technical issues with the aircraft. Weather was good with weak winds, good visibility, and no significant turbulence. The report noted that the pilot misjudged the slope of the basin due to low height above ground and lack of visual references. He continued climbing despite stall warnings until the situation became untenable. The aircraft's climb performance was insufficient for the gradient; at the given weight and density altitude, the best climb ratio was about 1:20 to 1:25, while the slope averaged 1:15. The pilot's decision to fly in the center of the basin rather than along the sides reduced his options for turning.