1972 Pilatus Porter HB-PAD accident at Plateau du Trient

Accident details and flight phase On 23 April 1972, a Pilatus Porter with registration HB-PAD, operated by Air Glaciers S.A. Sion, took off from Sion at 0855 local time. The aircraft carried seven skiers bound for the Glacier du Trient. It landed heavily in the snow at 0915 at coordinates 567.200 - 093.700, 3360 m/M, where the right landing gear failed. ## Aircraft and pilot The pilot, born in 1934, held a valid professional licence and was qualified for professional mountain landings. The pilot had 1287 flight hours, including 120 hours on the Pilatus Porter, and 1180 mountain landings. In the 90 days before the accident, the pilot had 71 hours, including 36 on the Pilatus Porter, and 235 mountain landings. The aircraft held valid certificates of airworthiness and admission to traffic, and weight and balance were within limits. ## Weather and cause The weather was characterised by a light barrier effect on the south side of the Alps, with variable cloud over the Valais Alps. The Plateau du Trient was in shadow at the time. The wind was from the south at 15 knots at 3500 m/M. The Commission concluded unanimously that the accident was caused by a distance judgment error by the pilot, due to diffuse lighting. ## Damage and injuries The pilot and seven passengers were uninjured. The aircraft was severely damaged. No other damage was reported.