Swiss Investigation of 2018 DR 400/180 Accident at Col Durand (HB-KEE)

Accident Overview and Aircraft Details On July 27, 2018, a single-engine, four-seat DR 400/180 aircraft, registered as HB-KEE, was destroyed in a controlled flight into terrain (CFIT) accident at Col Durand in the commune of Anniviers, Valais, Switzerland. The aircraft, manufactured by S.A. Avions Pierre Robin in France in 1995, was powered by a 180-horsepower Lycoming O-360-A3A engine and equipped with a fixed-pitch, two-blade metal propeller. The operator and owner was the Groupe de Vol à moteur Aéro-Club du Valais. ## Flight Sequence and Pilot Background The pilot, a Swiss citizen born in 1963, held a private pilot license with a single-engine piston qualification and had approximately 369 hours of total flight time, including about 250 hours on the type. The flight was a private visual flight rules (VFR) operation from Sion Airport (LSGS). The pilot had previously completed a similar alpine flight earlier that day with two passengers. For the fatal flight, the pilot departed at 15:37 with three passengers. The aircraft climbed along the Rhône valley, orbited over Chandolin and Grimentz, and crossed the Moiry Glacier at 16:05. ## Final Approach and Collision At 16:14, the aircraft overflew the Grand Cornier glacier at 3,450 meters. The pilot then performed two wide left turns over Roc Noir. At 16:21, the pilot turned southeast and maintained an altitude of 3,480 meters, approximately 250 meters above the glacier, at a ground speed of 80 knots. The aircraft was heading toward the eastern ridge of Col Durand, which has an elevation of 3,436 meters. The pilot initiated a right turn toward the col, and at 16:22, the aircraft struck the scree slope on the north side of the eastern ridge. ## Casualties and Environmental Impact All four occupants on board—one pilot and three passengers—sustained fatal injuries. The aircraft was destroyed, and the onboard hydrocarbons caused minor soil pollution. No fire occurred, and the emergency locator transmitter activated. ## Meteorological Conditions The weather at the time was sunny and warm, with visibility of 30 kilometers. The wind was from 260 degrees at approximately 10 knots. The temperature was 8°C, and the dew point was 2°C. The barometric pressure (QNH) was 1010 hPa. The density altitude was 13,300 feet (4,085 meters), a factor highlighted in the MétéoSuisse bulletin for that day.