What happened
On 25 August 2019, a single-engine PA-28RT-201, registered G-BVDH, was conducting a private VFR flight from Lausanne, Switzerland, to Perugia, Italy. The aircraft was carrying a pilot and two passengers. After navigating through the Rhone Valley, the pilot turned toward the Simplon Pass near Brig.
As the aircraft approached the pass, it was flying at an altitude of approximately 6,100 ft AMSL, which was 2,200 ft below the recommended altitude for that route. Witnesses observed the aircraft flying at a low height with a high pitch-up attitude. During a right-hand turn intended to reach the pass, the aircraft's left wing stalled, leading to a collision with the north-west face of the Hübschhorn. The impact resulted in three fatalities and a post-impact fire.
The investigation
The Swiss Transportation Safety Investigation Board (STSB) examined the wreckage, radar data, and flight planning software used during the flight. The investigation reviewed the pilot's flight history, noting that while he was experienced on the aircraft type, he had no specific training in mountain flying.
Investigators also analyzed the pilot's use of an electronic tablet, which was mounted on the control wheel and served as the primary navigation source. The investigation confirmed that the aircraft's engine was producing power at the time of impact and that the aircraft was within its weight and center of gravity limits. The investigation could not determine why the pilot chose an altitude significantly lower than the recommended safety margin for the terrain.