What happened
On March 28, 1971, a Cessna 172 F, registration D-EJZE, departed from Egelsbach, Germany, on a private VFR flight intended for Geneva. The aircraft was carrying the pilot and his wife. After communicating with air traffic control in Freiburg i.Br. around 13:00, the aircraft disappeared from radar contact. At approximately 14:00, the plane collided with the terrain on the northern slope of the Chasseral in the Swiss Jura mountains. The impact resulted in two fatalities and the total destruction of the aircraft.
The investigation
The investigation, conducted alongside German and Bernese authorities, examined the aircraft wreckage, weather reports, and the pilot's flight planning. Investigators found that the engine was operating at normal power at the time of the impact, as evidenced by a notch on a propeller blade and witness testimony from a nearby mountain hut. The wreckage showed the aircraft was flying at a high speed of approximately 170 mph, which reconstruction flights suggested required a significant nose-down pitch.
Navigation documents found at the scene indicated the pilot had planned a route through Spain and North Africa, but for this specific leg, he had plotted a course using radio beacons. Notably, the aircraft was found approximately 13 km west of its intended flight path.
Findings
- The pilot attempted to cross the Jura mountains despite insufficient visibility for VFR operations due to dense fog and low cloud ceilings.
- Meteorological data confirmed heavy cloud cover and low visibility (3–6 km) north of the Jura range.
- The pilot had been advised by a meteorologist in Frankfurt earlier that day to avoid the Jura and instead fly via the Saône-Rhône Valley to maintain VFR conditions, but he proceeded with the original plan.
- It is believed the pilot, perhaps thinking he had already cleared the mountain range, attempted to descend through the cloud layer, leading to the collision with the snow-covered terrain.
- There were no mechanical failures or health issues identified that would have prevented the pilot from controlling the aircraft.