What aircraft was involved and where did it happen?

The accident on 1969-08-10 involved a BÖLKOW GMBH BO 207, registration D-EJBU, at Cavril, GR, CH.

What was the probable cause of the accident?

The accident was caused by the pilot flying toward the Maloja Pass at an insufficient altitude and realizing the danger too late, leading to a stall during an attempted emergency turn.

Bölkow Bo 207 crashes in Swiss Alps during attempted turn

A private flight involving a Bölkow Bo 207 ended in a fatal crash in the Orlegna riverbed after the pilot attempted an emergency turn to avoid terrain.

What happened

On August 10, 1969, a Bölkow Bo 207, registration D-EJBU, was performing a private flight from Milan to Munich with three passengers. After a refueling stop in Milan, the aircraft proceeded toward its destination, with Samaden identified as an alternate airfield.

As the aircraft entered the Bregell valley, it flew at a dangerously low altitude. While passing near Cavril, the pilot realized the aircraft was approaching the Maloja Pass at insufficient height. In an attempt to reverse course and avoid the rising terrain, the pilot initiated a steep right-hand turn. During this maneuver, the aircraft lost altitude and the airspeed dropped below the minimum required for flight. The aircraft subsequently stalled and plummeted into the Orlegna riverbed. The impact resulted in two fatalities (the pilot and one passenger) and two serious injuries to the remaining passengers. The aircraft was destroyed.

The investigation

Investigators examined the aircraft's maintenance records, the pilot's flight history, and the environmental conditions at the time of the accident. The Bölkow Bo 207 was found to be in good mechanical condition and within its weight and balance limits.

Analysis of the pilot's logbook revealed that while he was a qualified private pilot, he had very little experience with mountain flying and had no recorded alpine flights prior to this trip. Furthermore, the navigation charts found in the wreckage—ICAO 1:500,000 scale—were deemed inadequate for mountain operations as they lacked detailed relief and did not specify the height of the Maloja Pass. Witnesses reported seeing the aircraft flying very low, just above the treetops, before the sudden turn and subsequent crash.

Findings

The pilot lacked sufficient experience in mountain flying and had not received specific training for alpine environments.
The pilot's flight preparation was inadequate, likely due to reliance on low-detail charts that failed to clearly illustrate the terrain features or the height of the pass.
The pilot underestimated the aircraft's climb performance required to clear the terrain.
The aircraft entered a stall during a steep turn because the airspeed fell below the minimum threshold during the attempt to maneuver away from the rising ground.