Background
On 16 November 1972, two pilots and a passenger planned a VFR private flight from Friedrichshafen to Basel and return using a Piper PA-28-140 Cherokee, registration D-EGSL. The aircraft was owned by the Luftsportgruppe Friedrichshafen and was well-equipped with radio. The outbound flight in the late morning proceeded without difficulty.
Return Flight
Approximately two hours later, the return flight encountered rapidly deteriorating weather due to an active warm front bringing heavy snow, low ceilings, and poor visibility. During the flight, the crew lost geographical orientation after following the railway line Thiengen-Neunkirch-Schaffhausen. The assisting pilot could not read the frequency of the Schaffhausen NDB from the chart as he lacked his glasses. The flying pilot attempted to use the radio compass, but by then the railway line was lost from sight.
Accident Sequence
The aircraft flew into the Randen area, passing near Hemmental and Stühlingen. The passenger reported that ground visibility was completely lost at times. As the aircraft entered a steep valley east of Schleitheim, the pilots decided to turn back to land on a field the flying pilot had glimpsed. During a low-altitude left turn at about 100 m above ground, the aircraft stalled despite the flying pilot applying full power. The Cherokee crashed at approximately 1445 MEZ in a wooded ravine called "Chällen" (coordinates 682‘300/289‘000, elevation 680 m) and caught fire.
Wreckage and Injuries
The aircraft was destroyed. One pilot sustained fatal injuries and was found in the wreckage after the fire was extinguished. The other pilot and the passenger were slightly injured; they escaped through the torn cabin door and sought help from a nearby farm.
Probable Cause
The accident was attributed to: undershooting the minimum speed (stall), continuing the flight below the minima for visual flight rules, and inadequate flight preparation including poor weather briefing and unclear command authority on board.