What happened
On November 16, 1972, a Piper PA-28-140 Cherokee, registration D-EGSL, was performing a VFR private flight from Friedrichshafen to Basel and back. The outbound leg was completed without difficulty. However, during the return flight, the aircraft encountered a heavy snow zone characterized by a low cloud ceiling and significantly reduced visibility.
As the aircraft moved through the Klettgau region toward Schaffhausen, the crew lost all geographical references. In an attempt to navigate, the pilot attempted to use the Schaffhausen NDB, but the crew's focus on the instrument caused them to lose sight of the Rhine river. The aircraft entered the Randen area, flying through hilly terrain near Hemmental and Stühlingen. While attempting an evasive or turning maneuver to locate a landing field, the aircraft's speed dropped below the minimum required for flight. The Piper PA-28-140 Cherokee struck the ground in a wooded valley east of Schleitheim, resulting in a post-impact fire. The crash resulted in one fatality and two injuries.
The investigation
SUST examined the flight preparations, the meteorological conditions, and the cockpit management during the final stages of the flight. The investigation established that the crew had obtained weather information in Basel, but due to a language barrier between the pilot and the meteorologist, the warnings regarding the approaching snow front were not clearly understood. Consequently, the pilots continued the flight despite the deteriorating conditions.
Investigators also looked into the command structure on board. It was determined that there was no clear definition of the pilot-in-command or the division of duties between the two pilots. This ambiguity persisted throughout the flight, leading to a situation where both pilots were making operational decisions and both attempted to control the aircraft during the final critical maneuver.
Findings
- The aircraft was flying in weather conditions that were below the minimum requirements for VFR flight.
- The aircraft's speed fell below the minimum safety threshold during a turning maneuver.
- There was a lack of clear command authority and functional distribution between the two pilots on board.
- Flight preparation was inadequate due to insufficient weather briefing and a failure to recognize the severity of the approaching weather front.