What happened
On May 10, 1972, a Cessna 150J, registration D-EEAK, was conducting a VFR flight from Milan Linate toward Konstanz. After refueling at Milan Linate, the pilot did not seek an official weather briefing, instead relying on an informal opinion from a ground handling employee regarding favorable conditions.
As the aircraft climbed over the Alps, initially encountering haze, it progressed through the Leventina Valley. While the pilot initially experienced clear conditions, a developing north-side stall situation caused low-level clouds to obstruct the mountain passes. Upon reaching the Gotthard Pass, the pilot encountered a low cloud bank blocking the entrance to the Urserental. Attempting to find a gap in the clouds, the pilot descended, eventually finding himself unable to climb back over the pass due to the closing weather and the aircraft's performance limitations. Faced with worsening conditions and the closure of nearby passes, the pilot executed an emergency landing on a meadow between Andermatt and Hospental. The aircraft struck a marshy area and overturned, though no injuries were sustained by the pilot or the passenger.
The investigation
SUST examined the pilot's preparation and the meteorological conditions at the time of the accident. The investigation established that while the previous day's flight had been successful, the pilot's preparation for the return leg was insufficient. The investigation also looked into the technical state of the Cessna 150J, finding it airworthy with no pre-existing mechanical defects. Furthermore, the investigation reviewed the meteorological data, noting that a significant weather shift had occurred overnight, leading to a north-side stall and low stratus clouds in the accident area.
Findings
- The pilot failed to obtain an official weather briefing at Milan Linate, relying instead on an unauthorized opinion from a ground handling staff member.
- There was an inaccurate assessment of the alpine weather situation, as the pilot was unaware of the developing cloud cover.
- The pilot may have failed to sufficiently account for the aircraft's climb performance capabilities when navigating the terrain.
- The lack of clarity regarding the authority of ground personnel to provide weather information at the departure airport contributed to the inadequate flight preparation.