What happened
On July 13, 197 and at approximately 19:50, a Piaggio FW-P149D, registration HB-EET, crashed in the Alp Schlawitz area near Grabs, Switzerland. The aircraft was conducting a private VFR flight from Speck-Fehraltorf to Bad Ragaz. After a brief stop in Bad Ragaz to drop off a passenger, the pilot began the return leg toward Speck-Fehraltorf.
During the flight, the pilot navigated through the Rheintal and entered the Walchenbach Valley. While flying at an altitude of less than 50 meters, the pilot initiated a tight left-hand turn. During this maneuver, the aircraft's nose dropped suddenly, leading to an accelerated stall. The aircraft struck the ground approximately 20 meters below the level of a nearby mountain hut. The impact destroyed the aircraft, and a subsequent post-crash fire consumed much of the wreckage.
The investigation
The investigation examined the aircraft's mechanical condition, the pilot's medical findings, and the environmental circumstances. Physical examination of the wreckage showed no evidence of pre-existing mechanical failures in the control linkages, engine, or propeller. The aircraft's weight and center of gravity were within permissible limits, and the engine was found to have been operating at high power at the moment of impact.
Post-mortem analysis of the pilot revealed a blood alcohol concentration of approximately 0.85 per mille. While the pilot was wearing his seatbelt, the passenger was likely not restrained. The investigation also considered the terrain and lighting, noting that the setting sun and haze could have created significant glare and visual illusions.
Findings
- The pilot initiated a turning maneuver at an altitude too low to safely recover if performance was lost.
- The pilot may have been deceived by the terrain, potentially mistaking the Walchenbach Valley for a different passage toward Toggenburg.
- The pilot's blood alcohol level was significantly above the established limits for flight safety.
- The aircraft entered an accelerated stall due to the high angle of attack during the tight turn.