What happened
On October 20, 1998, a Piper PA-28-161 Warrior, registration HB-PIY, departed Locarno airport for a VFR flight toward Salzburg. The aircraft was carrying the pilot and two passengers. While navigating the Val Morobbia toward the San Jorio Pass, the pilot realized the aircraft's climb rate was insufficient to clear the terrain. In an attempt to reverse course, the pilot executed a left-hand turn that directed the aircraft toward the mountainside. During this maneuver, the left wing struck a group of pine trees, causing the aircraft to crash into the slope. The impact triggered a post-crash fire that completely destroyed the wreckage. All three occupants sustained fatal injuries.
The investigation
The investigation examined the aircraft's mechanical condition, the meteorological environment, and the pilot's physiological state. Technical analysis of the wreckage, including the propeller and engine components, indicated that the engine was losing power at the moment of impact, though no pre-existing mechanical defects were found. Investigators also reviewed weather reports and witness statements from the Locarno tower, which noted that the pilot had been warned about specific meteorological hazards before departure.
Findings
Several critical factors contributed to the accident:
- The pilot utilized a flawed flight tactic by flying along the left slope of the valley, which exposed the aircraft to severe downdraft and turbulence caused by a north wind (foehn effect).
- The pilot's blood alcohol concentration was measured at 1.5–1.6‰, indicating significant impairment that contributed to the accident.
- The pilot failed to account for the known meteorological warnings regarding turbulence and downdrafts in the area.
- The aircraft's performance was insufficient to overcome the descending air currents and clear the pass during the attempted turn.
Safety action
No specific safety recommendations were recorded in the final report.