What happened
On 14 April 2005, a Bell 206 B helicopter, registration HB-XXN, departed Zurich airport at 10:36 LT, bound for Bergamo-Orio al Serio, Italy. After departing Zurich, the aircraft was last tracked by primary radar over the northern end of Lake Zurich. Later that morning, between 11:00 and 11:30 LT, an eyewitness observed the helicopter flying at a low altitude near the Gotthard Pass, noting that the area was covered in snow and clouds.
When the aircraft failed to arrive at its destination, a search and rescue operation was initiated. At 18:05 LT, a Swiss Air Force search helicopter located the wreckage on the north face of a rock ridge at Pizzo della Valletta. The impact caused the aircraft to explode, and both occupants were fatally injured.
The investigation
The investigation examined the flight history, meteorological data, and the pilot's experience. Investigators reviewed the weather forecasts available at the time of departure, specifically the GAFOR route weather forecast. They also analyzed the aircraft's technical state, including the operation of the transponder and the emergency beacon.
Technical examinations of the Bell 206 B revealed no mechanical defects contributing to the crash. However, it was noted that the transponder was likely in standby mode, which prevented secondary radar tracking, and the emergency beacon's antenna was severed upon impact, making the signal difficult to locate.