What happened
On May 19, 2020, at approximately 10:45 local time, a serious airprox occurred at an altitude of roughly 5,800 feet MSL near Wasen, Switzerland. The incident involved two aircraft operating under Visual Flight Rules (VFR). The first aircraft, a Pilatus PC-7 with registration HB-HMU, was conducting a private flight originating from and returning to Triengen Airport (LSPN). The second aircraft, a Cessna 172S registered as HB-TEE, was engaged in flight training operations. This aircraft had departed from Bern Airport (LSZB) with a destination of the same airport.
The investigation
The Swiss Transportation Safety Investigation Board (SUST) has launched an investigation to determine the circumstances surrounding this dangerous close approach. The preliminary report focuses on the flight paths and operational conditions of both aircraft at the time of the encounter near Wasen. As this is a preliminary report, the investigation is ongoing to establish the full sequence of events and identify any contributing factors.
Findings
At this stage of the investigation, the primary finding is that a dangerous close proximity between the two aircraft occurred at an altitude of approximately 5,800 feet. Further analysis is required to determine the specific maneuvers or visibility factors that led to the near mid-air collision.