What happened
On July 29, 2017, at approximately 18:35 local time, a dangerous close proximity between two aircraft occurred in the vicinity of La Côte Aerodrome (LSGP) in Switzerland. The first aircraft involved, an Eurocopter EC 120 B with registration HB-ZDS, was operating a commercial flight under Visual Flight Rules (VFR). The helicopter was traveling from Guldenen (ZH) toward its destination at La Côte.
Simultaneously, a second aircraft, a Piper PA-22-108 registered as HB-OTN, was conducting a private flight under VFR. This aircraft was operating locally, with both its departure and arrival points being La Côte Aerodrome.
The investigation
The Swiss Transportation Safety Investigation Board (SUST) opened an inquiry to examine the circumstances surrounding this airprox. The investigation focused on the flight paths and the proximity of the two aircraft during their operations near the aerodrome. As this was a preliminary information report, the investigation aimed to establish the basic facts of the encounter.