Overview
On 19 February 2017 at 12:31 UTC, a dangerous approach (rapprochement dangereux) occurred between two aircraft in the control zone of Sion Airport (LSGS). The incident involved a Cessna 172S and a Piper PA-28R-201, both operating under visual flight rules (VFR).
Aircraft and Flight Details
Aircraft 1 (HB-CZO) was a Cessna 172S, owned and operated by Flugschule Eichenberger AG. The flight was a training (ecolage) operation, with two pilots and one passenger on board. It departed from Hausen (LSZN) and was destined for Sion (LSGS).
Aircraft 2 (HB-PQY) was a Piper PA-28R-201, owned and operated by Motorfluggruppe Langenthal. The flight was a private operation, with one pilot and one passenger on board. It departed from Langenthal (LSPL) and was destined for Sion (LSGS).
Investigation Outcome
The Swiss Safety Investigation Service (SESE) opened an investigation on 24 February 2017. During the investigation, it became apparent that the serious incident was not due to technical, organizational, or systemic causes. Furthermore, risk-increasing factors identified during the inquiry had already been addressed in another investigation. Consequently, the SESE discontinued the investigation, citing that the contribution of the inquiry to prevention was very limited.