What happened
On October 13, 2015, a DHC-8-402, registration OE-LGL, was performing a visual approach to Lugano Airport (LSZA) under marginal weather conditions. While flying approximately 3 km southwest of the aerodrome, the aircraft's Enhanced Ground Proximity Warning System (EGPWS) issued a "Pull up" alert, indicating a dangerous proximity to the terrain. In response to the warning, the crew executed a missed approach following a procedure toward the PINIK waypoint. Following the event, the flight continued to its alternate destination at Milan-Malpensa (LIMC). There were no fatalities or injuries among the 55 passengers and crew on board.
The investigation
The Swiss Transportation Safety Investigation Board (SUST) examined the flight procedures and the coordination between aviation authorities. The investigation focused on the specific visual approach tracks used by the operator, which were developed internally and used for crew training. Investigators also reviewed the communication channels between the Lugano airport management and the Federal Office of Civil Aviation (FOCA) regarding flight procedure updates.
Findings
- The primary cause of the terrain proximity was the use of an unsuitable visual approach procedure developed and implemented by the airline, which did not align with any published procedures in the Swiss Aeronautical Information Publication.
- The crew performed a delayed decision to abort the approach, contributing to the risk.
- There was a lack of effective coordination and oversight regarding the approval of this specific approach procedure.
- A significant safety deficit was identified in the lack of information exchange between the airport authority and the FOCA, noting that the last relevant meeting with Lugano airport representatives had occurred as far back as 2005.
Safety action
Following the incident, the airline implemented several restrictive measures, including enhanced risk assessments for Lugano operations, increased pilot experience requirements for that specific route, and stricter monitoring of EGPWS compliance. The SUST issued a safety recommendation to the Federal Office of Civil Aviation (FOCA) to establish regular information exchange protocols with all Swiss airport operators utilizing IFR procedures.