What happened
On July 8, 2015, a Piaggio P180 Avanti departed from Szczecin-Goleniów (EPSC) bound for Milan-Linate (LIML). Shortly after takeoff, the aircraft was climbing through FL085 on a southward course. During the climb, the aircraft's flight path approached the active restricted airspace EP TSA 10A.
As the aircraft progressed, air traffic controllers at ACC GAT sector B noticed the flight plan would take the aircraft through the active zone. Controllers at the Szczecin tower informed the Bremen ACC that the aircraft was heading south, but noted that the Bremen controllers were unaware of the active status of the EP TSA 10A zone. While controllers attempted to coordinate a westward turn to avoid the area, heavy thunderstorm activity made such a maneuver impossible. Consequently, the aircraft continued its climb, eventually crossing the boundary of the restricted area at FL140 before climbing through FL150, at which point the airspace violation alert cleared.
The investigation
The investigation examined the coordination between the Szczec and Bremen air traffic control centers. It was established that the Szczecin tower controller had transferred the aircraft to Bremen ACC communications shortly after takeoff while the aircraft was still on a southward heading. While controllers at ACC GAT sector B identified the risk and alerted both the Szczecin tower and Bremen ACC, the Bremen controllers had not been notified that the EP TSA 10A zone was active. Furthermore, the investigation found that the aircraft's turn angle exceeded 45 degrees from its planned track, a deviation that required coordination by Bremen ACC.
Findings
- The primary cause of the airspace infringement was the lack of operational procedures for air traffic control personnel regarding the coordination of active restricted zones.
- The Letters of Agreement (LoA) between the Polish and Bremen ACC did not include a map identifying the EP TSA 10A zone, nor did they outline specific coordination procedures for this area.
- The crew was cleared to fly south to avoid thunderstorm cells, unaware that the flight path would intersect the active restricted airspace.
Safety action
Following the investigation, the Polish Air Navigation Services Agency (PAŻP) initiated several corrective measures:
- The Airspace Management and Operational Preparation Bureau was tasked with updating the LoA with Bremen ACC within six months to include a map of the EP TSA 10A zone and appropriate coordination procedures.
- The Air Traffic Services Bureau, in collaboration with the Airspace Management Bureau, initiated the implementation of new instructions (INOP ACC) to establish clear rules for informing adjacent ACC centers about the activity of border airspace zones.