What happened
On May 12, 2020, a Cessna 206, registration SP-KWK, was conducting a flight from EPKT to EPBY. The aircraft was operating at FL 100 within Class C controlled airspace provided by GAT ACC1, while maintaining communication with FIS2 centers.
Initially, the FIS Poznań controller informed the crew of the activity within the TRA22 zone, specifically noting that the TRA22A segment extended from 3,500 ft AMSL up to FL 95. However, upon establishing contact with FIS Gdańsk, the crew received different information. The FIS Gdańsk controller incorrectly stated that the upper limit of the TRA22A segment was 4,500 ft AMSL. Relying on this inaccurate data, the crew decided to descend from FL 100 to 5,000 ft AMSL, operating under the impression that they were entering uncontrolled airspace.
A planning controller at GAT ACC identified a potential airspace violation and alerted FIS Gdańsk. Although the FIS Gdańsk controller instructed the crew to execute a left turn to avoid the zone, the aircraft subsequently entered the TRA22A segment at approximately 09:00 UTC.
The investigation
The investigation examined the coordination between the aircraft crew and air traffic services. It was established that because the aircraft was operating in GAT ACC controlled airspace, it required active air traffic control services. Instead, the crew remained in contact with FIS centers, which do not provide such services. The investigation also noted that the coordination for the flight through GAT ACC airspace was improper. Under SERA regulations, the flight at FL 100 was appropriate for IFR operations, but the lack of proper ATC coordination contributed to the incident.
Findings
- The primary cause of the incident was the transmission of incorrect information regarding the upper altitude limit of the TRA22A segment to the crew by the FIS Gdańsk controller.
- A contributing factor was the FIS Gdańsk controller's incorrect reading of the upper boundary value for the TRA22A segment.