What happened
On May 16, 2015, three aircraft flying under Visual Flight Rules (VFR)—a DR 48 Robin, a DA Diamond, and a DR 46 Robin—entered the controlled airspace of the Szczecin-Goleniów TMA (EPSC), specifically the Heringsdorf sector (EDAH). The intrusion was first detected by the Szczecin-Goleniów Tower controller via the Pegasus_21 radar system, which showed the first aircraft at 2,000 feet, followed by the other two aircraft at several-minute intervals.
During the event, a fourth aircraft, identified as a CRJ9, was observed descending from German airspace into the EPSC TMA toward the Heringsdorf airport. The controller noted that the descent path and speed of the CRJ9 were on a collision course with one of the VFR aircraft. This risk was compounded by a momentary loss of transponder signal from one of the VFR aircraft. To mitigate the danger, the Bremen Area Control Center (ACC) was notified and subsequently instructed the crew of the CRJ9 to abort their descent at 3,000 feet.
The investigation
The PKBWL investigation focused on why the VFR aircraft were able to enter the controlled sector undetected by the local tower and why the incoming commercial flight was not coordinated with the existing traffic. The investigation examined the communication between FIS Gdańsk, ACC Bremen, and the Szczecin-Goleniów Tower, as well as the functionality of the Pegasus_21 radar system and AFTN flight plan distribution.
Findings
- The investigation identified a lack of information from FIS Bremen regarding the three VFR aircraft entering the EPSC TMA.
- FIS Bremen provided the VFR pilots with an incorrect radio frequency.
- There was a failure in the radar system (Pegasus_21) to provide information regarding the flight of these aircraft, and no flight plans were present in the system.
- No flight plans were available in the AFTN (Aeronautical Fixed Telecommunication Network).
- ACC Bremen failed to notify the local tower of the approaching CRJ9.