Incident Details
On March 31, 2015, at approximately 23:07 UTC, a Saab 340 (SF34) aircraft was being towed at Warsaw Chopin Airport (EPWA). The air traffic controller (TWR) issued clearance for the tow to proceed on Taxiway A, specifically the Alpha 3 (A3) section. However, this section had been closed for operations by NOTAM P(A)1370/15, which was published at 22:55 UTC and stated that Taxiway A1 and a portion of A3 were closed from 22:54 UTC.
Findings
The investigation revealed that work on Taxiway A3 had started with the permission of the TWR controller at 23:07 UTC, after the NOTAM had already closed the area. The controller incorrectly granted clearance for the tow, contradicting the earlier permission given to the company performing work on the taxiway. The controller attempted to inform the workers about the conflict, but the notification came too late—the towing aircraft was already entering the closed taxiway. Additionally, the controller misunderstood the response from the workers on the taxiway.
The controller was unaware of the specific type of work being conducted on the taxiway and the associated hazards. No attempt was made to verify the nature of the work.
Cause
The incident was caused by an error by the Warsaw Chopin Airport air traffic controller, who issued clearance to taxi on a taxiway that was closed by a valid NOTAM.
Preventive Actions
The investigating body (the air navigation service provider) took the following preventive measures:
- The final report and collected materials were forwarded to the Warsaw Airport Control Department to inform the controller about the outcome of the proceedings and the report's findings, aiming to reduce the likelihood of similar events.
- The report and materials were also sent to the ATS Personnel Training Center to be included in the database of investigated events used by instructors during initial and refresher training for air traffic controllers.
No safety recommendations were issued by the commission.