What happened
On March 31, 2015, an incident occurred at Warsaw Chopin Airport (EPWA) involving a Saab 340 (SF34). Following the issuance of NOTAM P(A)1370/15 at 22:55 UTC, a portion of taxiway A3 (specifically segment A3) and taxiway A1 were officially closed for operational use effective from 22:54 UTC. Despite this closure, a towing operation commenced on the restricted segment of taxiway A3 at approximately 23:07 UTC.
The investigation
The investigation established that the air traffic controller at the Warsaw Tower (TWR EPWA) provided authorization for the towing movement onto taxiway A, which directly contradicted the active NOTAM restricting access to that area. While the controller attempted to notify the ground personnel regarding the error, the communication occurred too late, as the towing vehicle was already entering the closed segment. Furthermore, the investigation found that the controller misunderstood the response from the personnel working on taxiway A.
Findings
- The primary cause of the incident was an error by the air traffic controller, who issued clearance to taxi on a taxiway segment that had been closed by NOTAM.
- The controller was unaware of the specific nature of the maintenance works being performed on the taxiway or the associated operational risks, and failed to verify these details.
- Communication breakdown occurred when the controller's attempt to correct the movement was hindered by a misunderstanding of the workers' responses.