What happened
On April 21, 2015, at Gdańsk–Rębiechowo Airport (EPGD), a potential collision occurred involving a Boeing 737-800 and a Dash 8 (DH8D). At 18:37 UTC, the air traffic controller (TWR) authorized the pushback of the Boeing 737-800 from stand 23 onto taxiway M. One minute later, the Dash 8 landed on runway 29 and was instructed to taxi via taxiway M toward stand 21, a route that required passing behind stand 23.
As the Dash 8 proceeded, the ground coordinator notified the tower that the Boeinc 73 37-800 had not yet begun its pushback but was ready, and that the taxiing Dash 8 had not yet cleared stand 23. Upon receiving this information, the controller immediately canceled the pushback clearance for the Boeing 737-800. This intervention prevented the two aircraft from entering a conflict situation.
The investigation
The investigation examined the taxiway configuration and the controller's ability to monitor movement. It was established that the controller was managing heavy traffic, including coordinating the approach of a flight inspection aircraft. The investigation found that certain sections of taxiway M and several stands are not visible from the tower position. Furthermore, the complex layout of taxiway M, which connects to taxiway A6 in a U-shape, was found to be confusing for pilots, as evidenced by the Dash 8 crew questioning their route.
Findings
- The primary cause of the incident was errors in Air Traffic Management (ATM) operations, specifically the issuance of imprecise taxi instructions to the Dash 8 crew.
- The taxi instruction failed to account for the pending pushback at stand 23, which was critical because that area of the maneuvering area is invisible to the tower.
- The complex design of taxiway M contributes to pilot disorientation and complicates air traffic control oversight.
- The controller's lack of visual contact with certain taxiway segments prevents full compliance with standard procedures requiring continuous monitoring of all movement area traffic.
- The controller's timely reaction to the ground coordinator's report was the decisive factor in ensuring the safety of both aircraft.