What happened
On September 27, 2019, at Warsaw Chopin Airport (EPWR), two Boeing 73 and 800 aircraft were involved in a potential collision incident on the apron and taxiway system. The aircraft SP-RSV had received clearance to push back from stand 10 and proceed via taxiways B and C toward runway 11. During this movement, the air traffic controller (TWR) issued clearance for the pushback and engine start of aircraft SP-RST, which was positioned at stand 4.
During the initial radio communication, the crew of SP-RST provided their position in a manner that the controller interpreted as stand 14. Relying on this information, the controller did not seek further verification of the aircraft's actual location. The situation was identified when the crew of SP-RST observed the taxiing SP-RSV on taxiway B and alerted the controller. Upon investigation, the controller queried the aircraft's position, subsequently rescinding the pushback clearance for SP-RST. Once SP-RSV had cleared the area, the controller reissued the pushback and start clearance for SP-RST from its actual location at stand 4.
The investigation
The PKBWL investigation focused on the radio communications between the flight crew of SP-RST and the tower controller. The investigation established that the controller operated under the mistaken belief that the aircraft was located at stand 14. The inquiry examined the sequence of verbal exchanges to determine how the discrepancy between the actual position (stand 4) and the perceived position (stand 14) occurred.
Findings
- The primary cause of the incident was the issuance of pushback and engine start clearance to SP-RST based on the controller's incorrect belief regarding the aircraft's parking position.
- A contributing factor was a misunderstanding during radio communications regarding the specific stand number occupied by the aircraft.