Occurrence
On 24 May 2022, a Cessna 525 (registration T7-ACA) and a Boeing 737-800 (registration SP-LWF) were taxiing at Warsaw Chopin Airport (EPWA). The Cessna had taxied to a holding point on taxiway D2 ahead of runway 15, with the Boeing behind it. The Cessna was instructed to turn left from taxiway A3 onto taxiway S3, while the Boeing was to proceed straight to the holding point on taxiway A0 for runway 15.
The ground controller (GND) granted the Boeing crew permission to taxi on taxiway A, believing the Cessna would quickly vacate A3 at S3. Approximately 22 seconds later, the GND controller transferred the Cessna to the tower controller, losing direct influence over its movement.
An Embraer aircraft was at the holding point on D2 ahead of runway 15, followed by a De Havilland aircraft. To maintain separation, the Cessna crew stopped on A3, and the Boeing also stopped behind it on A. As the Embraer entered the runway, the De Havilland taxied to the D2 holding point. The Cessna then taxied left and stopped at the intersection of A3 and S3, where the De Havilland had been. The Cessna crew deemed the distance behind the preceding aircraft correct. The Boeing crew began taxiing straight on A3 behind the Cessna at similar speed. They considered asking the GND controller to suggest the Cessna move forward but did not. Observing their left wingtip and the Cessna, they assessed collision-free passing as possible, but the distance assessment was incorrect. At 08:17:10 local time, the left wingtip of the Boeing struck the tail of the Cessna.
Both crews informed the GND controller. Airport services secured the scene. The aircraft taxied autonomously to apron positions and shut down engines. After inspection, the closed taxiway section was reopened. Neither aircraft was flyable due to damage. No occupants were injured. Visual meteorological conditions (VMC) prevailed; traffic intensity was high, with a departure queue on taxiway A. The GND controller was about 1,500 meters from the collision point and had surface movement radar (SMR) imagery showing both aircraft clearly. SMR imagery depicted the Cessna's stop at the intersection as a potential conflict, but observations regarding the Cessna's position were not exchanged between the Boeing crew and the controller.
Cause
The cause of the occurrence was the decision to taxi next to another airplane at the intersection of taxiway A3 and S3.
Contributing Factors
The following contributed to the occurrence: 1) Time pressure associated with the upcoming new calculated take-off time (CTOT) for the Boeing airplane; 2) Failure to use SMR imagery to assess conflicts between airplanes on taxiway A3.
Safety Measures
The operator did not formulate any preventive measures. The Commission did not propose safety recommendations.