What happened
On November 11, 2021, a Flydubai Airline Boeing 737 MAX 8, registration A6-FMC, was taxiing at Warsaw Chopin Airport (EPWA) for a scheduled flight to Dubai International Airport. After being instructed by the tower controller to line up and wait on Runway 29, the crew correctly read back the instruction.
While taxiing onto the runway, the crew requested confirmation of the next radio frequency, which the controller provided. However, despite not receiving a formal takeoff clearance, the crew initiated the takeoff roll at approximately 22:06:12 local time. Twelve seconds into the roll, the tower controller issued an emergency instruction to abort the takeoff immediately. The crew complied, bringing the aircraft to a stop at a speed of 89 knots. The aircraft came to a halt approximately 250 meters from the intersection with Runway 33, where a LOT Polish Airlines Boeing 737-800 was in the process of landing.
The investigation
The Polish State Commission for Aircraft Accident Investigation (PKBWL) examined radio communications and flight data. The investigation confirmed that the crew had properly read back the initial instruction to line up and wait. The commission noted that the controller had not provided wind information, nor had either party used the specific term "take-off" in their recent communications, which is the standard phraseology for granting clearance. The investigation also verified that the flight crew had received adequate rest periods prior to the flight and held all necessary licenses.
Findings
- The primary cause of the unauthorized takeoff roll was a partial loss of situational awareness by the flight crew.
- A contributing factor was the occurrence of confirmation bias, where the crew likely interpreted their existing intentions (to take off) as being supported by the controller's communications.
- The crew's request for frequency confirmation suggested a breakdown in monitoring the actual instructions received.