What happened
On 28 September 2021, an Etihad Airways Boeing 787-9, registration A6-BLL, was preparing for a scheduled passenger flight from Abu Dhabi International Airport to Jeddah, Saudi Arabia. The aircraft was carrying 224 passengers and 11 crew members. During the departure sequence, the airport was managing complex traffic, including a military aircraft and an ongoing runway calibration flight operating on a parallel runway.
After being cleared to line up and wait, the flight crew received takeoff clearance from Aerodrome Controller South. However, during the transmission of this clearance, Aerodrome Controller North intervened with non-standard instructions to halt the departure. Following this, the controller attempted to cancel the takeoff clearance but addressed the crew using an incorrect callsign, mistakenly combining elements of the military aircraft's callsign with the Etihad flight number.
Because the crew did not recognize the incorrect callsign, they continued the takeoff roll. It required four separate attempts by the controller—eventually using the correct callsign—before the crew acknowledged the instruction to stop. The crew executed a high-energy rejected takeoff, reaching a ground speed of 127 knots before successfully bringing the aircraft to a halt approximately 1,850 meters from the runway threshold.
The investigation
The GCAA AAIS investigation examined flight data recorder (FDR) and cockpit voice recorder (CVR) data, alongside air traffic control transcripts. The investigation focused on the coordination between Aerodrome Controller North and South, as well as the accuracy of the communications provided to the flight crew. Investigators also reviewed the airport's standard operating procedures regarding calibration flights and runway usage.
Findings
- The primary cause of the high-speed rejected takeoff was the issuance of a takeoff clearance that did not comply with established procedures.
- The controller used an incorrect callsign when attempting to cancel the takeoff, which led the crew to continue the takeoff roll.
- There was a significant lack of coordination between the North and South Aerodrome Controllers.
- The controller provided prolonged, non-standard traffic information during a critical phase of flight.
- Existing airport procedures (ATSOM) lacked sufficient specific instructions for managing traffic during calibration flights involving opposite-direction operations.
- The controller used non-standard phraseology when instructing the crew to cancel the takeoff.