What happened
On 21 May 2011, a serious runway incursion occurred at Dublin Airport involving two commercial aircraft. An Airbus A321-231, registration G-OZBS, was taxiing toward runway 28 for departure. Due to the aircraft's heavy weight, the crew had requested the longer runway to ensure adequate performance. During the taxi, the crew mistakenly turned onto taxiway A, which led them directly onto the active runway 16.
Simultaneously, a Boeing 737-8AS, registration EI-DPT, was in the middle of its takeoff roll on runway 16. As the aircraft approached its decision speed, the flight crew spotted the G-OZBS encroaching on the runway. The captain immediately initiated a high-speed Rejected Take-Off (RTO). The Boeing 737-8AS came to a complete stop approximately 360 metres from the intruding aircraft. There were no injuries and no damage to either aircraft, though the Boeing 737-8AS required a technical inspection of its braking system following the intense deceleration.
The investigation
The AAIU investigation examined flight data recorders, cockpit voice recordings, and air traffic control audio. Investigators looked into the taxiway markings, the visibility conditions at the time, and the coordination between Ground and Tower controllers. The inquiry also reviewed the complexity of the airport's taxiway layout and the effectiveness of existing surface movement monitoring systems.
Findings
Several factors contributed to the loss of situational awareness by the crew of G-OZBS. The investigation established that the crew incorrectly assumed a passing aircraft was on a different taxiway, leading them to deviate from their assigned path. Environmental conditions played a significant role; the pavement was wet from recent rain, and bright sunlight reflecting off the surface made taxiway markings and runway signage difficult to discern. Additionally, the crew was likely distracted by cockpit tasks during a short, busy taxi sequence. The investigation also noted that while a stop bar was active on a different taxiway, the stop bar on taxiway A was not illuminated, which may have contributed to the error.
Safety action
Following the incident, Dublin Airport implemented several upgrades to its Air Traffic Management systems. This included the activation of Advanced Surface Movements Guidance and Control System (ASMGCS) Level 2, along with new runway incursion monitoring and conflict alert systems. Furthermore, the Irish Aviation Authority designated taxiway A as a runway incursion hot spot and updated procedures to prevent the simultaneous use of runways 16 and 28.