What happened
On 13 August 2018, a Boeing 737-800, registration EI-FJW, was on final approach to Runway 06 at Edinburgh Airport. Simultaneously, an Airbus A320-214, registration OE-IVC, was preparing for departure on the same runway.
A series of delays occurred during the departure sequence. The trainee air traffic controller cleared OE-IVC to line up, but the aircraft was delayed because the stop bar lights had not been extinguished. This delay, combined with a period of radio congestion, prevented the departing aircraft from beginning its takeoff roll promptly.
During the approach, the crew of EI-FJW maintained a groundspeed higher than typical for the arrival, as they had been instructed to maintain at least 160 KIAS. As the gap between the two aircraft closed, the trainee controller and the supervising instructor (OJTI) did not realize the severity of the situation until the landing aircraft emerged from the cloud. At the closest point of approach, the two aircraft were separated by approximately 875 m, with the departing Airbus A320-214 at 60 ft altitude as the Boeing 737-800 touched down.
The investigation
The investigation examined radar data, CCTV footage, and flight data from the Quick Access Recorders of both aircraft. Investigators also reviewed the training records of the trainee controller and the instructional techniques used by the OJTI.
Key areas of examination included the functionality of the Runway Incursion Monitoring and Collision Avoidance System (RIMCAS), the visibility of the controller's radar screens, and the effectiveness of the communication between the air traffic controllers and the flight crews. The investigation also looked into the impact of the stop bar's status and the visibility of the aircraft during the approach.
Findings
The investigation found that the trainee controller did not identify the narrowing gap between the aircraft. The investigation also noted that the trainee controller's view of the radar screens was partially obscured. Furthermore, the investigation found that the stop bar was not extinguished, which contributed to the delay in the departure of the second aircraft. The investigation also noted that the visibility of the aircraft during the approach was reduced due to the presence of clouds.
While the departing aircraft was delayed, the investigation concluded that the primary cause of the incident was the failure of the air traffic controller to maintain adequate separation between the two aircraft.