What happened
On October 21, 2024, at 08:05 local time, a separation incident occurred at Tenerife North Airport (GCXO) involving two commercial aircraft. The first aircraft, a Boeing 737-8AS (registration EI-DYD), was on final approach to runway 30. Simultaneously, an Embraer ERJ 190-400 (registration EC-OEA) was performing its takeoff roll on the same runway.
As the Boeing 737-8AS approached the threshold, the tower controller issued a takeoff clearance to the Embraer 190-400 despite the arrival being in short final. The crew of the Boeing 737-8AS requested landing clearance and was initially told no, due to the departing traffic. However, the controller subsequently issued a landing clearance while the runway was still occupied by the departing aircraft. Realizing the conflict, the crew of the Boe/ing 737-8AS immediately initiated a missed approach maneuver. The minimum separation between the two aircraft dropped to 1.1 NM and 0 ft vertical separation.
The investigation
The CIAIAC investigation examined the sequence of communications and the management of the tower service. The investigation focused on the timing of the takeoff authorization and the workload of the air traffic controllers. The investigation also reviewed the impact of ground vehicle movements on the runway operations, noting that a pushback maneuver of another aircraft required a landing aircraft to use a different taxiway exit, which contributed to delays in the sequence.
Findings
- The primary cause of the loss of separation was a late takeoff authorization issued while another aircraft was already on short final and had been cleared to land.
- A contributing factor was the delay in the instructor controller recognizing that the trainee controller was unable to manage the increasing complexity of the situation effectively.
- High controller workload was exacerbated by the requirement for vehicles on the airport perimeter road to notify control at nine different points, leading to an excessive number of communications.
- The investigation noted that the takeoff clearance for the Embraer 190-400 was delayed because a recently landed aircraft had to use exit E2 due to a pushback restriction on a nearby stand.