What happened
On November 12, 2011, at Tenerife South – Reina Sofía Airport, an Iberia Airbus A321 (IBE3415) was performing an ILS approach to runway 08. Simultaneously, a Boeing 757-200 (EXS518) was taxiing toward the same runway. The tower controller, seeking to expedite traffic, issued an immediate takeoff clearance to the 757-200 while it was still approximately 300 meters from the runway hold point on taxiway B1.
As the 757-200 proceeded to enter the runway and begin its takeoff roll without stopping, the incoming Airbus A321 continued its approach. The crew of the Airbus A32 and was aware of the departing traffic and maintained visual contact. The aircraft landed on runway 08 just as the 757-200 became airborne, resulting in a minimum separation of 1,250 meters between the two aircraft.
The investigation
The investigation examined flight data from the Quick Access Recorders (QAR) of both aircraft, radar data, and controller and crew statements. Investigators reconstructed the flight paths, revealing that the Airbus A321 was performing a "decelerated approach," a fuel-saving technique where flaps are extended later in the approach, resulting in higher speeds. Specifically, the aircraft was in a CONF3 configuration upon touchdown.
Analysis showed that the controller issued the takeoff clearance while the arriving aircraft was 6 NM from the threshold, but failed to account for the high ground speed of the incoming flight and the position of the departing aircraft. Furthermore, the investigation found that the controller did not utilize speed adjustment tools to increase separation and did not amend the takeoff clearance once the departing aircraft had passed the hold point.
Findings
- The tower controller issued an immediate takeoff clearance to the 757-200 while it was still on the taxiway, significantly reducing the available time to manage separation.
- The Airbus A321 was operating with a higher-than-normal approach speed due to a decelerated approach profile and a delayed flap configuration.
- The controller failed to implement speed adjustments for the incoming aircraft to maintain safe separation.
- There was an absence of specific written procedures or guidelines within the AENA network for managing immediate departure clearances in relation to the distance of approaching aircraft.
- The controller did not communicate with the arriving crew to coordinate an evasive maneuver or a go-around, and the arriving crew did not communicate their concerns to the tower.
Safety action
- It is recommended that AENA develop and implement specific procedures and training for tower personnel to manage immediate departure clearances, specifically considering aircraft type, ground speed, aircraft position, and local wind conditions.