What happened
On December 13, 2011, at Frankfurt Airport, a serious loss of separation occurred between two aircraft operating on parallel runways. An Airbus A380-800 arriving from Tokyo was on final approach to runway 25L. Due to a high flare and wind gusts, the crew initiated a missed approach, briefly touching the runway before climbing away.
Simultaneously, an Airbus A300-214 was positioned on runway 25C, preparing for departure to Moscow. At 14:25:30, the air traffic controller cleared the Airbus A320-214 for takeoff. At the time of this clearance, the Airbus A380-800 was already over the threshold of the parallel runway. As the Airbus A320-214 accelerated and rotated, the aircraft on the missed approach continued its climb.
Radar data indicates that the two aircraft eventually converged to a minimum horizontal distance of 0.97 nautical miles and a vertical distance of approximately 200 feet, significantly violating the required separation standards of 7 NM horizontally and 1,000 feet vertically. The Airbus A320-214 came within approximately 30 meters of the Airbus A380-800's wake turbulence. To resolve the conflict, the controller instructed the departing aircraft to turn, but the initial instruction led the Airbus A320-214 to turn toward the path of the climbing Airbus A380-800.
The investigation
The BFU investigation examined the sequence of events, the air traffic control (ATC) communications, and the operational procedures at Frankfurt Airport. The investigation reviewed radar data, Quick Access Recorder (QAR) data from both aircraft, and the performance of the controllers at the tower workstations. The investigators also analyzed the coordination between different controller positions and the adequacy of the existing departure and missed approach procedures for the parallel runways.
Findings
- The takeoff clearance for the Airbus A300-214 was issued before the landing of the Airbus A380-800 on the parallel runway could be secured.
- The controller failed to order a rejected takeoff for the departing aircraft despite the ongoing missed approach on the adjacent runway.
- A flawed mental approach by the controller resulted in an instruction for the departing aircraft to turn into the path of the climbing aircraft.
- The high rate of climb of the Airbus A320-214 (reaching up to 4,656 ft/min) contributed to the rapid reduction in vertical separation.
- Systemic issues included increased coordination workload due to the tower workstation organization and insufficient procedures for managing simultaneous departures and missed approaches on parallel runways.
- There was no established procedure for resolving conflicts once both aircraft were airborne in this specific scenario.