On Saturday 15 October 2022, an occurrence took place on the airport premises of Amsterdam Airport Schiphol. A departing aircraft was given clearance for push-back, while another aircraft was taxiing to the adjacent gate. The routes of the two aircraft were in conflict. As a result, the distance between the two aircraft was smaller than the usual safety margin.
Push-back involves pushing a plane backwards from the gate. After push-back, the plane can taxi, if it has received permission to do so.
LVNL has reported this incident to the Dutch Safety Board and is conducting its own investigation.
Description of occurrence and conclusions of the investigation
In the early morning of 15 October 2022, an occurrence took place on the south side of Pier D, near aircraft stands D22 and D24. This took place during the push-back of one of the aircraft while another aircraft was taxiing to the gate.
A Boeing 737-800 (B738) aircraft had landed on runway 18R/36L (Polderbaan) and was taxiing via taxiway Bravo to aircraft stand D22. The B738 was instructed to proceed to aircraft stand D22 via taxiway A6. Meanwhile, at aircraft stand D24, a Boeing B737-700 (B737) requested permission to start their engines and carry out the push-back procedure. Initially, the ground controller instructed the aircraft to wait, because of aircraft B738 which was on its way to D22. The ground controller checked the map displaying the direction in which this push-back procedure is normally carried out and authorised aircraft B737 to start its engines and perform the push-back procedure.
The ground controller spoke to the aircraft crew via radio frequency. In turn, that crew was in contact with the pushback truck. The ground controller asked the crew of aircraft B737, when giving permission for the push-back, to notify the pushback driver that the incoming aircraft at D22 was not a conflict. In addition, the aircraft en route to D22 was informed by the ground controller that the aircraft at D24 had been given push-back instruction and that this push-back would not get in the way of the taxiing aircraft.
Aircraft B738 moved into aircraft stand D22 and aircraft B737 was pushed backwards from D24. After both movements were carried out, the crew of aircraft B737 informed the ground controller that the pushback driver had reported to the pilots afterwards that he believed that there was not enough distance between the two aircraft. The ground controller realised that he had misinterpreted the map showing the push-back procedures and had understood that the push-back of D24 would be moving in the opposite direction. If that had been the case, it would have been possible to carry out a simultaneous movement with an incoming flight at D22 with sufficient space. Apron control from Amsterdam Airport Schiphol, in contact with the pushback drivers via radio frequency, asked the pushback driver concerned what had happened. The pushback driver who had pushed aircraft B737 backwards indicated that he did not move the push-back all the way up to the ‘push-back limit line’, but a bit further back, to leave more space for the inbound aircraft. The crew of aircraft B738 reported afterwards that they had cut the corner when entering aircraft stand D22 in order to keep more distance from the aircraft that was being pushed back.
The minimum distance between the wings of the two aircraft has been estimated to be around 3 metres. Both the pushback driver and the crew of aircraft B738 have indicated that they had reduced speed and carried out the movement cautiously. It was clear to both that the other aircraft would not be hit. There was no damage and both aircraft were able to continue their flight or route without further details.
The investigation revealed that there was human error in this occurrence, with the ground controller misinterpreting the information on the map. The findings from the investigation were fed back to the relevant ground controller for learning and will be shared with all ground controllers. In addition, LVNL is continuously looking for ways to improve the information for the controller and the way it is presented to the controller. The occurrence has been discussed in the Ground Movement Safety Team of the iSMS (a collaboration within the aviation sector focused on safety) to ensure that the aviation sector learns from such situations as well.
Classification: serious incident