On Tuesday 17 March 2015 an incident has occurred at Amsterdam Airport Schiphol where a vehicle drove close in front of a cargo plane which was taxiing. LVNL has started its own investigation into the cause of this this incident.
Supervision of ground vehicles
On an aerodrome, two different parties are responsible for supervising ground traffic. At Schiphol Airport specifically, LVNL oversees traffic in the movement area, including aircraft taxiing to or from runways and boarding gates, whilst the airport itself is responsible for ground vehicles and towage.
Incident investigation
LVNL’s primary safety task is to maintain the separation of aircraft from one another, and also from vehicles and other obstacles when on the ground. Air traffic controllers internally report any incidents falling within our area of responsibility, with the aim of learning lessons from them and so reducing the chance that similar occurrences will take place again in the future. All reported incidents are investigated by LVNL, as part of our ongoing commitment to improving safety.
Description of situation
In the afternoon of 17 March, an incident occurred at Schiphol on the runway system near the Pieter junction. The Kaagbaan (runway 06) was in use as the main landing runway.
A type MD11 cargo aircraft was scheduled to take off from the Polderbaan. It was parked on the Sierra platform on the south side of the airport. In order to reach the Polderbaan, the MD11 had to cross the Kaagbaan at the S2 point. The MD11 crossed the Kaagbaan after a type Embraer 190 (E190) aircraft had landed and had exited the Kaagbaan in a northerly direction at point S2. Both aircraft were moving towards the Pieter junction. At the same time, an aircraft tug was also driving via taxiway A towards the Pieter junction.
The tug was intending to cross the junction in a southerly direction to taxiway R. At the junction, the E190 turned right and followed its route via taxiway B. After crossing the Kaagbaan, the MD11 was to head for taxiway Q via the Pieter point. At the junction, the tug drove across the runway in front of the MD11. The MD11 crew had to brake hard in order to avoid a potential collision.
The ground radar data showed that the minimum distance between the centre points of the MD11 and the tug was an estimated 30 meters.
Investigation
Air traffic control reports all incidents that occur in practice within LVNL, in order to learn from them and to reduce the risk of such incidents in the future. Within LVNL, all reported incidents are investigated in order to be able to continuously improve safety. During the investigation, we examine different aspects of the incident, such as the cause of the incident, the severity of this incident and the safety risk or the risk of a recurrence. As soon as the results of the investigation are known, they are published in the investigation file on LVNL’s website.
Results of the investigation
LVNL processed the investigation into the incident during taxiing at Amsterdam Airport Schiphol. The summary of the investigation is presented below.
In the afternoon of 17 March, an incident occurred at Schiphol on the runway system near the Pieter junction. A type MD11 cargo aircraft was scheduled to take off from the Polderbaan. It was parked on the Sierra platform on the south side of the airport. In order to reach the Polderbaan, the MD11 had to cross the Kaagbaan at the S2 point. At that time, the Kaagbaan was in use as the main landing runway. Because of this, the MD11 had to wait about five minutes at the S2 point before it could cross the runway.
MD11 crosses runway and taxis behind the Embraer
On the instructions of air traffic control, the MD11 was permitted to cross the Kaagbaan after a type Embraer 190 (E190) aircraft had landed. The E190 exited the Kaagbaan on the left-hand side (heading north) via runway exit S2. This was the same point at which the MD11 was waiting to cross on the south side. The MD11 crossed the Kaagbaan at S2 immediately after the E190 had left the runway. The E190 taxied towards the A pier.
Because the Kaagbaan was in use as a landing runway, the MD11 crossed the runway at a relatively high speed. The MD11 taxied behind the E190 towards the Pieter junction. After leaving and crossing the Kaagbaan at point S2, both the E190 and the MD11 were under the supervision of air traffic control.
Responsibilities divided
Two parties are involved in the supervision of ground traffic on the airport site of Amsterdam Airport Schiphol (AAS): air traffic control (LVNL) and Apron Control (AAS). Air traffic control at Schiphol is responsible for supervising ground traffic at and around the available take-off and landing runways on the airport site, such as arriving and departing aircraft taxiing to a runway or gate that want to cross the available runway. Under the responsibility of LVNL, the airport (Apron Control) supervises the towing traffic on the airport site that is moving outside the available take-off and landing runways. Apron Control is also located in the control tower at Schiphol.
The aircraft tug drives towards the junction
In the meantime, an aircraft tug had also driven towards the Pieter junction via taxiway A, with the intention of crossing the junction in the direction of taxiway R. The aircraft tug was under the supervision of Apron Control.
Air traffic control instructed the E190 crew to turn right at the Pieter point and to continue taxiing via taxiway B. Taxiway B is the standard taxi route to the A pier. Pilots request and are regularly assigned a shorter taxi route via Taxiway A.
The driver of the tug saw the E190, braked and asked Apron Control where the E190 was heading. Apron Control said that the E190 was going to taxiway B and that the tug could cross the Pieter point after the E190 had moved onto taxiway B.
MD11 and tug at the Pieter point
Meanwhile, the MD11 crossed the Kaagbaan and approached the Pieter junction. At that moment, Apron Control spotted the potential conflict between the aircraft and the tug. Apron Control asked the driver of the tug whether he could cross the junction in front of the MD11. The aircraft tug then drove across the Pieter point in front of the aircraft.
The MD11 crew had to brake hard to reduce the risk of a collision. An analysis of the ground radar data showed that the minimum distance between the centre points of the MD11 and the tug was an estimated 30 meters.
The MD11 continued taxiing to the Polderbaan and took off without any problems.
Factors relevant to the investigation
- The E190 and the MD11 were under the supervision of air traffic control. The aircraft tug was under the supervision of Apron Control;
- As long as there are no additional instructions from air traffic control, taxiing traffic has right of way over other traffic, such as aircraft tugs;
- During the landing and crossing of the Kaagbaan, the E190 and the MD11 were under the supervision of the air traffic control tower. After leaving the runway, both aircraft were under the supervision of ground traffic control;
- Apron Control listens to the ground traffic controller frequency, but not the tower air traffic controller frequency. This is in accordance with the current working method.
- Apron Control saw the MD11 waiting at S2, but missed the moment when it made the crossing.
- Because the Kaagbaan was in use as a landing runway, the MD11 crossed the runway at a relatively high speed.
- The E190 blocked the view of the MD11 for the driver of the aircraft tug.
Recommendations
The learning points of this incident relate to the coordination between air traffic control and Apron Control and a clear understanding between the two of how the other party works. An understanding of each other’s working situation, clear agreements and where necessary, reconfirmation of agreements reached could probably prevent an incident like this in the future.
An initiative has now been taken for closer cooperation between the safety officers involved in Apron Control and the safety experts of LVNL. The aims of this cooperation include learning together from incidents and jointly identifying risks, so that safety can be improved further.
Classification: serious incident
Classificatie: ernstig incident