Delta A333 at Amsterdam on Apr 18th 2012, runway incursion

The Dutch Safety Board (DSB) released their final report concluding the probable cause of the incident was:

The crew missed the relevant hotspot on the airport chart. The term “cross” in the taxi instruction “cross at Z2” gave the captain the impression that he had a clearance to cross the runway. He no longer followed the instructed route to Z2 but instead turned left, crossing the runway at the end and thus causing a runway incursion at W11. The stop bar at that intersection was not illuminated. There was no risk of a collision.

The DSB analysed that the aircraft had landed on runway 18R, the ground controller at Tower West subsequently instructed the aircraft to taxi to their gate via taxiway Z. About 4 minutes later the aircraft was handed off to ground controller north, the aircraft was approaching the intersection taxiway Z and W11 at that time. The intersection is identified as a hot spot on the charts released by AIP Netherlands and the charts used by the crew. The first officer checked in with ground control north reporting the aircraft was on taxiway Z and received the clearance "cross at Z2, taxi Alpha North to gate E17".

The first officer looked to identify the taxiway Alpha North, the second first officer in the observer seat looked over his shoulder to assist in finding Alpha North. The captain made a left turn, the stop bars were not illuminated and continued across the runway. The second first officer in the observer seat noticed that Z2 was south of and well clear of the runway and made the captain aware, however the aircraft had already crossed most of the runway at that point. The captain saw the W11 sign and realized he had taken the wrong taxiway and had just caused a runway incursion, he observed an aircraft on an about 3nm final to runway 18C and expedited the crossing just about at the same time when the ground controller instructed the aircraft to expedite crossing. The aircraft vacated the runway and continued to the gate without further incident.

The DSB analysed: "At the moment the Airbus A330 crossed the end of runway 18C at W11, a passenger aircraft was on final for runway 18C from the north for a full stop landing. The approaching aircraft was approximately 3 NM (5,5 km) before the beginning of runway 18C. Including the length of runway 18C, the total distance between the approaching and the crossing aircraft was about 5 NM (9 km). There was no risk of collision."

The DSB further analysed: "In the instruction of the ground controller the term “cross” was used. The captain interpreted the instruction as a clearance to cross runway 18C. The Captain made a left turn and crossed 18C at the end. The captain by then had observed the W11 sign and realised that he had taken the incorrect intersection." The DSB added, that the two first officers had also understood they were cleared to cross the runway, and later provided testimony that the term "cross" was misleading as Z2 did not cross the runway but only the extended runway center line.

The DSB concluded analysis: "The initial taxi instruction given to the crew by the Ground Controller West reads: “taxi via Z to E17”. In the instruction the word “via” is. Later on, Ground Controller North instructs the crew to “cross at Z2. Taxi Alpha North to gate E17”. This instruction did not state the words “via Z” which, in combination with the position of the aircraft when the clearance was given, namely at the end of runway 18C, may have contributed to the confusion on the flight deck."

As result of this and other occurrences, where aircraft turned left onto W11 instead of continuing to Z2, taxiways W11 and W12 were temporarily closed and barriers established until the intersections had been redesigned to prevent turning left to southbound aircraft while permitting turning right to northbound aircraft on taxiway Z.

The taxiway layout at the time of the occurrence (Graphics: DSB):

The taxiway layout after redesign (Graphics: DSB):