Runway incursion

A runway incursion is understood to mean any occurrence at an airport involving an aircraft, vehicle or person being unintentionally in the protected area of a runway that is being used for aircraft landings and take-offs.

What is a runway incursion exactly?

A runway incursion has been internationally defined by  ICAO:

Any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle or person on the protected area of a surface designated for the landing and take-off of aircraft.

To prevent such situations occurring, prior to accessing the runway, permission must be obtained from the air traffic controller in the tower. The air traffic controller in the tower (runway controller) has various technical and procedural facilities that can warn him or her when the runway is occupied and therefore cannot be used for take-offs or landings. At Schiphol, the Runway Incursion Alerting System Schiphol ( RIASS) is active. 

Throughout the world, runway incursions are seen as being one of the more important safety themes in which a lot of time and money is invested.

Schiphol 

At Schiphol airport, sustained attention is given to reducing the probability of runway incursions.

The Runway Safety Team (RST) Schiphol is an advisory body within the Veiligheidsplatform Schiphol (VPS - Schiphol safety platform) with representatives from the aviation sector. Runway incursions are the team's most important safety theme and the team’s objective is to arrive at improvement and control measures based on runway incursions that happen and/or on detected trends.

Determining safety risk

In addition to being able to determine whether a certain situation can be classified as a runway incursion or not, the risk associated with or severity of the situation is particularly important. If a single aircraft was involved in a runway incursion, the severity - probability of a conflict - will have been low.

Internationally, four different categories of severity of runway incursions (A to D) have been identified. They are visualised below. 

How often do runway incursions occur at Schiphol Airport?

In the period 2012 through 2016, a total of 170 runway incursions occurred at Schiphol, of a total of almost 2.3 million flight movements. This represents 0.0075 percent of the total number of flight movements. In 2015 and 2016, the number of runway incursions at Schiphol rose, reversing the downward trend seen in the preceding years. In addition to the ongoing initiatives, in mid-2016 this was why this subject attracted additional attention and research intended to limit the chance of runway incursions occurring.

Investigation of causes

All runway incursions at Schiphol are investigated, irrespective of their severity. The most frequently occurring type of runway incursion concerns situations in which traffic is located on a take-off or landing runway without being authorised to be there.

The underlying causes are:

  • Misunderstanding in the communication between a pilot and an air traffic controller;
  • The complicated infrastructure of Schiphol airport;
  • The Situational Awareness of a pilot or an air traffic controller;
  • Procedures.


Tools to prevent the occurrence of runway incursions

Since 2011, all runways at Schiphol have been equipped with the Runway Incursion Alerting System Schiphol -  RIASS.

RIASS acts as a safety net in the air traffic control tower system. It generates an alarm if there is a possible risk of a conflict between aircraft and vehicles and between aircraft and aircraft on take-off and landing runways and the associated runway entrances and exits. As a result, if possible and necessary, an air traffic controller can take immediate and appropriate measures. Incidentally, the air traffic controller consciously not performing an action can also lead to a resolution of the safety-critical situation.

In addition to RIASS, through the course of time, various control measures have been implemented to reduce the number and severity of runway incursions, including:

  • The construction of a north taxiway around the Zwanenburg runway to limit the number of Zwanenburg runway crossings;
  • The construction of an alternative towing route around the end of the Aalsmeer runway to limit the number of tows crossing the Aalsmeer runway;
  • Holding awareness campaigns among pilots;
  • Publishing so-called ‘hotspots’ at the airport - locations where a relatively high number of runway incursions occur - on the map material officially used by pilots;
  • Installing Runway Guard Lights: flashing lights at all relevant take-off and landing runway entrances and exits;
  • Installing additional ground marking and signage near a take-off and landing runway;
  • Awareness campaigns, targeted at pilots and the drivers of vehicles.