Separation of aircraft

To ensure safe air traffic both on the ground and in the air, aircraft and other vehicles must remain at a sufficient distance from each other. Air traffic control is responsible for separation on the ground and in the air.

Separation standards

At the airports, air traffic control separates traffic in the so-called maneuvering area. This is the part of the airport site intended for take-off, landing and taxiing of aircraft, with the exception of the aprons. The boundary line between the maneuvering area and the platforms is indicated with red lines.

The horizontal or vertical distance between aircraft during flight is referred to as separation. The minimum separation is intended to ensure safe air traffic and at the same time make optimal use of the capacity of the airspace. With separation minimums we create buffers that reduce the chance of a collision.

Air traffic control is responsible for maintaining minimum separation between aircraft in the air traffic control area. Air traffic controllers provide aircraft crews with course, altitude and/or speed instructions, so that these minimums are not infringed.

Within the local air traffic control area of an airport - the control zone (CTR) - visual separation may also be used: as long as the air traffic controllers can observe both flights or both pilots have each other in sight, visual separation applies. This is necessary, for example, for the separation of two consecutive take-offs, but also for the handling of air traffic that flies 'on sight', the so-called VFR traffic, in the airspace directly around an airport.

Another form of separation takes place during parallel landings. Schiphol has three runways that are parallel to each other. When aircraft approach runway 18R and runway 18C simultaneously, they fly closer to each other than the standard prescribes. This is due to the geographical situation of the extended runways. If the aircraft fly on the fixed course for the approach, linked to the instrument landing system for that runway, the reduced separation is in accordance with the rules.

In aviation, a distinction is made between air traffic that fly 'by sight' (visual) and flights that fly 'on instruments'. Flights that fly 'on sight' are usually smaller aircraft. This traffic is called VFR traffic. VFR stands for Visual Flight Rules. Air traffic that flies 'on instruments' is called IFR traffic, where IFR stands for Instrument Flight Rules.

To make the VFR traffic as independent as possible from the IFR traffic, geographical separation can be used. Specific areas have been established for this purpose, such as the VFR sector and ILS areas, or areas in the extension of the runway with an instrument landing system (ILS).

Reduction of separation is permitted if the aircraft in question are part of so-called 'aerodrome traffic' (air traffic in the vicinity of an airport), and:
1. Sufficient separation can be given by the runway controller if each aircraft is continuously visible to her/him, or
2. Aircraft are constantly visible to the pilots and these pilots indicate that they can maintain their separation themselves, or
3. In the case of following aircraft, the pilot of the rearmost aircraft reports that he has the aircraft in front of him in sight and confirms that (s)he can maintain the separation (her-)himself.

Separation of aircraft

Separation standards

Separation on the ground

Separation in the air

Exclusion from standard separations

Visual separation

Separation during parallel approaches

Geographical separation

Reduced separation for aerodrome traffic