I've heard of many different types of controllers, but I'm not sure exactly what their responsibilities and interactions are.

Here are some examples:

  • En route controllers
  • Approach controllers
  • Ground controllers

What types of controllers exist and what aspects of a flight is each one responsible for?

  • 1
    $\begingroup$ May I ask why do you ask the question? $\endgroup$ Commented Dec 28, 2016 at 14:13
  • $\begingroup$ See also: What is a TRACON? $\endgroup$
    – mins
    Commented Dec 28, 2016 at 15:49

4 Answers 4


In Canada (and I believe similarly in the United States), there are four ratings which can be applied to an Air Traffic Controller license:

  • Airport Control
  • Terminal Control
  • Area Control
  • Oceanic Control

Within each of those ratings, the responsibilities are sub-divided a bit based on operational needs. For example, controllers at a tower (with an 'Airport Control' rating) would tend to be qualified in all aspects of tower operations including:

  • Clearance Delivery (issuing IFR clearances or assigning transponder codes)
  • Ground Control (issuing clearances for aircraft to move to/from the apron and runway areas via a taxiway system
  • Air Control (issueing clearances to aircraft in the runway environment and in the vicinity of the airport)

Terminal Controllers (if a terminal control area exists around the airport in question) would be responsible for flights in the immediate vicinity of the airport to approximately 20-50 nautical miles. Their responsibilities may include multiple small airports, just a single large airport, or even just one specific operation at an airport (such as arrival control or departure control). These controllers are usually allowed to apply a smaller amount of lateral separation between aircraft due to the dense nature of the terminal environment and the specific nature of their role.

Once the aircraft leave the terminal (if one exists), the Area Controller-sometimes called enroute control-takes over. They are responsible for anywhere between several hundred square miles of airspace to over several thousand square miles in the case of sectors in northern Canada.

In the case of an aircraft transiting the ocean, a specific type of area controller called an Oceanic Controller takes over. They possess slightly different training in order to safely separate aircraft over the ocean in non-radar airspace.


You can find a nice summary here on the FAA website or here on Wikipedia

But generally speaking,

At an Airport (and this very much varies by airport size!)

Note: if there is no tower at an airport (the case for many small airports) aircraft must self announce on the UNICOM Frequency. It should also be mentioned that some airports have towers that are only in operation some hours of the day, they are considered (if open) un-towered at other times.

There may be a Tower controller (if there is a tower): who deals with airplanes on, to and from the active runways.

There could be a designated ground controller who deals with traffic form the ramp to the runway (at KPNE where I fly the tower handles the ground operations during low load times). They will also handle the movements of other things like plows and service vehicles that may be active on or near the runway.

There may be Flight Data/Clearance Delivery who will give the planes their routes before departure (or any taxiing)

Terminal Controllers handle traffic in the radar terminal area (30-50 miles) from an airport.

Enroute Controllers provide information to airplanes in the air such as IFR instructions or VFR Flight Following (Load Permitting)

You can find the frequencies for the various ATC bodies in the Airport Facilities Directory. You can even listen in live to see whats going on at lots of major airports.


In Europe, an ATCO license contains the following:

  • One or more ratings
  • One or more rating endorsements
  • One or more unit endorsements
  • One or more language proficiency endorsements
  • A medical certificate

An ATCO certificate shall contain one or more of the following ratings:

  • ADV - Aerodrome visual (tower control without use of radar)
  • ADI - Aerodrome instrument (tower control with use of radar)
  • APP - Approach procedural (approach control without use of radar)
  • APS - Approach surveillance (approach control with use of radar)
  • ACP - Area control procedural (area control without use of radar)
  • ACS - Area control surveillance (area control with use of radar)

For each rating, the following rating endorsements are available:

ADV: None

ADI (at least one rating endorsement required):

  • AIR (Air Control)
  • GMC (Ground Movement Control) (without ground radar)
  • TWR (Tower Control)
  • GMS (Ground Movement Surveillance) (using ground radar)
  • RAD (Aerodrome Radar Control)

APP: None

APS (may have one or more rating endorsements, but not required):

  • PAR (Precision Approach Radar)
  • SRA (Surveillance Radar Approach)
  • TCL (Terminal Control)

ACP (no rating endorsements required):

  • OCN (Oceanic Control)

ACS (can have one, but not two, rating endorsements):

  • OCN (Oceanic Control)
  • TCL (Terminal Control)

In addition, an ATCO will need a unit endorsement, which is the authorisation to provide air traffic control service for a specific sector, group of sectors and/or working positions under the responsibility of an air traffic service unit. Basically, a certification that you know the local regulations at the unit you are working at.

A language proficiency endorsement is also required in English and, if applicable, in the local language if required.

Furthermore, there are instructor ratings available, but I think that it beyond the scope of your question.

Then of course all controllers need to hold a class 3 medical certificate for their ATCO license to be valid.

As you can see, with the number of ratings and rating endorsements available, there are a lot of different possible combinations. So the answer to "what types of air traffic controllers are there?" is not a simple one. Regardless, I hope the above gives you a general overview of how ATC licensing is structured in Europe.


The previous answers detail the air traffic controller types and their roles very well. However, I find this diagram quite helpful to visually recall the airspace divisions.Airspace Organisation

ACC: Area Control Center

APP: Approach/Departure Control

TWR: Tower

UTA: Upper Control Area

CTA: Control Area

TMA: Terminal Control Area

CTR: Control Zone

  • $\begingroup$ hi what mean stack area in the picture? $\endgroup$ Commented Jan 25, 2021 at 18:34

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