I know that TWR, APP, and ACC control ATZ, CTR, and en-route; but I'm not sure about the control service which is responsible for monitoring TMA (APP or ACC?!).

Could you please clear the case (preferably by a European reference)?


1 Answer 1


It depends.

Air traffic control service in a TMA can be provided by either an air traffic control tower (TWR), an approach control unit (APP), or an area control unit (ACC) - or any combination of those.

A TMA is typically considered to be APP airspace, but there is no rule preventing a TWR or ACC from covering a TMA, and there are many examples of this happening throughout the world.

The typical division, if you need a simple answer, is:

  • TWR provides service in a control zone (CTR)
  • APP provides service in a TMA
  • ACC provides service in a control area (CTA)
  • $\begingroup$ Sorry for my confusion. You have eliminated ATZ and en-route in your classification. What did happen to ATZ (have you considered it equivalent to CTR?), and do you mean that CTA is the same as en-route? $\endgroup$
    – user22587
    Jun 26, 2017 at 6:24
  • $\begingroup$ ATZ is a UK thing, it is not used in the rest of the world. En-route is not an airspace, it is a phase of flight. $\endgroup$ Jun 26, 2017 at 6:37

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