View Full Version : Traffic separation vs traffic information

11th Jun 2009, 08:53
Maybe i'm in the wrong forum but...

Can someone tell me the practical difference between traffic separation and traffic information in terms of the service ATC provides.

Why am I confused? Take class A airspace for example.
IFR is separated from VFR but
VFR have only traffic information on other VFR yet...

a) both have the same restrictions in terms of airways clearance ie. you go where you are told and nowhere else and

b) they're not going to vector two VFR flights into each other (or let them fly into each other without taking action for that matter).

PS i'm in Australia

12th Jun 2009, 06:31
Traffic separation: ATC will give positive instructions that prevent two aircraft from getting too close to each other. Example: A is told to maintain 2000' or below, B is told to maintain 3000' or above.

Traffic information: ATC will give instructions that may or may not allow two aircraft to get close to each other. But they will tell each pilot where the other aircraft is. "See and avoid" applies! Example: A is joining the circuit on early left downwind. B is vacating the circuit via left crosswind. So A is told about B and vice versa, so the pilots will look out for each other and adjust their flight paths accordingly.

Note that in the second paragraph, the ATC instructions are quite vague, so there is a possibility that the two aircraft could be close to each other. On the other hand, ATC can be less specific, so can cope with more aircraft at one time. As long as both pilots are alert and the controller doesn't become too "controlling", both systems work well.

A good introduction to different airspace classes may be found here (http://en.wikipedia.org/wiki/Airspace_class).

16th Jun 2009, 02:23

Looking at it in terms of VFR vs IFR and that's pretty much cleared it up. Thanks for the clarification. :ok:

16th Jun 2009, 23:06
Well, separation is always required; it can be achieved by following instructions from an air traffic controller, in which case the flight is controlled. It may be achieved by the pilots, in which case the flight is uncontrolled. In various types of airspace, various separation services are offered/mandatory for different flights.

For practical purposes, I fly into both controlled (towered) airports and uncontrolled (AFIS) airports; with the former the responsibility for separation primarily lies with the controller (say class D airspace), while in the latter the responsibility rests with me (class G airspace), however, the AFIS service will give me information in a pertinent way.

And IIRC VFR is not permitted in class A airspace...

19th Jun 2009, 23:34
Well, separation is always required

I know what you mean bfisk, and yes aeroplanes mustn't get too close to each other.

But please note - when discussing ATC and airspace classes, the term separation carries a very precise meaning. In context, separation is not always required. It is not required in any airspace Class F or G, and it is only sometimes required in classes C to E.