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HDG of avoid traffic

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Old 11th May 2010, 14:20
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HDG of avoid traffic

Does anybody know if there is any rules about how to give the heading when there is gonna make two aircrafts conflict or hit,because we are currently trying to find if we can make some regulations about it.
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Old 11th May 2010, 15:34
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Errr, "Don't" ?
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Old 11th May 2010, 15:40
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Unless of course you mean giving avoiding action to prevent a collision or loss of separation?

In which case it's something along the lines of:

[callsign] Avoiding Action, turn [left/right] immediately heading [xxx (degrees)], traffic [direction in clock code], [left to right/right to left/opposite direction], range [x] miles, [same level/x feet above/below].
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Old 12th May 2010, 14:06
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I did not mean how to say that ,but I meant how to issue the right heading to avoid the traffic ,as I know ACAS only give vertical guidance ,but we are trying to figure out if we can find a way to optimize how to give the right heading when two aircrafts are gonna to hit .
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Old 12th May 2010, 14:14
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The UK CAA publishes a document called "Radar Control Collision Avoidance Concepts", available here. Perhaps this is what you are looking for.
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Old 13th May 2010, 14:09
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Ok, I will check that ,thanks so much for the help.
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Old 17th May 2010, 17:23
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Issue a large heaing change, away from the conflicting traffic (best if you tell both), in a panicked tone - that should wake the crew up. Ideally, turns to the right, so as the captain can hopefully acquire the other aircraft visually. There is nothing optimal about it - do what you can to avoid a collision!!!
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Old 17th May 2010, 17:36
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There is a school of thought that says not to give any headings once aircraft are responding to TCAS as it will degrade their climb/descent performance. Obviously the problem is that ATCOs don't always know the aircraft are responding to TCAS until after the action has been taken by the pilots (unless they have an advanced system that tells them).

Hard to sit there on your hands as the symbols merge I know but that is one school of thought.
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Old 20th May 2010, 08:30
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I have read the file which is provided by reportyourlevel ,can somebody read the page 13 ,item 6.13.7 ,it said both left or right is likely to move the aircrafts apart most quickly.
Don't you think plane01 turn right and plane02 turn left is better ???
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Old 20th May 2010, 10:15
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If it has got to the stage where you have lost your required separation standard, and a collision seems imminent, best advice is to give emergency traffic and suggest an immediate heading based on the surveillance available.

At this stage the controller has lost positive control of the situation anyway .

Every situation is different, you can't regulate a left or right hand turn, give your controllers a framework and intelligent regulations to work within, and give them the confidence to make a decision in this scenario.

This controller has just made a large mistake by allowing the two aircraft to get into this situation, they will only be paralysed by trying to remember the other regulation/rule when they have a critical time period to make a decision. If you regulate either a left/right hand turn or climb or descend instruction (Uberlingen), they may well follow your rule but is this the best way to resolve this unique situation?
A regulation/rule may make the ANSP feel happy that they have covered off a problem but you need to remember that the idea is not to let the planes hit.

Experience = that thing you get just after you've needed it.

In this situation, the one size fits all rule hasn't been invented yet and never will be.

Last edited by max1; 20th May 2010 at 10:38.
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Old 20th May 2010, 12:54
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max1
You are right , but the reason I talk about this here is just wish to find a framwork and intelligent regulations to work within.Just wanna get some ideas.
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Old 20th May 2010, 14:41
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cauatc; are you asking for an example? If so, is it for :
a) Between two aircraft which are known to you ie both on your frequency.
or
b) One aircraft is known to you but the other is unknown?
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Old 21st May 2010, 01:12
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Thanks for asking , we have examples both in one frequency and two different ,we just wish to figure out if there is a simple guidance about how to make a turn when there is a tendency for two aircraft colission.The link which is provided by reportyourlevel but I just do not understand the last sample as you can see my question in previous reply.
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Old 21st May 2010, 08:26
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Originally Posted by climbwithagoodrate
Issue a large heaing change, away from the conflicting traffic (best if you tell both), in a panicked tone - that should wake the crew up.
Don't mess about, use the phrase "Avoiding Action" as well. That should definitely get their attention.
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Old 21st May 2010, 09:39
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Don't you think plane01 turn right and plane02 turn left is better ???
No.
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Old 21st May 2010, 10:32
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Depends if they're head on or converging/crossing tracks...
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Old 21st May 2010, 10:46
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As reportyourlevel suggests the UK CAA CAP 717 covers most eventualities, i/e. left/right & up/down.

Give it a read.

Cheers
 
Old 21st May 2010, 10:51
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Can you tell me the reason ? I think one turn left another one turn right will let those two separate faster.
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Old 21st May 2010, 13:34
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Sure. My need to explain it shows you have no ATC experience and hence have been telling porkies.

The a/c in that scenario are about 3 nm apart, and are at FL410. At this point, you are pretty much screwed. The only possible thing that you might be able to get out, in the time available, is to turn the 'northbound' to the right to pass behind the other (by a very small margin, and only if the pilot were to act immediately. If this were a real scenario, the pilots would already be getting RAs). Airline a/c maneuver very slowly at high altitude, so the geometry of this scenario dictates that turning the eastbound right, and the northbound left (which is your question, correct?) would only ensure the conflict worsens. For you solution to be a valid way out, you need to have enough room (time) available so that the a/c can turn away from each other BEFORE the northbound crosses the westbound's projected path, and vice versa. Does that make sense?
If you don't have that time, then you help by trying to stretch the time available before one crosses the others path. This is achieved by turning them BOTH the SAME direction (as described in the advice).
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Old 21st May 2010, 13:50
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cauatc check your pm's
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