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View Full Version : Giving way - who ets preference from ATC


JeroenC
2nd Apr 2014, 22:23
Hello,

the other day we (B737) were flying at our filed cruise level (think FL370). ATC asked us to descend to allow a converging 777 to overtake us, after which we could climb again.

Are there rules/guidelines who gets "right of way" in this scenario? I found it a bit strange. Maybe LoCo vs legacy, or narrow body vs wide body?

Tnx for answers!

chevvron
3rd Apr 2014, 00:15
Personally I would apply standard rules of the air ie the one which has the other on its right should give way, however I once had 2 a/c at FL370 on crossing upper air routes, told them about each other and they sorted it out themselves using their own radars/eyeballs.

JeroenC
3rd Apr 2014, 00:23
We were on the right...

jmmoric
3rd Apr 2014, 01:00
According to DOC 4444 the preeceding aircraft normally has priority when they're both at the same level.

Other than that, no rule applies.

EastofKoksy
3rd Apr 2014, 07:01
To the best of my knowledge there are no rules in this situation.

I was trained to try to leave both aircraft at their preferred levels and use radar headings to get them passed each other. Only if that is not possible (e.g if very busy) I will apply my own 'rule' of whichever aircraft has furthest to go stays at its level, the other descends and can climb back to the level later if it wants to.

In Europe there seem to be some countries where ATC generally resolve conflicts vertically and others where radar headings are the preferred solution.

ferris
3rd Apr 2014, 08:40
The most important rule applies. i.e.

Whatever suits the controller better.

I could go into a long-winded explanation, but it just boils down to that, really.

HEATHROW DIRECTOR
3rd Apr 2014, 08:54
Presumably there was no radar?

JeroenC
3rd Apr 2014, 09:33
Tnx all for the replies. There was radar. Can't remember, either south France or north Spain.
"Longest to go" sounds reasonable.

kcockayne
3rd Apr 2014, 10:12
Just the controller trying to do his best....as he saw it. no particular "Rules" involved.

Hotel Tango
3rd Apr 2014, 13:23
Longest to go stays at assigned FL was the general rule at my unit, unless it could be resolved with radar vectors (which for a number of different reasons is not always possible).

Loki
3rd Apr 2014, 14:55
Well, quite. On the face of it, it seems a kack handed way to solve the problem....but who knows what constraints the controller was operating under?

Plazbot
3rd Apr 2014, 15:41
I once had a scenario where a number of aircraft were converging on a point to all join the same route. The last to reach the point was penalised somewhere around 6000ft as they were all hitting oceanic airspace. The penalised aircraft protested loudly as they believed the had right of way as they were the first on the airway as the merge point continued as their current airway and none of the others did. There was no other option that could be solved with speed matching pairs. Two way route so Non Standard not available. :ugh:

jmmoric
3rd Apr 2014, 17:46
Item 5.3.3.6:
"In so far practicable, cruising levels of aircraft flying to the same destination shall be assigned in a manner that will be correct for an approach sequence at destination."
Item 5.3.3.7:
"An aircraft at a cruising level shall normally have priority over other aircraft requesting that cruising level. When two or more aircraft are at the same cruising level, the preceeding aircraft shall normally have priority."

I am sure most controllers would use vectors to handle crossing traffic, if they have radar that is, but there are lots of situations where it's easier to change levels, could be there's no room for vectoring, trafficload, no radar and so on.

On the beach
3rd Apr 2014, 22:07
An upgrade on a triple 7 trumps an "upgrade" on a 73, specially on an 8 hour + sector! Rule of the jungle. :)

Una Due Tfc
4th Apr 2014, 21:04
Don't inconvenience a heavy if you can avoid it