Co-ordination under a Traffic Service

[bookworm]

I gave Brize Radar a nasty surprise yesterday by changing level by 500 ft under a Traffic Service without notifying in advance. I think it was a particular issue because, as we soon found out, the intention was to coordinate us against another aircraft inbound to Brize.

Undeniably my bad in this case, but it made me wonder if those of you working ATSOCAS routinely coordinate against aircraft on a Traffic Service without advising the pilot of the coordination.

[Glamdring]

You should have notified ATC of your level change. The ATC also should have advised you of the co-ordination. Phraseology along the lines of "G-PV, Request not above altitude 4000 feet, for co-ordination".

[ADIS5000]

bookworm,

As you appear to understand; "... a pilot shall not change level or level band without first advising and obtaining a response from the controller, as the aircraft may be co-ordinated ... without recourse to the pilot." (Traffic Service, MATS Part1 and CAP 774.

However, I've yet to meet anyone who doesn't ask or advise the pilot about the co-ordination before imposing it. Technically Brize didn't do anything wrong though.

Regards, ADIS

[GBOACdave]

but it made me wonder if those of you working ATSOCAS routinely coordinate against aircraft on a Traffic Service without advising the pilot of the coordination.

Bookworm,

As someone who works ATSOCAS regularly, I will often coordinate aircraft working under a TS on my frequency against other Deconfliction Service traffic without immediately telling the pilot. However, I will always tell the pilot about the coordinated traffic when the aircraft in question is between 5 and 10 miles away.

If it is quiet enugh to do so (and this may not always be apparrent on the frequency), then I'll do my best to inform the TS pilot nice and early to ensure that they are aware of the coordination in plenty of time. The last thing I want is the DS aircraft still descending 2000' above a coordinated TS aircraft, and the TS aircraft getting concerned on TCAS and taking avoiding action of their own.

Hope this helps

Dave

[bookworm]

Thanks all.

It was exactly the "without recourse to the pilot" wording in CAP774 that surprised me and prompted the post. I'm pleased that the consensus seems to be warning of the coordination if possible -- it makes sense from the pilot's perspective for planning. But for all I know, Brize was just about to tell me about the coordination when he noticed the change in level.

Anyway, useful lesson learnt for me.

[chevvron]

I always used to say 'advise any change of altitude' if it was likely a transit might be co-ordinated against other traffic, but as I don't do radar anymore, who am I to comment?.