3 mile separation

[52 North]

Hi

Expecting a "no" to the following question but would be useful to know:

Are there any units in the UK which have approval to use 3 mile separation between aircraft on different frequencies being worked by different controllers, even when the controllers are not sitting next to eachother?

E.g. are there any TC sectors which have direct intercom instead of sitting next to eachother?

I know the book says you must be sat next to eachother but just wondered if any units had any dispensation.

Thanks

52N

[AlanM]

yes - plenty!

The TMA, London airfields etc.

Even Heathrow and Northolt approach use 3nm (provided the Priority line is serviceable) - and they are two completely separate units.

[52 North]

Alan M

Thanks for that, so I take it that the priority line is a phoneline as opposed to an intercom system. Is it only used when things are going wrong? (or not as planned)

Can you think of any others? Could do with a few examples.

52N

[A I]

Twas many a year ago but didn't there used to be a 3nm buffer between Glasgow and Prestwick. Drawn on both video maps and neither unit was allowed to cross their respective line.

A I

[52 North]

AI

What happened if aircraft did go into the buffer? i.e. RT fail, wx avoidance, traffic avoidance. Was it just a phonecall or was there some sort of priority system?

Thanks

52N

[A I]

Phone call if I remember correctly. Actually, as PK was pretty quiet, an imaginary buffer existed 3nm south of the proper one and PF were allowed to use the buffer as part of their zone/vectoring area. This was 30 years ago!! Like to hear when it all changed.

A I

[AlanM]

Aren't most priority lines used when things don't go as planned!! :)

But yes - they are phone lines not intercom.

When you consider how many sectors there are at TC (TMA and Approach sectors) I think jsut about all use 3nm separation - some sectors are in the room and only have an in internal phone line (I guess you could scream across the room)

Speak to TC Ops about it.

[52 North]

Alan M

Thanks, planning to speak to them shortly.

52N

[MancBoy]

AlanM, I'm sure you're wrong.

In order for TC to use 3 miles they have to have both aircraft on frequency, be below fl245, and be within a specified distance of the radar head ( 80 or 60 miles).

[Jerricho]

.......AND a means of effecting immediate co-ordination if required between non co-located sectors (this is where the priority line come into play)

Hi Al ;)

[AlanM]

MancBoy

Yes - it has to be below FL245 (how much of TC airspace is above that?)

Yes - there are distances from the radar head (60 or 80 nm) that aircraft must be within

No - they don't have to be on the same frequency:

6.3.2 Separation Requirements - Reduced Radar Separation Minima and Northolt RMA:

Subject to the serviceability of the priority telephone line between TC Heathrow and ATC Northolt, 3nm
minimum horizontal radar separation may be applied between all traffic under the control of ATC
Northolt Director and TC Heathrow Directors,

So not only NOT co-located - but RAF JSP v Civvy MATS pt2! But, as said above - the priority line must be serviceable. (Which is why they are checked as part of Northolt opening up procedures)

Even though in the GEN section it says:

under the control of the same controller or co-located controllers with a means of effecting rapid co-ordination

Wotcha Jerr! - Bobby P said he missed you when he was down yr way!

[MancBoy]

alanm, sorry about that, of course you're right.

i was trying to remember it from my days of doing tc north as i don't have access to a tc part 2 at the moment.

[AlanM]

mancboy - confusing isn't it! :)

[ATCOJ30]

Bristol and Cardiff can use 3nm, using a buffer zone delineated on radar displays at each unit or by telephone co-ordination. (below FL245 only!)

[52 North]

"Bristol and Cardiff can use 3nm, using a buffer zone delineated on radar displays at each unit or by telephone co-ordination. (below FL245 only!)"

By telephone coordination do you mean that FF and GD can use 3 mile sep outside the buffer zone? If so do FF and GD have a priority phoneline to eachother?

Thanks

52N

[Pierre Argh]

This may not be relevant to the reason behind the question, but under UK Military ATC regs (if interpretted appropriately) it is possible to reduce separation to 3nms, by letter of agreement (effecting coordination), between traffic working different units, different frequeuncy, based solely on recognition of the other units squawk... but I don't know any that currently do so?

[Aviator 1972]

O Shucks!!!:mad: And to think we get suspended/possibly fired when it comes to 4.9nm's on our App and 9.9nm's on Acc positions??
6 Weeks on the admin/nerve wrecking bench.... lots of counciling etc etc etc.

Hi ATNS read this pse!!!!! (King Athur/Lord Charles/Sir Craig

Why can't we use 3nm seps?? Plenty of radar stations to use.:ok:
Rgs