Deconfliction Service in Class C Airspace?

[ATCO Tree]

A question for UK Area controllers:

Recently, there has been a trend developing of area controllers providing Deconfliction Service to aircraft “below FL245” over the North Sea “due to military activity”. As all UK airspace above FL195 is still notified as Class C, it is my understanding from the UK AIP that the only ATC service provided in Class C airspace is Radar Control Service as VFR still has to be separated from IFR.

With this in mind, has there been some form of change to the classification of certain parts of airspace over the North Sea, altering the base level of Class C to FL245 in these areas, or has there been a national change to the way services are provided inside controlled airspace in relation to military activity that has not been widely promulgated?

Thanks for your thoughts.

[PPRuNeUser0130]

"North Sea Reduced Coordination Area"
Within Cotrolled Airpsace at all levels, inclusive of FL 195 to FL 245, except during periods of notified activation of TRA 5, 6, 7A, 7B.Note 1: Within active TRA lower limit is raised to FL 245.

UK AIP ENR 2.2 section 6 (https://www.aurora.nats.co.uk/htmlAIP/Publications/2019-08-15-AIRAC/html/index-en-GB.html)

[The Fat Controller]

There are TRAs all over the UK and during their various active hours, between FL195 and FL245, radar control service is not provided.

It is very confusing for pilots who are not familiar with the airspace.

[1985]

In London airspace, In the North Sea sector (that controls a tiny bit of the airspace over the North Sea), I haven't seen or heard of anyone doing this.

The North Sea Reduced Coordination Area is designed to allow GAT to be sent direct as much as possible when the D323 complex is inactive with the responsibility of coordination between the Mil and civil controllers falling on the Mil. It is also important to remember that it only applies to a small proportion of the the North Sea.

​​​​During published hours of activity of the TRAs it applies from FL245 upwards and outside of those hours FL195 upwards. Maybe during the hours of activity the controller(s) is using the phrase "due to military activity" as an easy way to explain why a DS is being given. I would expect you to get to get a RCS above FL195 within the TRAs when they are not active ie the weekends and after 1700 local. You certainly would in London.

As Scottish controls the vast majority of the north sea and I don't work there then I can't speak for them as to if and why this maybe happening. There maybe some reason for it that I am not aware of.

[NorthSouth]

It's not about reduced co-ordination, it's solely about provision of ATS inside active Temporary Reserved Airspace, which is only between FL195 and FL245.

[ATCO Tree]

Thanks for all of the replies.

I had not appreciated that an active TRA raised the base of Class C from FL195 to FL245 and so thanks for the steer. It seems that the way in which the AIP and the NATS website describes current airspace classification and structure in the UK is rather disjointed which does not help with the understanding of those flying through it. It’s perhaps no wonder that overseas crews are bemused and confused by the whole thing when flying to/over the UK.

Cheers!

[The Fat Controller]

One of the main problems is that airlines are still allowed to file Upper Air Routes which do not have any Airways beneath them.

That often means descending into active TRAs if they want to follow a normal profile and are able to accept UK FIS.

Some could not accept Traffic Service when Deconflction was not available, so had to stay at FL250 until the TMA or nearest Airway.

For those of you in the front seats, please remember that under either Deconfliction or Traffic Service, it is you that is ultimately responsible for avoiding other aircraft although ATC will do their utmost to assist.

Trying to explain all the idiosyncrasies of the UK TRAs and services available in a dynamic ATC environment was a real pain, I am glad to be retired !

[NorthSouth]

Originally Posted by ATCO Tree

I had not appreciated that an active TRA raised the base of Class C from FL195 to FL245

It doesn't! Active TRAs remain Class C, but they have different rules in order to allow autonomous VFR flight by (mainly) military aircraft.

Originally Posted by ATCO Tree

It seems that the way in which the AIP and the NATS website describes current airspace classification and structure in the UK is rather disjointed which does not help with the understanding of those flying through it. It’s perhaps no wonder that overseas crews are bemused and confused by the whole thing when flying to/over the UK.

Here's how the AIP describes it, at ENR 1.1 para 5.1.5.1.2:
In complying with the EC Regulation lowering Class C Airspace to FL 195, Temporary Reserved Areas (TRA) between FL 195 and FL 245 have been established to accommodate the various VFR UK airspace users including military autonomous operational requirements above FL 195. TRAs may be used simultaneously by both civil and military aircraft, including aircraft in en-route transit through a TRA. Operations will be conducted in accordance with the Rules of the Air, or as agreed via the Unusual Aerial Activities regulations, and required equipment carriage and operation. Although the background classification between FL 195 and FL 245 within UK airspace is Class C, to avoid operational restrictions, military aircraft may operate autonomously or be in receipt of an ATS from approved ATS units within a TRA. ATS in TRAs will be provided in accordance with the UK Flight Information Services (UK FIS).

[ATCO Tree]

Fudge-tastic!

Thanks again NorthSouth.

Originally Posted by NorthSouth

It doesn't! Active TRAs remain Class C, but they have different rules in order to allow autonomous VFR flight by (mainly) military aircraft.

Brilliant! So it is Class C, but effectively becomes Class E/G during notified times, and "reverts" to Class C when not active, but is, at all times, officially Class C controlled airspace............

Originally Posted by NorthSouth

Here's how the AIP describes it, at ENR 1.1 para 5.1.5.1.2:
In complying with the EC Regulation lowering Class C Airspace to FL 195, Temporary Reserved Areas (TRA) between FL 195 and FL 245 have been established to accommodate the various VFR UK airspace users including military autonomous operational requirements above FL 195. TRAs may be used simultaneously by both civil and military aircraft, including aircraft in en-route transit through a TRA. Operations will be conducted in accordance with the Rules of the Air, or as agreed via the Unusual Aerial Activities regulations, and required equipment carriage and operation. Although the background classification between FL 195 and FL 245 within UK airspace is Class C, to avoid operational restrictions, military aircraft may operate autonomously or be in receipt of an ATS from approved ATS units within a TRA. ATS in TRAs will be provided in accordance with the UK Flight Information Services (UK FIS).

That, coupled with about 4 or 5 other sections that describe UK airspace structure and use, TRA's and UK ATS/FIS, gives a whole range of information that is contradictory and confusing to the end user. Sounds like a consolidation exercise is required to tie up the disjointed information that is promulgated about such airspace (Including in route planning documents) to ensure that users are being given the full picture rather than leaving front line ATCOs to field the queries on a day to day basis!

I'm sure that the CAA/NATS are all over it though.......

[The Fat Controller]

ATCO Tree, it was CAA/NATS/MIL that came up with this bastardised system when the UK was compelled to make all airspace above FL195 Class C, it was quite a while ago too, around 2007.

TRAs were introduced to allow the military to continue what they needed to do.

ATCOs were briefed comprehensively but the civil pilot community less so and our foreign customers were (mostly) completely bemused by it all, this continues to the present day !