L9 MEA between Bristol and CPT

[bookworm]

For a flight from Filton to Cambridge this afternoon I filed DCT MALBY L9 KENET LOREL2L STAR (via WCO) at FL70, which seems to get accepted by IFPS and respect the airway MEAs, which rise to FL90 west of MALBY and also east of KENET.

Bristol told me that London required me at FL90 to use the airway, and FL90 wasn't a problem on the day. Is this really the case for a Cambridge (Stansted) STAR or is there just an expectation that L9 eastbound normally overflies the TMA and so requires FL90?

(I appreciate that FL70 is a PITA in the TMA, but unpressurised with icing above there's sometimes no choice.)

[Chilli Monster]

Only a guess (not having worked their a while) but:

1) Standard join out of 'TG' is WOTAN (not MALBY), where FL70 is outside CAS - hence higher level (refer to UK AIP EGTG AD 2.22, also included in AERADs / Jepps )

2) Joining FL70 at Malby puts you in the teeth of 'DL' departures on their SID, hence higher level requirement (and different join point referred to above).

[Scuzi]

FL90 is the notified minimum overflying level in the London TMA, however, on the day if things aren't too tricky we may say yes to lower.

The problem with FL70, especially when you get to between WCO and BKY/CAM is that you're in the teeth of everything. All out outbounds from SS on BUZAD and CPT SID's are transferred to NW Deps on a standing agreement at FL70 when the pressure is high (1013mb+) and FL80 when the pressure is low.

Another thing, if the pressure is low, FL70 isn't separated from 6000ft and the LL WOBUN/BUZAD SID's climb to 6000ft as does the GW OLNEY SID on Rwy 08 and LC BPK and CPT departures are usually coordinated in at 6000ft.

So, as you can see, at those levels you are in the middle of absolutely everything. If it is remotely busy at all you can expect to get told to drop out the bottom if you can't take a higher level or end up getting vectored around the sky. I'll do my best to accommodate you but if the traffic situation is complex (and believe me, it can become VERY complex in that bit of airspace) I'd have to turn you away.

You're more likely to be accepted if you elected to route up towards the DTY direction but I honestly don't know how that would work out from a flight planning point of view.

[bookworm]

Thanks Scuzi, that's just the sort of info that helps.

FL90 is the notified minimum overflying level in the London TMA, however, on the day if things aren't too tricky we may say yes to lower.

Understood. Technically, I'm not overflying the TMA but departing from or arriving at a TMA group airport that shares its STARs with Stansted. But perhaps that makes no difference, as the procedures all assume that arrivals will start well above FL90.

[bookworm]

2) Joining FL70 at Malby puts you in the teeth of 'DL' departures on their SID, hence higher level requirement (and different join point referred to above).

Ah, yes I did see the note and wonder why the standard join was at WOTAN at 90. Since it's initially outside controlled airspace and I wanted the FPL accepted at 70, I chose a different join. Is DL really that busy? Could Bristol coordinate 70 with Lyneham?

[neilmac]

L9 Cpt-wotan

The area around MALBY can get busy with Bristol, Brize and Lyneham using it for SID and STARS around the FL70-80 levels. So FL90 eastbound from WOTAN technically subject to traffic you would be above their SIDS/STARS ie: Bristol inbounds need to be at FL80 AT POMAX, Lyneham SIDs FL70 at MALBY and Brize similiar. Of course this is also subject to Sector 23 traffic and not to mention CAS leavers/joiners from Gloucester and Kemble. Co-ordination outside the published procedures are subject to traffic levels and controllers workload, Bristol ATC i know had a few aircraft on yesterday avoiding weather so maybe they were busy, they are always helpful.
Hope this helps answer your question.

NM

[bookworm]

Co-ordination outside the published procedures are subject to traffic levels and controllers workload, Bristol ATC i know had a few aircraft on yesterday avoiding weather so maybe they were busy, they are always helpful.

They were indeed helpful, though they didn't sound very busy (for what RT silence is worth in assessing that) and after a brief time on vectors to the north they pointed me at MALBY with a clearance to join on track MALBY in the climb. So I don't think the actual occupancy of the lower part of L9 was a problem yesterday, though it's helpful to understand the constraints and limitations even so, thank you.

Thanks for all the replies, including by PM. It's all helpful.

[Standard Noise]

If you're joining at Wotan from Filton or Briss, standard join level is actually 100 to be 90 or above by Wotan. If you want a level below the airway then tell Filton, they will get you airborne below L9 up to 70 (during the times that their radar is operational) then co-ordinate onwards with Lyneham. At weekends, we deal with it as Filton seldom have radar then.
Our inbounds from the east don't need to be at 80 at Pomax, that's just the level we can descend them to before Pomax due to the airspace base.

[DFC]

If the flight plan isd accepted by the IFPS then the route and the level are acceptable to ATC.

That is whole reason for having the IFPS in the first place.

If ATC do not want FL70 used on that route they need to tell the IFPS or at least put a zero rate flow restriction at that level.

Otherwise, it is a waste of time having the whole IFPS and CFMU operation if local controllers can set their own personal agenda.

------------

I have once this past year come across a similar situation in the UK - IFPS accpets route, no CTOT but we have an extended delay because London ATC do not like our route. The result was that the company had to ring the IFPS supervisor who had to ring the local supervisor who rang the controller who then suddenly cleared us. It was not a level issue but a routing issue but the primciple is the same.

Regards,

DFC

[bookworm]

I have some sympathy for that point of view, DFC, but the UK is quite generous with DCTs at any level, so one can get some outrageous routes in the TMA accepted by IFPS. I don't doubt that all the controllers I talked to would have found a constructive way of accommodating my operational needs.

[DFC]

There is little point in being generous with direct routes on paper (in the IFPS system) if they are not provided or not suitable in reality.

The point remains that if your get an ACK for your flight plan then it meets the requirements of ATC and if no CTOT then there should not be any serious delay in providing what you asked to do.

To add to the point, the LOREL 2M arrival specifically provides for flights at FL80 or below.

Not a good situation to design a STAR for a level that puts aircraft on that STAR straight into the teeth of departures and mucks up standing agreements.

I wonder what the delay would have been if you were unable to accept FL90 on the day or what would happen with a Radio Failure situation?

Regards,

DFC

[bookworm]

To add to the point, the LOREL 2M arrival specifically provides for flights at FL80 or below.

Not a good situation to design a STAR for a level that puts aircraft on that STAR straight into the teeth of departures and mucks up standing agreements.

Though I hate to admit it to someone with such sharp teeth as yours, DFC , I'm a little embarrassed that I didn't see and comment on the LOREL2M. If it's there specifically for arrivals at or below FL80, it seems absurd that it cannot be used. Should it be withdrawn.

I wonder what the delay would have been if you were unable to accept FL90 on the day or what would happen with a Radio Failure situation?

On the day, that was easy. My flight originated outside controlled airspace. Clearance to join controlled airspace was at FL90. The option was to accept it, or route outside controlled airspace (which was feasible but potentially less comfortable) to my destination.

Nevertheless, I agree that clearances must be flyable, and where a FPL route implicitly makes up part of such a clearance, the same applies.

[Cartman's Twin]

Evening Bookworm.

Just a quick comment in addition to the above. I work the TC South side which you would have entered about 10 miles before CPT. I note that others have noted that the EGLL SIDs climb to 6000' and depending on the pressure FL70 may not be separated.

A further complication is that in this area Southampton departures have to climb to FL70 (to stay inside CAS after departure), and Luton departures have a 'Min Stack' standing agreement (usually FL70 or 80 (and yes exceptionally, like this week, FL90 - but that only happens about once a year)) so FL90 is the lowest level that can be accepted 99% of the time without a disproportionate impact upon normal operations.

I can see your point about the low level STAR but it can still have a use. If traffic levels are low (an increasingly rare event) then you are likely to be accommodated at FL80 or possibly FL70. Also if a special flight with a high category is filing that route then you can, and will, place restrictions on 'normal' commercial traffic to allow for the single plane.

I hope this helps but feel free to PM me for further discussion if you like.

[PPRuNe Radar]

If the flight plan isd accepted by the IFPS then the route and the level are acceptable to ATC.

That is whole reason for having the IFPS in the first place.

Actually it's not the reason for having IFPS in the first place, it's a side benefit. The 'whole reason' is to provide an integrated and centralised processing system for the IFP Zone.

IFPS does not necessarily provide cast iron confirmation that a route is 100% correct or acceptable to ATC on the day. For example, from the IFPS User Manual:

The United Kingdom and Ireland's Standard Route Document (SRD) is
produced by NATS to assist Aircraft Operators in constructing RAD-compliant
route portions within UK and Irish airspace. The SRD is not a mandatory
document, and the routes contained within should be considered as
preferred routings only. The routes are promulgated to identify optimum
routings for operators with due regard to ATFCM requirements. The IFPS is
not obliged to comply with the SRD, and when processing messages, the IFPS
staff shall only validate messages in accordance with current and relevant
RAD restrictions.

There are also known problems with IFPS regarding operators filing on CDRs, for example.

It's a pretty good system and getting better but still has a bit of scope for improvement. Operators doing their homework and getting it right in the first place can greatly assist (not necessarily pointing the finger at the topic of this thread).

While one of the tasks of the IFPS is to provide flight planning assistance in finding correct routes where genuinely needed, message originators are also required to take responsibility for the quality of any messages they shall send to the IFPS for processing.

Of course ATC agencies can play their part too by ensuring that the mandatory use of routes are put in place by their national authority, and ensuring that IFPS subsequently has these contained in it's environment database.

[WildWesterner]

Right back at the start bookworm said "Bristol told me that London required me at FL90 to use the airway", which would have been AC, S23. Unfortunately (and I speak as one of them) I doubt anyone would consider the TMA min overflying level before authorising departure/issuing clearance. In fact the immediate information is not to hand on sector, unless its self-calculated.

Not-withstanding those TC factors if it fitted on S23 you'd probably have been given it and amended later if TC required. I wasn't there but most likely one of the aforementioned Lyneham departures probably got on request first. They join in a holding pattern SIREN, near MALBY, and keep circling till we can take them out. So L9 is completely blocked there.

Hopefully you would have had the option - If Lyneham on request first, no CTOT, then its first come first served and you can either wait till he's up and out of the level, or you can accept a higher level (Level by Wotan) to give clearance procedurally. This is even more likely if a trainee was on, keeping it watertight - as they are taught. Murphy's law says if we gave it to you both, both would be airborne simulteaneously and one would RT fail (I know, I know, the chances are tiny but nevertheless fail safe etc. etc.) In this scenario we would in fact be trying to help you get airborne quicker.

Probably just a case of unlucky circumstances - DL on request before you (there's plenty of DL and Brize traffic with our boys out in the Mideast).

As a side note, I've never used a LOREL2M in anger!!

WW

[bookworm]

Thanks for continuing the discussion, which I hope is useful -- certainly for me.

I note that others have noted that the EGLL SIDs climb to 6000' and depending on the pressure FL70 may not be separated.

Indeed this was one of those days last week where 6000 ' and FL70 were virtually coincident (QNH 987). We didn't discuss if FL80 was available eastbound as FL90 turned out fine on the day.

Actually it's not the reason for having IFPS in the first place, it's a side benefit.

But it is the reason for having FPLs, airways, MEA and the RAD. It's important that operators have a good idea before flight of the routes that are and are not acceptable to ATC. Otherwise, we may end up making assumptions that get us into trouble. It's a great deal easier to know that FL70 is not available in advance on the ground rather than in the climb in potentially icing conditions having already selected the fuel load. There will always be the need for flexibility, but the closer we can get a correspondence between flight planning and real routings and levels the safer it is. Which is one of my motivations for asking what the practical limits are.

Unfortunately (and I speak as one of them) I doubt anyone would consider the TMA min overflying level before authorising departure/issuing clearance. In fact the immediate information is not to hand on sector, unless its self-calculated.

Strange then. I can't see how Lyneham traffic would have been relevant to the choice of level. Bristol cleared me to join in the climb to FL90 on track MALBY (and with a 50 knot westerly I'm not sure I made 90 by MALBY) and implied that the unavailability of FL70 was at London's request.