UK Transition Altitude 18,000ft

[Neptune262]

http://www.caa.co.uk/docs/2257/20120131HarmonisedTAConsultationDocument.pdf

What are the thoughts - good or bad idea?

[Cough]

Fan in some respects, but not others.

I imagine freq congestion is going to soar as repetitive Readbacks of the QNH, and large altitude clearances are going to get in the way of controlling. But there will be less chance of screwing up a sim check due forgetting to set QNH on a single engine!

Time will tell

[chevvron]

Mods: already a thread running in Flight Deck Forums.

[Neptune262]

Chevron - agreed, but as an ATCO I tend to only read this forum. Also I would have thought that other ATCOs would like to talk about this subject.

We have a lot of USA ATCOs reading this, who can contribute from their side, where this is the norm.

I can imagine some flights/airspaces which presently cruise/use FL180 / FL190 in the UK may have issues.

Mods - please keep this open for valid ATC comment, however if common consensus is this thread is not required, then please delete it.

[chevvron]

It's duplicated in Private Flying too. I think it would be beneficial to merge all three into one so we can all see the others' views.

[5milesbaby]

Neptune262 - NATS have been working on this for 2 years now including the implementation problems including the likelihood that the Irish will be the only FIR to transition at the same time. It is coming in like it or not, and eventually it will be the whole of Europe using the same TA. Shame it isn't the same as the Americans use to avoid any more confusion after a long transatlantic flight....... :ugh:

[landedoutagain]

My thoughts, its a not a great idea.

It has some merits, but the thought processes about what they are trying to acheive are all wrong, and as such its going to cost ATC providers (certainly in the UK) a small fortune to implement. The same end result is acheivable without mass airspace change, and hence at a much lower cost. As usual though, those high up don't listen to anything from those who actually work aircraft, and who are best positioned to comment on such things.

It seems like they have seen a solution and are too blind to consider that there are much better ones out there.

[10 DME ARC]

i have worked in UK 3000ft and then 6000ft (CTR/A only) and now work in DXB where TA is 13000ft and TL FL150, higher the better for an Approach radar controller, every one on same setting. 2000ft is a good buffer which over here works fine but could occasionly not work in UK, but would reduce thinking/working out?

[Conspiracy Theories]

I'm not sure if this is the correct thing to do. The whole idea is that the aircraft can climb to a higher altitude under the stacks and therefore get higher quicker and save on fuel. The problem is that less aircraft will hold close in which then means that inbounds will hold further out and cause delays for outbounds from other countries (EHAM/EBBR/etc) because we cannot accomodate the extra traffic coz we are holding enroute.
I'm not against it but there are so many problems to resolve and i'm sure it will be introduced in a workable format that isn't entirely "safe".
The amount of RT will go through the roof not to mention the new phraseology for the guys/girls in Area control.
Aircraft that cruise at FL180/190.....well they will not be able to cruise at those levels anymore and the majority of UK airspace, there is a few airspace divisions at those levels which means that there will be more aircraft level capped.....i mean, is it really worth the extra fuel and delays to get aircraft off the deck quicker to save.......as the title states......i'm not entirely convinced (yet).

[Not Long Now]

"The whole idea is that the aircraft can climb to a higher altitude under the stacks and therefore get higher quicker and save on fuel."
What??

[ZOOKER]

It seems possible that someone cruising at FL180, (sorry 18,000 ft), from EGHI to EGPF, may have to set about 6 different QNH values.
This is like the introduction of ORCAM, only in reverse. :uhoh:
At least the a/c won't hit Mont Blanc. :ok:

[HEATHROW DIRECTOR]

Can someone tell me any benefit? I should have thought a single altimeter change on arrival and a single altimeter change on departure was a good idea. Pilots often complain about workload so what happens when they have half a dozen pressure changes to cope with?

[Wonkavater]

If this was part of a push for a world-wide standard, then it would perhaps be a good idea. Seven thousand feet being mistaken for ten thousand feet on the R/T is one of the many phraseology pitfalls. For my own peace of mind I find myself double stating all 5 figure altitudes ("climb to one-two, twelve thousand feet"). I do agree with 10 DME ARC though, having a transition layer of 1500 feet plus takes the mental gymnastics out of work things out when the pressure is low.

[Nimmer]

The long term plan for the london TMA is to move the stacks further away from the airports.

The outbounds will get an unrestricted climb to at least 10,000ft. Having a TA of 18,000ft means there are more levels available for departures, especially at airports that are close together. Thus crossing tracks will be at 7/8/9 thousand feet instead of 3/4 and it should mean all airports will have freeflow on deaprtures as more levels can be issued on SIDS.

All european countries are keen on the change except the FRENCH, and it was origionally their idea!!!!

I am sure Area controllers are intelligent and sharp enough to work in altitudes aswell as FL, after all the TMA have been doing it for years!!!!

[Blockla]

Pilots often complain about workload so what happens when they have half a dozen pressure changes to cope with? Most pilots will have one pressure setting to change, if you never get above the transition altitude then you may need to change, but a differential of 5hpa is considered to be irrelevant for enroute flight; so you actually only need to change when the pressure setting is greater than 5hpa from the original setting, you get aerodrome QNH from approach/tower/atis at destination. In Oz we use 'area QNHs' these are geographic areas of a couple hundred by couple of hundred miles. Sometimes there are multiple area QNH's for a particular QNH area, such as when a deep pressure front or tight low pressure system moves through. These are issued in a similar format to sigmets and are easy to read.

Personally I think it's a good thing to have a consistent base whatever you pick, FL180, is a good start and probably will help harmonize another aviation quirk. I Wonder if Oz will head that way too?

Wun Zero Thousand = A100. It is never confused with A070...

[soaringhigh650]

The long term plan for the london TMA is to move the stacks further away from the airports.

Or ideally ensure they are never used routinely and start applying speed restrictions and prepare for CDA many hundreds of miles out.

[Gonzo]

Continuous climb gives you significantly more environmental benefits then CDAs, so the airspace will be set up to facilitate it.

[Not Long Now]

Unfortunately, many hundreds of miles out puts you in France, Germany, Holland or Belgium, and getting them to start the LL APC sequencing is generally met with "non".

[soaringhigh650]

FAB (http://www.skybrary.aero/index.php/Functional_Airspace_Block_(FAB)) ulous.

[The Many Tentacles]

As someone who works Area in the UK, I think it's amazingly stupid. Given the amount of points that we have introduced to allow level by restrictions without a distance before a certain point, e.g. level BEDEK instead of 40 before OCK, and the number of airlines reporting their STAR on first contact to reduce RT congestion, I fail to see how telling every aircraft the QNH will help matters.

Given that our radars can only show flight levels, i.e. something at 6000 ft might well show 6,200 on the radar isn't going to help either, unless some clever sod has thought about how to filter that.

I can't see the benefit, I know a few American carriers report climbing/descending to an altitude, but they are so few and far between and it only takes a second to clarify.

As far as I can see, it's someone in an office somewhere who is trying to keep themselves in a job, god knows there's enough of them knocking about in aviation

[chevvron]

I don't know what radar's you're using, but all the NATS radars I've used for 34 years are configured to show altitudes below the TA and FLs above it, so where's the problem?
We used to have one system at my unit which was configured to accept different QNH values where necessary ie observed QNH under the TMA with TA 6000ft and RPS outside it with TA 3000ft.

[Not Long Now]

I think you'll find that someone has to pass the QNH eventually, it's just it may well now be you rather than TC or APC.

[Talkdownman]

Given that our radars can only show flight levels, i.e. something at 6000 ft might well show 6,200 on the radar isn't going to help either, unless some clever sod has thought about how to filter that.
Easy. Get Tels to input the new TA into the RDPS.

[5milesbaby]

Not Long Now - all those countries don't need to say "oui", it is being considered for the messages to be sent directly to the cockpit, and a reduction doesn't necessarily need to be agreed by ATC. I hope good airmanship will rule and if flying free speed ATC will be informed if a change is requested, but in a world where an A320 can be flying anything between .70 and .80, is that a necessity? Fair enough, if a speed is already applied then any change will have to be requested and then that "non" could probably appear.

I would be very surprised if Scottish Area don't have altitude conversion on the radar, all the AC radars further south do. Can't think of where else you may be providing Area control in the UK TMT?? You may think it is "amazingly stupid" and that "its someone in an office somewhere who is trying to keep themselves in a job" but read Nimmer's post, Soringhigh360's first one and Gonzo's contribution, put them all together and you may start to understand why this, or something similar, will be implemented within the next 2 to 3 years.

I would be interested to see any research on how the additional RTF in AC would impact certain sectors, and best not start the debate on how it is to be recorded!

[babotika]

Call me crazy but wouldn't the lowest possible TA be more sensible? Platform altitude a-la Paris/Amsterdam/Frankfurt/etc with all SIDs climbing to FLs. Would mean no QNH change on departure (1013 before leaving the ground) and only one at the very end with very little chance of it changing before landing. All this talk about continuous climbs is complete nonsense, that depends entirely on airspace design and atco brain power.

Terrain avoidance is much less of an issue now than it was in the past, standby altimeters set to QNH permanently combined with ATC seem to look after it well enough.

Posts this in the wrong forum originally, apologies if it looks familiar.

[Captain Smithy]

Not convinced myself, advantages and disadvantages I think, personally a TA of 10000' would be more sensible.

The Many Tentacles - the reason your Radar shows FLs is because Mode C/Mode S output is pressure alt, 1013mb/hPa/whatever the Europeans change it to next week for the hell of it. Thought you'd know that :=

Smithy

[ROBSAUSTINHEALEY]

Its even got the wrong name! MATS Pt 1 still refers to TA being applicable "...in the vicinity of an airfield" or beneath CAS. So, at 18000' over the North Sea, which airfield are you in the vicinity of?

Your turboprop cruising at 17,000' approaches an FIR Boundary - there's something the other side at 18,000 and one at 16,000' on a different QNH; how does the conversation with Paris/Brussels ACC go?

[ZOOKER]

'TCAS RA'. It's a horizontal level-bust. :uhoh:

[10W]

Babotika

From a working ATCO point of view, you are correct.

From an office/empire building/emperor's new clothes/regulator's point of view, you are wrong :)

10.000' is a reasonable compromise. It works with cockpit procedures and most of European ATC. If it doesn't work with future UK plans, then UK plans need to change. Having up to 40 different QNH settings in the UK, each requiring an RT transmission, and read back, is absolutely stupid and will cut capacity significantly because of RT workload. But hey ho, apparently it makes all conflicting traffic disappear and allow SIDs to go straight to 18,000'. AYE .. RIGHT.

Lunatics in charge again.

[Neptune262]

The are some "Challenges" in the CAA doc which make interesting reading, as follows:

a. It is anticipated that there would be increases in more general workload due to a greater requirement to pass QNH values.
b. More altimeter adjustments would give the potential for more mistakes to be made by aircrews in setting the wrong pressure, although the potential error value is lower.
f. A loss of preferred cruising level for some airspace users; the proposal is to remove FL190 as a flight plannable cruising level in all pressure situations.
g. The loss of FLs, on low pressure days, is moved out of the TMA environment to the En-Route environment in the vicinity of FL190
j. There may be capacity penalties within some controlled airspace sectors.

So from the above my questions to fellow ATCOs are; Who works present UK airspace which f. / g. / j. above will affect? What do you see as the operational consequences to this change? What about present airspace with FL195 as the upper limit, what happens there?

Then there is also the below taken from the following website:
Roger-Wilco | Transition altitude (http://www.roger-wilco.net/transition-altitude-%E2%80%93-the-higher-the-better/)

"Is there a problem with the transition altitude?
Well, perhaps you will be surprised to hear that there have been numerous loss of separation incidents, some of them quite serious, in Europe in which altimeter setting errors were found to be major contributing factors.
While the concept and use of the transition altitude may sound simple and straightforward, there are two aspects of the transition altitude as implemented in Europe that harbor the potential for mistakes.
First of all, there is no uniform transition altitude in Europe. Clearly, States with high mountains will always have a different transition altitude from those with no mountains to speak of but even these latter have not come to any kind of agreement as to where the transition altitude should be. Such disparity and eventual uncertainty in the cockpit can easily lead to errors.
Then there is the process of changing the altimeter setting itself. With a transition altitude around 5000 feet, the change has to be made during a phase of the flight that involves high workload, another factor that brings with it the potential for errors.
Taking them together, those two aspects of the altimeter setting procedures do constitute a measurable risk to safety.
What is the solution?
The answer is relatively simple: raise the transition altitude to a higher level, agreed on a European scale, with exceptions only where high terrain makes the commonly agreed level inappropriate.
However, this is easier said than done.
The matter has been on the agenda of various international organizations at least since May 2000 when the Technical Director of the UK Guild of Air Pilots and Air Navigators first raised the subject at EUROCONTROL. A subsequent survey found that there was indeed a wide variation of transition altitudes in Europe and the variations extended even to considerable differences from the applicable ICAO provisions related to the establishment of transition altitudes.
It also became apparent that the specific local interpretation of the transition altitude was used at some places, especially in the military context, as a kind of airspace organization and “default” separation tool and hence any proposal to change it was being opposed not so much on the ground of the transition altitude as such but the impact the change would have on the airspace organization built around it.
As the years dragged on it became increasingly apparent that while raising the transition altitude to around 12,000 feet might be acceptable for some States, having a region-wide practically identical transition altitude was basically out of the question.
However, the nature of the problem is such that only the combination of both raising and harmonizing the transition altitude can bring the desired safety improvement.
New impetus
In the meantime various studies had shown that any raise up to and including 10,000 feet would yield basically no improvement while going to 18,000 feet (as used in the US) would in fact be the most effective solution. This is now also supported by IFALPA as the altitude best meeting the pilots’ needs.
Of course it also became clear that if non-uniform transition altitudes differing from each other by one or two thousand feet were a problem, non-uniform transition altitudes differing from each other by more than 10,000 feet would be an even bigger problem to safety.
While there were States who would have implemented 18,000 feet without delay, they had to hold back because of neighboring States who were reluctant to accept any change.
Getting fed up with the obfuscation, the UK and Ireland, taking advantage of their somewhat “isolated” airspace, decided to unilaterally implement 18,000 feet as the transition altitude starting in 2013.
More recently even the European Commission has joined the fray stating that they considered the time politically and technically ripe for putting an end to the transition altitude saga by implementing a safe solution meeting the industry’s requirements.
The question of transition altitude is on the agenda of most FABs also tough this is a double edged weapon since transition altitude harmonized on the FAB level represents only a half solution, as mentioned earlier.
A solution in sight finally?
All studies performed over the years delivered conclusive evidence that 18,000 feet is a good choice for transition level wherever terrain allows. While the 18,000 feet transition level in the US has not been without incidents, the level of safety demonstrated over there is also convincing. One should also keep in mind that the UK and Ireland must have performed all necessary analyses of the options before coming to their decision to go for 18,000 feet. It is also clear, well, even common sense, that not harmonizing the transition level would only perpetuate a situation that has been shown to be a safety risk.
With the matter once again on the agenda of the appropriate working groups and with the EC also lending its weight to push for a solution it is not unthinkable that a safe and efficient solution will finally be agreed and the matter can be put to rest once and for all."

So I can see the high level pressure being applied to the change.....

[cessnapete]

18000 works well in USA why go for a Europe only 10000.
The QNH 'problem' is a non event in USA with a far greater traffic flow around the busy arports.

[Avoiding_Action]

Why not scrap TA completely in that case? The argument appears to be that flight levels are a waste of time.

[5milesbaby]

cessnapete, as already mentioned, if Europe switch to 18,000ft it means we will not be aligned to the USA/Canada. I know its only 1ft out but in useable levels there will be a 1000ft difference, just think too many people are thinking they will be the same.