As a fairly new JAA-PPL holder who has learnt to fly in the US, I was a bit overwhelmed when I first saw a VFR chart of Southern England and tried to plan a route around London.

The London TMA took an unwieldly complex shape, was split into dozens of irregularly shaped sub-sections, and was Class A. Whereas equivalent busy airports in the US had a much simpler, Class B inverted wedding cake structure.

Being curious, and having found nothing on Google, I wrote to CAA's Controlled Airspace section to see what they had to say about the London TMA, specifically:
1) Whether it could be made class B to permit VFR flying, and
2) Whether it could take on a more simpler, regular shape

Their reply was as follows:

Both the US and UK have developed their airspace structures to suit their operational requirements. In the UK FIR we've tried to minimise, as far as practicable, the volume of airspace classified as controlled; consequently it is intensively utilised. Because of this intensity of use it has never been considered appropriate to allow mixed IFR / VFR operations.

I then asked what these key operational differences were, and mentioned that VFR route planning wasn't very friendly for the average PPL pilot due to such irregularly shaped chunks, citing an example off the AIP's 6.1.4.1 ENR chart of controlled airspace.

Their response was as follows:


[The US has] several great advantages over the UK; space and number of runways.

Space. The US are able to make far more effective use of their Air Route Traffic Control Centers (ARTCC) - known as Area Control Centres (ACC) in the UK - by preparing arrival sequences of traffic before they enter into the TRACON area of responsibility. They can set these up hundreds of miles out applying level or speed restrictions as required; the distances available to them make these measures very effective. Having your arriving traffic sorted out before it enters the TMA reduces the complexity significantly, enabling a degree of systemisation to be applied, reducing workload, enabling you to handle more traffic.

Number of runways. Due to the number of runways available to US Controllers they are better able resolve potential airborne departure interactions whilst the aircraft are still on the ground; additionally arriving aircraft can be vectored towards the nearest available runway to the TMA entry point, thus eliminating some crossing conflictions. In the London region most airports are single runway operations or they are operated in Segregated Mode (as opposed to Mixed Mode where either runway can be used for both arrivals and departures); this tends to lead to a design of complex converging / crossing SIDS and STARS in order that aircraft can arrive at or depart from all runways. This complexity leads to a heavy reliance on controller interaction with aircraft consequently reducing the number of aircraft that can be moved safely through the airspace.

Consequently they're able to reduce the size of their TMAs (even though they can process more aircraft through it) and have more simplistic airspace structures.

I can't deny that the airspace design around the LTMA has become quite complex and it is something that the airspace designers are now actively focusing on. It is certainly a factor been taken into account for any potential re-design of the LTMA. In places the way the airspace evolved the base levels are perhaps overly complex because of a desire to leave as much as airspace as possible Class G.

Because of the concentration of traffic the service providers have been able to match the available controlling resource to the primary IFR traffic flows; leaving little capacity for talking to other traffic - unless it has some sort of priority requirement.


I hope they could revisit the design of the LTMA and other parts of CAS with more regular shapes. That might mean the volume of CAS would be increased, but plotting a route would be easier and could lead to less risk of infringements. Also having more pilots talk to more controllers could provide greater safety for everyone else.

With Eurocontrol's Single European Sky, this could mean European upper airspace would be given to area controllers to sort aircraft out before entering the TMAs.

I wonder if anyone else shares similar views as myself.

Flying amongst the big jets in Class B airspace in the USA has certainly been an exciting and unforgettable experience.

As a fairly new JAA-PPL holder who has learnt to fly in the US.....

Mad Stuff

.....I wonder if anyone else shares similar views as myself.

Not really.

I suspect that had you done your JAR-PPL in Arizona, and suddenly been confronted with a CAA Scotland 1:500K chart, you'd also be calling for the terrain to be levelled to something you'd be happier with.

I further suspect that you're either trolling, or on drugs, or both.

However, if you think UK airspace is a tad leary for ex-US JAR ab-initios, then this little gem recently posted on the Other Place (and probably here) should get you convulsing nicely:

http://i101.photobucket.com/albums/m74/peterh337/jepp-joke.jpg

Avoid Italy..and the Swiss.

I suspect that had you done your JAR-PPL in Arizona, and suddenly been confronted with a CAA Scotland 1:500K chart, you'd also be calling for the terrain to be levelled to something you'd be happier with.

What an idiotic comment. Fuzzy asks a very valid question, and the CAA answer is quite instructive, although it doesn't really answer the question why US controllers (and most continental European ones) can handle VFR traffic as well as IFR traffic in the same environment, whereas the UK ones cannot.

Well said 172 driver, I totally agree! Good questions to the CAA and informative answers.

Perhaps the mix question should be re-asked?

Reply to eHarding:

I agree there's a lot of mountainous terrain in Scotland, but that's what the Maximum Elevation Level figures on the chart is for.

As for the chart below, one might wonder why those three long rectangular blocks of class C aren't merged together as one.

Trying to remain outside CAS to fly between those rectangles (e.g. Ascona to Ambri aerodrome) appears seemingly impossible, if not dangerous.

The good news, unlike the London TMA, is that you can get clearance to transit through the zone if you're flying VFR, and if so, those rectangles effectively disappear from your list of navigation concerns.

UK controlled airspace is quite small and reasonably tightly designed around the SIDs/STARs, approaches, and missed approaches. Hence the shapes look a bit weird. Sure one could make it more regular (e.g. circles like they do in the USA) but the total area of CAS would increase.

I do think it is a bit weird that you can have one bit of CAS with a FL055 base and right next to it you have another bit with a 5500ft base (look just N of Luton for an example). This is a bust looking for a place to happen and is just stupid.

However, the USA also has a lot more of a "can-do" attitude with less anally retentive practices. Their system is more connected-up.

I don't think UK airspace is complicated - one just has to read the chart. I did my IR in Arizona and while one doesn't need to worry about CAS when flying IFR (out there) the VFR charts did look as unfamiliar to me as the UK ones look to somebody from over there. One has to read the chart, that's all. At least the UK ones have no implied airspace like e.g. the 1200ft Class E base in the USA (IIRC) which is not shown explicitly on their VFR charts. On the CAA chart, what you see labelled is what you get.

That piece of a Swiss chart was originally posted by me. It is total crap and incomprensible. However, someone posted that it is actually wrong! In which case somebody ought to tell Jeppesen (the designers and publishers). It has been like that for a few years at least. I flew there VFR (2004 and 2005) and flew at FL129 to stay below the Class C which the Swiss would not let me into. I don't think Jepp charts are very clear in places, but they are the only game in town for much of Europe, and outside their coverage area things only get worse, with the 1990s (obsolete) U.S. ONC charts being the only option. Nowadays I would go through all that crap IFR and the airspace class becomes irrelevant... FL160 plus.

If, as a newly qualified PPL you thnk the CAA will alter the layout of the London TMA to suit you, because you find it difficult...

You have perhaps chosen the wrong pastime, or the wrong place to do it.

As IO540 says, study the chart. The airspace allows you to fly at MSA, 2400', underneath the whole of the TMA. If you stick to that altitude or less until you have got used to the airspace, and navigate accurately, you won't go far wrong.

The good news, unlike the London TMA, is that you can get clearance to transit through the zone if you're flying VFR

Sometimes Heathrow Radar will give you SVFR clearance. I've received that when wishing to transit North - South in the west of the zone in a PA28.

it is a bit weird that you can have one bit of CAS with a FL055 base and right next to it you have another bit with a 5500ft base

Probably something to do with London transition level being FL060 and generally lower elsewhere. A completely barking system if you ask me. Why not a much higher level like the US has (FL180)? Never mind the chance of a CA bust, there is much higher risk of loss of terrain clearance, GPWS warnings etc from the ludicrous method of having TL's below the local MSA in the UK!

Sometimes Heathrow Radar will give you SVFR clearance

Don't think I've ever been turned down by LHR, unlike Stansted & Solent :\

I've attended several ATC training days in a professional pilot capacity and always put forward the suggestion to free up a bit more of the London CTR at the west side (perhaps even a 1500 base to it around the east of White Waltham to let people through without having to call up).

The ASCOT-BUR corridor is so well used, I'm surprised it's not made more formal yet.

Probably something to do with London transition level being FL060 and generally lower elsewhere.
I suspect that you really meant Transition ALTITUDE which is fixed rather than Transition Level which is variable dependent on pressure. The LTMA TA is, of course, 6000 amsl. I agree that the inconsistency of TA in the UK contributes to all sorts of problems such as highlighted and consider it ludicrous that it is below UK's highest MSA, although I think that in view of the UK terrain a common TA of 6000 ft should suffice.

The ASCOT-BUR corridor is so well used, I'm surprised it's not made more formal yet.
Because Standard Separation is required ASC-BUR capacity is basically 'one-at-a-time' and therefore hardly a corridor which could be 'formalised'. It is much to close to ILS profiles and SID profiles for it to be considered as a 'low-level freelane'.

in view of the UK terrain a common TA of 6000 ft should suffice

Even better, how about 10,000 feet then it's above all our MSA's and almost every GA flight need not be concerned about flying flight levels?

There is a lot of work being done in europe about getting a common TA/TL.
The Nordic countries is being used as a test case for a common 10K, 12K or 18K TA.

Not easy mind you, everyone thinks they need something special.....my own employer included. :ugh:

One of the reasons for the irregular shape is that they are designed as polygons which fit perfectly together with the UK airways.

Of course, the UK airways themselves are oddly shaped, with the centreline sometimes not being in the centre, the width changing from one reporting point to the next, and odd little sections of airspace which are declared part of an airway for no reason other than to fill in the few gaps that would otherwise exist between them!

I applaud the original poster's initiative in actually writing to the CAA about it, and I was interested to read their response.

I have too agree. Fair play to the original poster, Sometimes it takes a fresh pair of eyes and an enquiring mind too, to ask the obvious question.

Now prompted, have a look at the Gatwick Zone and drop it over Manchester. 2 similar capacity airports but one seems to have needed more airspace for about 46 years:confused:

Sir George Cayley

There is actually a logic to the funny shaped bits of airspace. Certainly at places like LHR and LGW the airspace became that shape as a result of aircraft performance and turn radius during departures and arrivals. The controlled airspace is there to protect separation of IFR traffic.

If you go back some years and look at an old chart you'll notice the size of the LHR TMA was significantly bigger. The reason it shrunk? Aircraft performance has improved. Engines are more powerful and can deliver better climb rates. This was good news if you happen to fly GA from EGLM. No longer having to channel down the narrow corridor over the railway line, you can now approach EGLM from the north and south (ok, east to if you're on an SVFR).

Other bits of airspace have been given back too. Remember Upper Hayford?

The UK airspace is a compromise. NATS try to give the GA community as much class G to play with as possible and still offer folk suitable IFR protection. It may appear eccentric and unnecessarily complex to a foreigner, especially one who has been spoilt for space and flexibility. I'd suggest it's a good idea to brush up the VFR nav when flying in the UK for the first time. Rather than have an embarrassing zone bust and groveling phone call.

Would anyone be interested in a visit to Swanwick for a talk about airspace and infringments etc etc?

I can sort one out if there is enough interest for this.

Yes, please. Chris N.

Visit to Swanwick?? You bet - count me in. What a superb opportunity for some really productive understanding. My passport and second form of photo ID is ready and waiting!

P&H

I'd be interested in a visit too :ok:

I would be extremely interested!

count me in

Me too :ok:

Me too please :)

Would love to visit Swanwick !! Count me in..

Me too, sign me up.... :ok:

BRL,

Please pencil me in for any prospective visit!

Thanks :)

If I can I ll be there!

and if you extended this invite to the clubs around greater London you'd end up with a serious traffic jam!

I'd also love to visit - count me in please. Would be very informative.

Paul.

The LTMA is not that complicated, what is complicated are the charts - or at least the visulisation of them. We flew over Phoenix the other day which has some pretty complicated airspace but there are two distinct differences...1) They produce a VFR terminal chart of the area, and 2) The CAS stops at 9000'. In the UK they got carried away with making airways class A which causes no end of trouble / busts and probably for not much good either. If for example airways were not class A but class E (controlled for IFR flight) , then one could fly right over the top of say Southampton at FL060 and so would never have to ask for a transit. This is the US and many european county's model.

Any news on the Visit to Swanwick?

I am just going to get new year out the way then I will sort it out early January.