Clyde Tmz
 

SSE - Clyde


A TMZ down to 3,500' over the A74(M) north of Moffat, any comments?
bb

Yeah. Wht not put a large circle around the terminal airspace instead of a small patch here, a small patch there and a small patch here?

Like this

It makes the charts much simpler to read, encourages everyone to leave their transponder on mode-C, and saves people getting busted for errors with navigating around tight spaces in-between multiple TMZs.

Non-transponder equipped aircraft should be able to use these spaces subject to ATC approval.

Interesting AOPA are not on the list of consultees. Why would you consult British Airways? In the USA the first group on the list would be AOPA.

Personally I don't mind, I think TMZs are a good idea and I think there should be one around every main airport that doesn't have CAS.

Might be an idea to read the consultation docs then. This is a temporary TMZ below the Scottish TMA, supposedly to guard against non-transponding traffic infringing the TMA from below, over a planned wind farm, before a new radar is brought in to deal with the effects of the wind farm. Frankly I think this TMZ is a complete waste of time since none of the traffic in this airspace is getting a radar service, all of them are asked to squawk already, and in any case the TMA radar controllers just ignore primary-only radar contacts because they're deemed to be below controlled airspace (Scottish TMA is already transponder-mandatory above 6000ft and of course all IFR traffic is squawking).
NS

So the Luton TMZ was the thin end of the wedge!

Now we have one of the largest most empty pieces of CAS (see the LAA response to the last change) demanding a TMZ is an area where presently there is no transponder requirement - or much prospect of an ATC service.

There does seem to be an unpublished policy to insist on a TMZ under virtually any circumstance where radar 'might' be impaired.

Well, I'm not sure the Luton (actually Stansted) TMZ is relevant because it's permanent. This isn't.

I agree with the first bit but, with the greatest respect to fisbangwollop and his colleagues, there is actually NO prospect of an ATC service because if you try to call one of the Scottish Control frequencies below the TMA, and aren't intending to climb into the TMA, you will be told to call Sc Info who of course are not radar-equipped. Sc Info will then tell you to squawk.

What I don't get is why the current situation, before this wind farm is built, where a non-transponding light aircraft can climb into the TMA in this area and controllers will continue to assume it's remaining below CAS, is deemed acceptable, but a future situation, when the wind farm is built, and non-transponding aircraft still climb into the TMA, is considered unacceptable.

NS

Perhaps a simpler solution would be to move the silly bloody windfarm away from areas where it might/will affect Radar. :rolleyes:

Or just stop throwing huge sums at a technology that seems to produce a very small percentage of power considering the land investment involved.

I expect they will get lots of returns from the wind farm and would like to distinguish between real aeroplanes and clutter from the turbines.

I don't mind, my own personal view is that every aeroplane should have a transponder.

A Nuclear power station would show up as a smaller paint on a PPI or could be easily built elsewhere where it won't interfere, also would provide much more power over a wider area. Much better idea, nay? :suspect:

Smithy

What's a PPI? Why should it be painted?

A PPI is something that controllers stare at all day, and yet another thing we spods must fix from time to time. :suspect:

A "paint" is a target. Movies, dafties etc. tend to use the horrendously naff term "blip" in substitution (up there with cheesy innaccurate crap like "over and out", "roger wilco" etc.) :ugh:

Smithy

Can anyone explain to me why an aeroplane at 3,499' is not a problem to the radar cover but 3,501' would be? i.e. why a cut off at 3,500'
bb

Most likely terrain. Any Primary returns will either be blanked by the Processor (to counter interference from terrain, windfarms etc.) or will be undetected altogether due to the terrain. Perhaps NS or an ATCE/ATCO from the area in question could confirm?

Smithy

They are; the list is not in alphabetic order!

Because NATS wants to have radar cover extending to 2000ft below the base of controlled airspace, to be able to detect potential vertical infringers and/or provide traffic info for anyone descending out of CAS. Base of CAS here is 5500ft.
NS

Does the Primary coverage extend below 3500' in that region? I can't remember what the nearest ENR Radar site is down that way. Lowther hill perhaps?

Lowther coverage is pretty much down to ground level in that area
NS

I see. I didn't realise that.

S

Thanks NorthSouth. Good to know, now if the base of Controlled Airspace was raised to FL75 that would give a 2,000' buffer below and effectively retain the old base....

If the base went up 2,000' would there no longer be a need for the TTMZ?
bb

Correct. Also worth noting that transponders are already mandatory above 6000ft in the TMA
NS

thanks NorthSouth, great relpy. I would prefer to we see the base of airspace raised to FL75 around the wind farm rather than the TTMZ.

When did this happen? Can you give link to the ACP? Does it apply to gliders and hang gliders etc?
bb

I'd rather its dimensions stay as it is because chopping little bits of airspace off here and there, makes the base levels so over complex that people get busted for airspace violations. A weird phenomenon in Europe.

Why not get a clearance and fly inside it instead? It's safer!

Things unfortunately aren't that simple here. Often VFR traffic will be told to remain clear of CAS.

Captain S

soaringhigh650, If pilots are unsure of their nav skills the have the option of staying low and avoiding all airports by 25nm , sort of a ghost map... then they wont infringe. Those who are competent can work to the real map. With sensible devises in the cockpit like seeyou mobile or winpilot airspace infringements are rare.
Naviter - Oudie

Two reasons
1 we rarely get clearances to enter
2 The constant chatter on the R/T interupts cockpit conversations and is very distracting, possily a reason why some infringements happen.

bb

Then even more so the reason not to raise the floor! :)

If one can't get a clearance, it would mean it is unsafe for more aircraft to operate inside it. (ie. too much traffic)

By raising the floor, there's a risk of further compacting aircraft inside it into tighter spaces, as well as allowing even more aircraft to fly beneath it without adequate separation. Now factor in the amount of airspace busts and you get an unsafe environment on both sides of the fence.

IIf only that was the reason. I have sat next to a controller with zero traffic within 40nm and asked how one would ask for a clearance to cross his class "D" airspace. His answer? I dont let anyone in to my airspace, neither with nor without an engine or transponder. The sky was empty.....That is the problem.
bb

bad bear,

Name and shame (or at least provide an unambiguous clue!) ;)

Really? If what you say is really true, I can't see why does he still has this job.

I see absolutely no reason for this TMZ whatsoever. The vast majority of traffic in that area is VFR outside CAS, so the lack of radar cover is irrelevant. Aircraft being vectored into GLA won't be affected by this anyway, so all I see it as is another airspace grab by Glasgow.

Totally pointless and just another bit of unnecessary complication for flying VFR in this area.

soaringhigh650 wrote; Quote: we rarely get clearances to enter

Then even more so the reason not to raise the floor!

If one can't get a clearance, it would mean it is unsafe for more aircraft to operate inside it. (ie. too much traffic)

By raising the floor, there's a risk of further compacting aircraft inside it into tighter spaces, as well as allowing even more aircraft to fly beneath it without adequate separation. Now factor in the amount of airspace busts and you get an unsafe environment on both sides of the fence.

---------------------
For a literally graphic illustration of the number of movements outside UK controlled airspace, see pages 23 and 24 of this report:

http://www.aaib.gov.uk/cms_resources...d%20G-CKHT.pdf

There are, of course, some very busy areas of controlled airspace, for example around Heathrow, Luton, and Stansted. There are also areas which have nothing like as many movements as that, and are far less busy than the surrounding class G which everything else is forced to use.

Chris N

Thanks for that. Yeah, the image shows the tracks flown by some 118 aircraft. It doesn't show everything else that was happening at the time (e.g. departures/arrivals to Brize Norton and Lyneham).

Interesting! Do you have these stats?

The whole purpose of controlled airspace is to improve aviation safety by reducing the risk of midair collisions in areas of higher density air traffic operations. It is not there to squeeze this traffic into tighter corridors.

Soaring, you need to find the previous consultation on the Glasgow CAS. The response put together by the LAA showed it to be one of the largest and emptiest pieces of controlled airspace in the UK.

But with the usual approach that seems to come from public or quango employees doing what they are paid for is the last thing they would ever want to do.

This TMZ is simply not needed, the TMA is already far too big for the amount of traffic using it.

I see. So controlled airspace has been put in the wrong places? Difficult to believe then why the airspace designers still have a job.

soaringhigh650, what makes you think UK airspace is designed? Basically it evolved and much of the airspace is simply historic. We don't have DC3s on public transport over here any more but the airspace would be suited to them. Modern twin jets climb at 750-1000' per nm and Constant Descent Approaches are what one would hope to see, i.e. 3 degrees or 330'/nm. Fortunately last August the CAA having acknowledged that there are large areas of unused airspace acted promptly and came up with a method of getting rid of old and unused airspace without long and expensive Airspace Change Proposals. I hear NATS accepted this view also and have been looking to work with GA groups to release airspace. Any one can sponsor a change now without incurring great costs, perhaps someone will help out by sponsoring an ACP to raise the base here by 2,000' and solve the problem?
bb

A few things we need to get straight here.

(1) this is nothing to do with Glasgow, whether in terms of their airspace or their air traffic radar services. The TMZ is for the Lowther Hill radar, used by Scottish

(2) this is not an extension of controlled airspace. You won't need a clearance to enter it and you won't need to be talking to anyone. It will remain Class G airspace where you are free to fly anywhere you want, even IFR, without speaking to anyone.

(3) this is a temporary TMZ, not a permanent airspace change. It will be removed once they've got a permanent solution for the Clyde wind farm (just as they did for the Whitelee wind farm last (?) year).

But I agree it's pointless, and here's why:

if you're in a non-transponding aircraft flying at 3499ft, not talking to anyone, you can fly through the area quite legally. Controllers at Scottish will see your radar return and assume that you are flying below 3500ft - because they have no information on your height. When you're beyond the TMZ boundary you can climb to 5499ft and fly there quite legally. The controller will continue to make the same judgement. He won't vector any aircraft around you because he deems you to be below CAS.

Now, if you fly through the TMZ at 5000ft without a transponder and not speaking to anyone, the controller will still assume (this time wrongly) that you are below 3500ft in the TMZ area. But you are no threat to his traffic because it is all inside CAS at 6000 and above. So the controller's actions will be the same. Primary-only and not speaking to me = not inside, nor seeking to enter CAS, therefore not a factor.

The key question, to my mind, is what recent evidence there is of vertical infringers of this part of the Scottish TMA, and how many of these are non-transponding. I'm prepared to bet it's very very few. But if I'm wrong and it's a significant number, then the even bigger question is, why doesn't Scottish make ALL of the airspace 2000ft below the base of the TMA a PERMANENT TMZ? Because at the moment, Scottish controllers have no way of telling whether a primary-only return within the lateral boundaries of the TMA is infringing vertically or not - unless it's reported as an airprox by another aircraft.

NS

soaringhigh650 wrote: “The whole purpose of controlled airspace is to improve aviation safety by reducing the risk of midair collisions in areas of higher density air traffic operations. It is not there to squeeze this traffic into tighter corridors.”

Not exactly, SH.

At the first CACAAC meeting I ever went to, in about 1975 (CACAAC was the predecessor of the UK NATMAC), a CAA chap made a statement engraved in my memory: "The prime remit of the Civil Aviation Authority is the protection of the fare-paying passenger."

That has been the biggest single influence, almost the only one, on the granting of new controlled airspace in the UK in all the time I have been involved with it. The secondary effects of crushing non-fare-paying-passenger traffic into chokepoints has rarely, if ever, been a consideration for the authorities.

Before my time, a British Gliding Association delegate was faced with a similar declaration. The authorities at that time said that safety outside controlled airspace was not their responsibility. He asked the question: "Then whose is it?"

Apparently this resulted in a prolongued pause, and no satisfactory answer , then or ever since.

In a more recent year, in a meeting at Duxford when proposals for transponder mandatory zones for Stansted were being discussed, I pointed out that the official documents proposing this were mistaken in saying there would be no adverse safety effects. I said it was inevitable that some non-transponder aircraft would be forced out of class G airspace where they spread out at the moment, and would end up in the chokepoint going round the corner of the new TMZs. But again, the authorities had no answer to this.

I have no statistics for movements through little used CTA/CTR/TMA areas - it is in their nature that these are not available in the public domain, as far as I know. If anybody else is able to point to them, I should be grateful for references, for future purposes.

Chris N

NorthSouth

I agree. The only action needed is for the TMZ in the Scottish TMA to be lowered to 5500' in the affected area, then any traffic which transits the TMA through the area is visbile. The CAA could also give NATS a temporary dispensation to provide an SSR only service to aircraft in the TMA which penetrate the wind farm area, to get round the Eurocontrol and ICAO rules which require primary radar cover in the TMA. Infringers are a red herring since we will not take action to avoid unknown traffic unless information is recieved that an aircraft is lost or in an emergency. With a primary target, you are probably not going to know which target it is anyway, at least not positively.

gasax

It is not CAS requesting anything. It is the wind farm peoples attempt to mitigate their planning obligations with a stop gap solution. Why not demand that the wind farm company put the primary radar required in place BEFORE the farm can go operational ? It might focus them on getting it put up in double quick time and wouldn't require any change which impacts operators.

Most empty piece of CAS ? It runs at about 75% capacity for most of the day with 3 or 4 peak periods where the demand is 100% or greater. The LAA response was for a different piece of airspace and a different control authority. This airspace has inbound and outbound traffic to/from Glasgow, Edinburgh, and Prestwick operating within it, as well as TMA overflights.

If the ability to meet the legal radar requirement is impaired, as it will in this development, something else has to be done. This practically can only either be additional radar coverage or a TMZ. I would prefer the former every time.

Captain Smithy

Controllers will use the term 'return' (primary) or 'response' (SSR).

Bad Bear

I see no need for it to be so low either. 5000', if you want a buffer, would suffice.

NorthSouth

We don't have TMZs extending 2000' below all NATS CAS bases at the moment. This policy would need CAA approval and I can't find it.

Bad bear

The base is to allow traffic to descend in to Glasgow (RW05) and Prestwick (RW31) on Continous Descent Approaches. It also allows SID departures to be in CAS at the end of the SID in the event of RT Failure. Raising the base is a non runner from the ATC point of view.

Bad bear

[QUOTE]It happened in the 1970s. The TMA was a Mandatory Transponder equippage area above 6000' way back then, as specified in the Air Navigation Order. When the Class C airspace came in at FL195 and above a few years ago, this was split up in to common constituent parts, applicable throughout the UK. There was no change to the requirement, except in name, so no ACP needed. Equippage is now covered by UK AIP GEN 1.5 Para 5.3 as mentioned. Between 6000' and FL100, equippage is covered by sub para 5.3.1 part (f)

Between FL100 and FL195, it is covered by part (e)

and above FL195 is covered by part (a).

.

Bad Bear

The controller is a fool. The CAA invite pilots refused a clearance to report it so that such controllers can be educated.

SAS

As mentioned, nothing to do with Glasgow, and no CAS being established. No clearance required and no contact with ATC needed, only prior approval if operating without a transponder ... if it comes in of course.

gasax

With respect, the LAA report was not about the TMA, it was about airspace proposed for Glasgow only. The TMA regularly creaks at the seams and regularly requires Air Traffic Flow Management measures .... do you really think that is because it is too big and empty ? The need for a TMZ is a different issue from that of CAS design and operation. Let's not fall in to the trap of linking the 2, as the proposal does to some extent.

Bad Bear

I'm sure you'd get a few objections from NATS and the airline operators. Boot on the other foot ;)

NorthSouth

Well actually he won't ... because he won't see you :E

10W......good post, have you ever thought of becoming an ATCO? ;)

10W wrote: "No clearance required and no contact with ATC needed, only prior approval if operating without a transponder ... "

Am I just being pedantic, to wonder why it is called a TMZ (Transponder Mandatory Zone) , when it can be entered without having a transponder?

The TMZs near Stansted justified the expression rather more, as I understand it, because the only exceptions are for people from local aerodromes with specifically defined procedures.

Or are the exceptions seen by the authorities to be similar in all these cases?

Chris N