Glasgow Transponder Mandatory Zone

[xrayalpha]

Hi all,

Youll maybe have seen the TMZ for Glsgow coming in next month.

Map is at http://www.caa.co.uk/docs/14/2009%2049%20Whitelee%20TMZ.pdf

The CAA says:
The TMZ will extend from surface level to 6,000ft. Most of the TMZ will be in established Class D airspace with two small areas in uncontrolled airspace.
Phil Roberts, Assistant Director of Airspace Policy at the CAA, said: “As the majority of the TMZ covers controlled airspace most aircraft that will be affected are already transponder equipped. The local flying club at Strathaven has been consulted and due to the temporary nature of the restriction are content that there will be no major impact on their operations.”

Now this raises several questions:

As the owner of Strathaven, I ws consulted, but the club members weren't - and they are up in arms!

Question 1: If almost all the TMZ is in Glasgow's zone - I calculate grand total of 10 sq miles is outside - then why is the TMZ necessary. Since any traffic in radio contact with Glasgow ATC is exempt from the transponder requirements, the TMZ doesn't actually apply inside the zone. It actually only covers 10 square miles!

Question 2. What is so important about those 10 square miles to flight safety that they are in uncontrolled Class G airspace, and have been for the past 12 months when a) the radar unit has been down for maintenance and b) the windfarm has been operating.

Question 3. If the problem has only arisen because the radar unit is back on line - after more than a year offline - and traffic has been operating safely during that period, why not just keep it switched off until December and not bother with this TMZ?

Question 4. Is it a co-incidence that the new boss of Scottish is the old boss of Glasgow, who has just caused a kerfuffle in Scotland with the Class E to Class D airspace change proposal.

Question 5. The maximum distance from the edge of Glasgow's CTR to the edge of the TMZ is just 4 miles. Wouldn't it be easier for Scottish control to re-route any traffic to avoid that four miles? Instead, we are introducing a temporary TMZ which is not on charts, not on GPS units and might get missed when scanning NOTAMs.

Question 6. When has such a TMZ ever been used in UK airspace before?

Question 7. So why test it out here?

Of course, some may think this proposal may actually help small airfields such as mine resist the growth of windfarms. (Strathaven Airfield is actually inside South Lanarkshire Council's preferred area for windfarm development - even though "airfield" is actually on their map!)

That was my view, so as owner of Strathaven, I had no objection to a temporary zone.

Others, the club members, see it as the thin end of the wedge.

Since it is dark at 3:30pm in december - and the weather is miserable! - then there will be less traffic near the corner of the Glasgow zone. So less chance of infringements. So the TMZ has reduced infringements. So lets make a TMZ permanent and put it all round the zone.

Then - just like the poll tax which was introduced in Scotland first - we'll get TMZs round all the English airports!

Comments please.

Still seems a lot of effort for 10 sq miles of airspace!

[Take up the Hold]

Why is it temporary. The area covers the windfarm to the east of the M77. Are they going to knock down the windfarm to let you operate without transponders. I think not.
TUTH

[xrayalpha]

TUTH wrote:

Are they going to knock down the windfarm to let you operate without transponders.
--------------------

The windfarm has been there for more than a year, so no need to knock it down! We've been operating without transponders all that time.

And if you talk to Glasgow on radio, you don't need a transponder.

In fact, the only time you need a transponder is if you are on more than a mile final for 09 Strathaven, since you - presumably - wouldn't still be on Glasgow's frequency then!

And since it would take you just seconds (ie less than a minute) to cover the distance (less than a mile?) from the edge of Glasgow's CTR until you are clear of the TMZ, that hardly seems a significant gap worth all this TMZ hassle!

Of course, you could still stay with Glasgow until you left the TMZ and then try and change frwquency to Strathaven as you try to land! That'll be fun.

[west lakes]

Contained within the Dundee thread

http://www.pprune.org/5141235-post499.html

[gasax]

It seems almost like an 'organised' scheme.

Humberside gets Class D - and has less than 50 CAT flights a day.

Norwich applies for Class D and has less than 10 CAT a day.

Stansted gets a TMZ - the first in the UK on the basis that they don't want to offer any service to GA - just keep them out.

And then Glasgow sufddenly need a TMZ to cover a small area which has had no radar for a year.

It may not be a 'plan', but there is certainly an underlying theme.

I'm with your members - if the TMZ is not promptly withdrawn then I believe we have something that needs to be fiercely resisted.

[flybymike]

You missed out Doncaster from the list of unnecessary class D. I reckon this is all part of a plot to form a mass of impenetrable controlled airspace to the East of the A1 for the full length of the country...:rolleyes:

[gasax]

You're right I was thinking about Doncaster but did not write it!

There does seem to be this horrible trend - and once established the inevitable RCOCAS statement.

[fisbangwollop]

I thought the CAA had to carry out a consultation process prior to this happening........I guess it may have slipped my notice but did anyone take part in that process???:rolleyes:

[Oldpilot55]

Gasax

Humberside has about 16 flights a day..4 to and from Aberdeen, 4 to and from Amshterdam. Plus a few tourist flights. A few helicopters to the rigs on a daily basis. Its not the busiest airport in UK. They do operate a very useful LARS, but they get paid handsomely for that.

[xrayalpha]

"I thought the CAA had to carry out a consultation process prior to this happening...."

Actually, I think it was all in a bit of a rush....

because we have to beat the English into getting the first UK TMZ!

Of course, I am now preparing a case for an exemption on compassionate grounds!

[zkdli]

GASAX - i wasn't going to say anything but I can't let you say that the TMZ at Stansted is so because "they" don't want to give a service just keep GA out - this is just not true.

There are procedures in place to allow operations in and out of Northweald, Hunsdon, Weathersfield etc. If you have a transponder then there is no requirement at all to talk to anyone while you are in the TMZ - as long as the transponder is on:)
If you don't have a transponder then you can still enter - just talk to Farnborough and they will arrange a transit.
If you are nonradio it becomes difficult but again not impossible.
the only reason the TMZ is at Stansted is to give controllers and aircrew a fighting chance when flying in the CTA above the TMZ - these CTAs suffer a very large number of incursions, if the aircraft is squawking then at least the safety nets for ATC, and TCAS, have a chance to prevent a very close encounter. With no Squawk every one is reliant on seeing the other aircraft and avoiding it - and we all know how effective see and avoid is....

[Radarspod]

Lets add a few facts in here plus my view on what this is about:

The TMZ is needed to ensure detection of aircraft through an area of airspace in which Primary Radar is pretty much next to useless due to clutter produced by a significantly large wind farm. By requiring the use of transponders in that area, ATC have some way of controlling and separating traffic. It's not just Glasgow ATC that are monitoring of controlling movement here, there is also ScACC area control and Military radar operators.

The Lowther radar head is coming back into service soon, following an upgrade. The wind turbines will affect it as much as the old one, and it caused problems before. It was asked why the TMZ is necessary and why can't we wait till December? - its because as soon as Lowther radar head comes back in, out goes the Glasgow airport one. These are the two primary radars providing low level coverage of this area to civil area and ScATCC Mil controllers. So if Lowther is all that is available at that time, and the windfarm produces primary clutter over the windfarm, then secondary radar is the remaining method to track aircraft through the area, hence the temporary TMZ. Come December, on move to the new control centre at Prestwick, other primary radars can be brought in and the TMZ is no longer required (I assume that's why its December :}).

This isn't the "thin end of the wedge" - it's a perfectly straightforward TEMPORARY implementation of the TMZ concept. :ok:

RS

[gasax]

The TMZ concept is actually the problem!

The talk about the Stansted TMZ - yes you can get entry into it without a transponder - do you get that permission from Stansted? Oh no they are far too busy to bother with the own adjacent airspace, they'll leave it to Farnborough to try and co-ordinate it. The chances of a timely transit? Just about zero given the radio traffic and the need to co-ordinate with Stansted.

Glasgow have a huge Class D area. Mostly it is empty as the 'consultation' on upgrading the Class E section of the TMA to D clearly showed. For a year they have no primary coverage of an empty bit of sky (from their viewpoint, but not of course from Strathaven!), suddenly it is 'me too, me too', we need a TMZ to keep control of a bit of sky that generally not a lot happen in - from the Glasgow perspective.

Oh yes it might be a little inconvenient for Strathaven - but who cares? Not Glasgow. Of course Glasgow already know what traffic is there because everyone has to talk to them to get in.........

[NorthSouth]

gasax:
I think you need to read radarspod's post. The temporary TMZ's not for Glasgow it's for Scottish.

Having said that, I can't see why Scottish need a TMZ extending below the base of the TMA, because they have always had (and continue to have) a policy of deeming any primary-only returns within the boundaries of the TMA to be operating below the TMA. If they decide to abandon that policy all movements in the TMA would stop forthwith because controllers would have to treat every microlight chugging around central Scotland at 500ft (and every wind turbine) as if it was an intruder inside the TMA.

On the subject of Glasgow's controlled airspace, perhaps you've forgotten that they agreed earlier this year, in response to GA concerns, to release a great big chunk of their CTR to Class G? As it happens it's also the bit where the TMZ is (although of course the TMZ will have gone by the time the airspace goes to Class G).

XA:As the owner of Strathaven, I ws consulted, but the club members weren't - and they are up in armsIf that's the case then I think you must carry the responsibility for any incompleteness of the consultation process. It seems to me to be entirely reasonable for the CAA/BAA/NATS to assume that, as owner of the airfield, you would consult your own tenants/members. And if the CAA quote of your position is accurate, you surely haven't a leg to stand on in criticising them because you apparently told them you were "content that there will be no major impact on [your] operations".
NS

[gasax]

I think you need to read radarspod's post. The temporary TMZ's not for Glasgow it's for Scottish

It's not just Glasgow ATC that are monitoring of controlling movement here, there is also ScACC area control and Military radar operators.


I took that to mean it is Glasgow controlling this area (especially as about 80% of it in within the Glasgow Class D area!). Either way if it had been accepted for a year what is the hurry? where is the consultation?

I would take your point though that I would not like to be in XA's position if the CAA statement is true!

[Dr John Watson]

Northsouth

interesting to hear that Glasgow are giving up some of their CTR. Has there been anything pulished eg a map to show what is to be re designated as Class G and do you know when does this come about?

[fisbangwollop]

WHITELEE WINDFARM TEMPORARY TRANSPONDER MANDATORY ZONE (TMZ)
The purpose of this letter is to advise you of the establishment of a temporary Transponder Mandatory Zone (TMZ) from 15 September until 6 December 2009 over the Whitelee Windfarm, south of Glasgow, to mitigate its effect on the NATS Lowther Hill radar. The TMZ will be established under an SI approved by the DfT.
Windfarms generate unwanted returns on primary radar and can degrade the performance of Secondary Surveillance Radar. In April 2006 the UK’s largest onshore windfarm was granted planning permission to be built at Whitelee, south of Glasgow. A key element to gaining consent was the combined effort of the British Airports Authority, National Air Traffic Services, Civil Aviation Authority and Scottish Power to ensure the project would have no adverse effect on the safety of air traffic in the area. The agreed solution was to provide a new radar at Kincardine in Fife, this radar is already in use by Glasgow Airport. NATS will be unable to incorporate the radar feed until the new Prestwick Centre comes on-line in Dec 2009. The temporary TMZ has therefore been put in place to mitigate the effect of the wind turbines on the Lowther Hill PSR and allow an ATC service to be provided using SSR only with no adverse effect on the safety of air traffic in the area.
The TMZ will extend from surface level to 6,000 feet. Most of the TMZ will be in established Class D airspace with two small areas in uncontrolled airspace. Aircraft without a transponder will be able to enter the TMZ if under the control of Glasgow International Airport.The TMZ will be withdrawn once NATS’ new air traffic control centre at Prestwick comes online in December 2009 with a feed from the new radar station at Kincardine in Fife. This will provide improved coverage of the airspace around the area. The implementation of the temporary TMZ will have no influence on the upcoming Glasgow ACP. The TMZ is seen as a short-term mitigation to maintain safety whilst supporting Government long-term renewable energy policy.
Civil

[NorthSouth]

gasax:I took that to mean it is Glasgow controlling this area (especially as about 80% of it in within the Glasgow Class D area!). Either way if it had been accepted for a year what is the hurry? where is the consultation?Glasgow is obviously the authority for the Glasgow CTR, but Glasgow IFR departures will typically be handed off to Scottish when they're established on the SID and still well inside the Glasgow Zone. Consequently Scottish needs to be able to see those aircraft clearly on radar as they pass over the wind farm. There's a short period when the Lowther Hill radar (Scottish's main radar for this airspace) comes back online but before the New Scottish Centre comes online enabling the new Kincardine radar to monitor that airspace. The TMZ's only to cover that short gap.
I think FBW's answered your "where is the consultation?" question, although I must say it didn't reach the parts that some other consultations have done. And as I said before, I can't see the reasoning for the bit of the TMZ below the TMA - and it's the only possible contentious bit.

Dr JW: the Glasgow ACP can be found here (http://www.nats.co.uk/text/251/glasgowconsultation.html). NB the proposal to release the SE corner of the CTR to Class G is in the feedback report, not the "final" proposal. I don't know what's happened since the feedback report but there's certainly no change in the next AIRAC cycle so it'll be at least 22 October.

NS

[fisbangwollop]

From what I can see this would never affect the SID's as well above 6000ft by the time they get any where near the TMZ, I guess only IFR arrivals for R/W 05 would be affected as they are vectored from the lanak holding fix??:cool:

[PPRuNe Radar]

CAA Policy for TMZs demands that consultation takes place under the procedures laid down in the Airspace Charter. So where was this 'consultation' made available to the public, allowing airspace users to make their thoughts known ?

This particular TMZ might have perfect logic for enhancing safety, but what's the point of having a laid down process if the CAA and other agencies can just dispense with it if it suits them ?

[fisbangwollop]

PPR....That was the point I made in post no.8!! :cool::cool:

[NorthSouth]

fbw:From what I can see this would never affect the SID's as well above 6000ft by the time they get any where near the TMZ, I guess only IFR arrivals for R/W 05 would be affected as they are vectored from the lanak holding fix??It's not that far past Fenwick so any traffic only just meeting the climb gradient could be only just reaching 6000 in that area. Plus I guess they want a buffer below that to ensure clearance from any conflicts. I don't believe Scottish hands over LANAK arrivals to Glasgow as late as the TMZ area (isn't LANAK the handover point?).
NS

[fisbangwollop]

Yea the traffic is normally chucked to glasgow heading towards Lanak in the drop to min stack level of F080...Glasgow then vector the traffic round on to ils for 23 or 05, very rarely does traffic go to the hold due perfect sequencing by Scottish...:cool::cool:

[Dr John Watson]

fisbangwallop,

aye right -

on the handover my roof is used as a marker on most days or that's how it seems. Can't they be routed over Douglas or Larkhall. Don't know how many times I have strained my neck looking up to see who is coming in.!!

Most I have seen in the hold at anyone time has been seven.- all taking about 8 minutes to come round again & again & - well you get the picture.

This year has not been as busy as previous years so have enjoyed the G&T's in the garden more.

Keep up the good work

[off watch]

"towards Lanak in the drop to min stack level of F080" - a minor point but Min Stack depends on the Glasgow QNH so is usually FL70,80 or less often 90.

"Can't they be routed over .... Larkhall?" - WHAT ! - & disturb the flute band practice ? ;)

[fisbangwollop]

Yea obvious PF QNH dependant but on average on the year FL080 will be min stack.....unless on pretty ****ty days with very low pressure we may have the odd 90...:cool::cool:

[fisbangwollop]

Minimum Stack Level
The lowest flight level available for use in the TMA is always based on the GLASGOW QNH according to the following table

It is perfectly acceptable to place inbounds on a radar heading which takes the aircraft towards base leg for the runway in use provided that no traffic is already holding for that airport and no more than two aircraft are so positioned simultaneously.

Glasgow QNH Min Stack
1014 or more FL70
978 to 1013 FL80
977 or less FL90


:cool::cool::cool::cool:

[xrayalpha]

For the record, consultation was a telephone call less than a fortnight ago, talking about "an area over the windfarms".

Co-ordinates were only received by email on August 17th.

This is now just nine days later - so hardly surprising that I was only able to speak as owner and operator of the airfield and not, as the CAA claim, on behalf of the club and flyers based there.

You try letting club members know, explaining what is going on and then getting feedback in just a few hours!

*****

I repeat, this will only affect traffic in a 10 sq mile area. All the rest of the proposed TMZ is in Glasgow's Class D, where all traffic will be in radio contact so exempt from the transponder requirements.

In fact, most will be in radio contact before the enter the TMZ, since it is not accepted practise to enter the zone without making radio contact!

I can see why the CAA couldn't be bothered going through the full TMZ rigmarole for just 10 sq miles. So why bother introducing it?

Remember, it is ten square miles, not 10 miles by 10 miles (100 sq miles!)

So this is a TINY bit of airspace.

Hence many people's supicions that there is an ulterior motive.

It really is hard to see the flight safety case, honestly. Especially as it is accepted safe practise to class unknown returns as being in the Class G below the existing Class D. Or will that change and transponders become mandatory everywhere?

[NorthSouth]

XA: if the CAA's quote of you is no more than someone's precis of a memory of a phone conversation then that surely doesn't meet the terms of CAP 724/725. But if it's something you gave them in writing then it's rather more problematic. It seems you told them - perhaps on the basis of scant information - that you had no problem with the TMZ proposal, and you didn't anticipate that your members would take a different view. But if the consultation was primarily by phone that suggests that the CAA/NATS decided that since it was such a small area for such a short period it wasn't worth consulting more extensively. That is rather worrying because this and the Stansted TMZ consultations appear to be challenging the long-standing practice that unknown primary returns under CTAs and airways are deemed to be vertically separated from traffic inside CAS, but doing so without expressly challenging the policy.
NS

[VectorLine]

the long-standing practice that unknown primary returns under CTAs and airways are deemed to be vertically separated from traffic inside CAS,

Windfarms cause clutter on primary radar.
To get rid of the clutter, the primary radar will be blanked over the windfarm.
So, there is nothing to deem OCAS.
However, there needs to be some assurance against possible airspace infringers
Hence a TMZ.
The TMZ is temporary because when the new centre comes on line, the radar at the Kincardine Bridge will fill in the gap that is currently blanked.

If you read the letter that was posted by FBW properly you will see that this was not a consultation. It's not an airspace change so it's not covered by CAP724/725.
The CAA put this measure in under their exisiting powers to preserve airspace safety. They've always ben able to do this - even before the TMZ policy.

[xrayalpha]

OK,

There is a major air safety issue here.

So - taking into account that only people who have radios and are in communication with Glasgow are allowed in the CTR, and are thus emempt from the TMZ - the actual area is less than 10 square miles.

A 2nm radius zone around, say, and airport like Cumbernauld, covers pi r squared of ground - ie 2 x 3.14 x 3.14, which equals 19.72 square miles.

So why the "iron fist" of a TMZ over an area half the size of an ATZ round a local airport.

Indeed, if Strathaven had an ATZ, a couple of those 10 sq miles would be inside it!

Why not just route traffic around that tiny bit of airspace, rather than all this hassle.

ps. Good idea from a controller who just heard about this yesterday! Why not have a clear plastic sticker to put on half mill and quarter mill charts outlining this. Then hand them out at Scottish airfields and flying schools.

No point in having a TMZ and then people busting it - mind you, how would anyone know since they can't see the primary returns!! Or if they can see them, ATC think they are windfarms. Where's the flight safety? (oh, yes, I forgot, we are talking about Class G, see and avoid, oops! I was thinking that this was a really important piece of airspace!!)

[NorthSouth]

VectorLine:Windfarms cause clutter on primary radar.
To get rid of the clutter, the primary radar will be blanked over the windfarm. So, there is nothing to deem OCAS. However, there needs to be some assurance against possible airspace infringers Hence a TMZLet me restate. Assurance against possible bottom-up infringers of controlled airspace is currently not provided by establishment of a TMZ anywhere in the UK. It is provided by Rule 35 of the Rules of the Air Regulations which state that you cannot enter controlled airspace without a clearance. Consequently ATC practice has always been that any primary-only radar return which does not correspond with an aircraft which has been given an ATC clearance to enter that controlled airspace is deemed to be below the base of that airspace. If the reason for the temporary TMZ we are talking about here is that the primary radar is being blanked, therefore controllers would have no information on any non-squawking traffic in that area, there are two questions:
1) given that all primary-only returns in that area are currently ignored by Scottish controllers (i.e. deemed to be below CAS) when the radar isn't blanked, what's the advantage of blanking?
2) there are now quite a lot of wind turbines around, including some in large numbers not too far from this area. Why don't those have TMZs over them?
NS

[Floppy Link]

XA

you've done (r x pi squared) for the area. Answer should be 2 x 2 x 3.14 = (12.56)