ATZ Size

[Pierre Argh]

Recently discussion on the ATC Matters Forum started when a non-UK based aviator was "shocked" to learnt that some UK airports operate in Class G without the protection of CAS around them.

Without wanting to repeat the debate here, another contributor has suggested larger ATZs at some airports might be a solution where they have no more protection than the local flying club. I'd suggest this is a good idea, perhaps something of similar dimensions to the MATZ (5nms radius, SFC - 3000', with a stub out to 10nms aligned with main instrument RWY)... but beyond that there should be no change in airspace status (i.e. I am not advocating more CAS)

Aware that the GA world often has strong feelings on the further establishment of airspace, do contributors to this Forum feel that more protection is necessary at certain airports and what would you suggest?

[WorkingHard]

Pierre what you suggest has some merit but with the mental state of airport management in this country they would simply see it as a quick first step to CAS around their precious "International" airports. Until something is achieved to update and integrate training for all concerned with aviation and something done to rid us all of the "us and them" attitudes then nothing except full CAS will satisfy the airport operators. Incidentally what status do you expect to confer on the "MATZ" as well as the ATZ?

[dublinpilot]

I think Piere is suggesting an increased ATZ size rather than a new form of airspace.

The trouble with this is that an ATZ might as well be class D as I understand it. One there is full ATC there, then you require their permission to enter, and you must follow their instruction once inside. Not much different to class D.

where they have no more protection than the local flying club.

You never mentioned who "they" are, which in itself makes it obvious that you see this from the airlines point of view.

An alternative point of view is that the airlines should operate from the regional airports with the protection of controlled airspace. If they choose to operate from smaller airports without the protection of controlled airspace, then that is their choice. They do it to save money and increase profits, and they shouldn't expect the rest of us to pay the price for that, by suffering further regulation and delays.

What if each airline decides to operate from a different airport, to get a better deal than their rival. Do we end up covering the whole country in controlled airspace for the same fleet?

dp

[chevvron]

Ah but Exeter and Humberside ARE regional airports, and they don't have regulated airspace. In any case, if the ATZ remains class G, then class G VFR rules will apply (140kt or less anyway) rather than class D rules; creates known traffic without as much restriction for transits.

[rodan]

Originally Posted by chevvron

Ah but Exeter and Humberside ARE regional airports, and they don't have regulated airspace. In any case, if the ATZ remains class G, then class G VFR rules will apply (140kt or less anyway) rather than class D rules; creates known traffic without as much restriction for transits.

I believe that a class G ATZ of increased dimensions would be more restrictive than class D, not less. RAS separation standards (3nm/1000' between identified traffic) would apply between the majority of IFR passenger transport a/c and VFR transiters, whereas with a class D zone the separation can be reduced (isn't even required at all, strictly speaking). In both cases clearance to enter would be required. I imagine this'll be where someone suggests class E, but where the issue is conflict between unknown VFR against IFR traffic on an instrument approach, class E completely fails to resolve this.

[chevvron]

Rodan: ATC wouldn't necessarily provide RAS all the time; at my airfield the density of known transit traffic means that on occasion we only provide RIS when circumstances permit eg instrument approach in VMC. Commercial air transport pilots seem to be happy with this, especially with the advent of TCAS, even if the transit is non-squawking.
One advantage of a class G ATZ over a class E CTR is that a clearance and 2-way comms are not required in class E airspace, whereas they are both required in an ATZ notified as ATC.

[bookworm]

Originally Posted by chevvron

In any case, if the ATZ remains class G, then class G VFR rules will apply (140kt or less anyway) rather than class D rules; creates known traffic without as much restriction for transits.

VFR minima in class D are set so that there is a reasonable chance of resolving a conflict between an IFR and a VFR flight visually. For flights in a vis of less than 5 km, SVFR is required and ATC provides separation.

If you're going to permit VFR flights to operate in visibilities down to 1500 m without separating them from IFR flights, you might as well not bother with the regulated airspace at all! The chances of resolving a conflict visually at a closing speed of 250 kt in a vis of 1500 m is virtually nil.

[matspart3]

I don't completely agree with the assumption: -

'...but where the issue is conflict between unknown VFR against IFR traffic on an instrument approach, class E completely fails to resolve this'

I'm not suggesting that its not correct, it is, but with a Class E zone shown on a map, I would imagine the vast majority of users would call the ATC Unit in question anyway. You'll still get the odd glider/military/non-radio/luddite but the enlightened amongst us will realise that you can get a sensible and relevant Air Traffic Service, free of charge when transitting a zone!

The problems of the perception of CAS are more fundamental, IMHO. There is a certain element amongst the GA community that really believes that any CAS is a no-go area unless you're in a 737. They don't understand the subtleties of airspace classification or how to 'use' the service. Furthermore, abyssmal RT standards mean they're either overawed by the prospect of attempting a transit or simply too cr@p on the radio to be trusted to transit! Then you get the arguments that 'I shouldn't have to use the radio to fly in my xxx type from Upper Lower Little Snodbury to Wotsit under the Over'. True, as a PFA flyer, I enjoy the true freedom of Class G too, but it's reassuring to know that there's a wealth of info and assistance available to me if I choose to use it. Nobody bats an eyelid about drivers having to learn the Highway Code before being let loose on the road, why do (some) see the RT test as such an imposition?

The problem isn't just with pilots. There are certain ATC Units, who operate their Class D Airspace almost like Class A. I've had some very odd zone clearances before (hold here, orbit there), which I can envisage in plan form on the radar screen. The simple fact that I can see your ILS traffic and will easily avoid him if he goes around is overlooked and I'm afforded a 'Separation' that I don't actually need by default. TCAS and Mode S don't help these scenarios either. This problem will get worse, particularly as NATS feed their new ATC recruits straight into Approach Radar, with minimal instruction or expereince of either GA, VFR or the dreaded mythical world of Outside CAS!

[Chilli Monster]

Originally Posted by matspart3

There is a certain element amongst the GA community that really believes that any CAS is a no-go area unless you're in a 737. They don't understand the subtleties of airspace classification or how to 'use' the service.

But to prove it is possible - see HERE

[mm_flynn]

Originally Posted by matspart3

The problem isn't just with pilots. There are certain ATC Units, who operate their Class D Airspace almost like Class A. I've had some very odd zone clearances before (hold here, orbit there), which I can envisage in plan form on the radar screen. The simple fact that I can see your ILS traffic and will easily avoid him if he goes around is overlooked and I'm afforded a 'Separation' that I don't actually need by default. TCAS and Mode S don't help these scenarios either. This problem will get worse, particularly as NATS feed their new ATC recruits straight into Approach Radar, with minimal instruction or expereince of either GA, VFR or the dreaded mythical world of Outside CAS!

I think this is a big element of the 'automatic GA reaction'. The system in the UK seems designed to encourage controllers to provide Class B like service in a number of Class D zones - Which for Manchester and a few others may actually be correct. However, most of the Class D areas are not very busy and providing the service as specified in the standard (i.e. just traffic info on VFR) would make the controllers life much easier, make the airspace much more accessible, be overall cheaper for society, and would mean that smaller airfields could justifiably have a Class D zone. Even after nearly two decades in the UK, I am amazed at the difficulty some small regional airports have slotting in transits. When I learned to fly at KHPN (some 200,000 mostly IFR movements a year!) there were very few occasions when a transit was not approved.

I also, have never gotten comfortable with the concept of me being on an ILS into a Class G airport with the knowledge that somebody else could perfectly legally be orbiting in IMC at the outer marker with out talking with anyone!

[London Mil]

mm flynn, I would agree. See my comments here:
http://www.pprune.org/forums/showpos...4&postcount=15