Flying into leeds CTA Class D aispace

[Gertrude the Wombat]

But if you are flying over London within gliding distance of the Thames, and are fully prepared to accept the consequences of ditching there, in my opinion the ultimate objective of the "land clear" requirement has been met.

Well, watching the Thames from the terrace of the House of Commons the other evening I saw an endless stream of boats all over the place.

Yes you would probably have a reasonable chance of missing most of them ... but with no engine you limited choice of where to go and I don't think that you could guarantee that you could always miss all the boats.

[mrmum]

being as different as you can ever manage within ICAO limits.

IIRC years ago pre-JAA perhaps, we had the world record for number of differences filed with ICAO.

[mrmum]

a CTA is simply a class D (rather than a class A) TMA.

Not sure that's totally correct, don't have a 1/2 mil. South with me at the moment, but the Daventry and Worthing CTA's seem to spring to mind as being class A. Perhaps somebody with a chart to hand could have a look and confirm (or refute).

[Jan Olieslagers]

More curious than ever: what then makes these class A CTA's differ from class A TMA's ? What is the real definition of a CTA and what separates it from a TMA? Why the need to declare CTA's separately? Are they really a UK-only thing?

[asyncio]

ICAO definitions are

ATZ An aerodrome traffic zone is an airspace of defined dimensions established around as aerodrome for the protection of aerodrome traffic

CTA A control area is a controlled airspace extending upwards from a specified limit above the earth

CTR A control zone is a controlled airspace extending upwards from the surface of the earth to a specified upper limit.

TMA A terminal control area is an area normally established at the confluence of ATS routes in the vicinity of one or more major aerodromes

So basically a TMA is a large shared CTA which connects to lots of airways. The airspace classification is independent of the airspace type.
Or at least, that's how I've always understood it.

[BackPacker]

CTR A control zone is a controlled airspace extending upwards from the surface of the earth to a specified upper limit.

Here in NL we have a few stubs (of the Schiphol CTR) that extend from 1200' upwards.

[flybymike]

Indeed. Just to further confuse the issue, a MATZ is a zone but also has stubs commencing 1000ft agl!

[asyncio]

Here in NL we have a few stubs (of the Schiphol CTR) that extend from 1200' upwards.

That would explain Jan's confusion then.
I found a chart of the Schiphol airspace here, and they are calling them all CTRs, and arranging the airspace like this

TMA TMA TMA TMA TMA
....CTR2CTR1CTR3....
........CTR1........

vs

TMA TMA TMA TMA TMA
....CTA CTA CTA....
........CTR........

or

TMA TMA TMA TMA TMA
....CTA CTR CTA....
........CTR........

which are both used in the UK. So I'm not sure which is the ICAO way of doing it.

[BackPacker]

I guess the difference is that those CTR stubs extend to the same altitude as the main CTR, and are controlled by the same ATC unit (Schiphol Tower), while a CTA would overlay the CTR to a different altitude.

Just guessing here, but by introducing a CTA between the CTR and the TMA they may have had to add an additional layer of ATC as well.

But as I said earlier, for us uncontrolled VFR flyers the difference between a CTR, CTA and TMA is really moot. Just look at the type of airspace involved, and look up the controlling authority if you want to go through. And if you can't go through, go around.

[asyncio]

Just guessing here, but by introducing a CTA between the CTR and the TMA they may have had to add an additional layer of ATC as well.

The CTA is usually controlled by the same people as the CTR, it seems to be purely how you label the block of airspace.

for us uncontrolled VFR flyers the difference between a CTR, CTA and TMA is really moot.

I think that's true for IFR as well, its only the airspace class that makes any real difference.*

*I think ATZ and RA are the only airspace types which have any real requirements. The rest, DA, HIRTA, MATZ etc. are just 'hints'???

[dublinpilot]

The main differences between a CTA and CTR are:

1. A CTR extends to the ground and a CTA starts above the ground.
2. SVFR is availbale in a CTR but not in a CTA.

A CTA is far from a British peculariaty, and is quite international. You'll certainly find them all across Europe.

dp

[bookworm]

Just guessing here, but by introducing a CTA between the CTR and the TMA they may have had to add an additional layer of ATC as well.

I think it's just a quirk in the NL (in fact, only at Schiphol) that the stubs are called "CTRs". Everyone else would call them CTAs, and have the same ATSU controlling them as the CTR.

We regularly fly over Amsterdam at 1000'-1400', with the full permission of ATC (as Amsterdam lies in the Schiphol CTR). There is no space whatsoever (not even a park) on dry land to "land clear" but there are several canals and lakes that you can use.

The difference is that ICAO Annex 2 and NL requirement is

Except when necessary for take-off or landing, or except by permission from the appropriate authority, aircraft shall not be flown over the congested areas of cities, towns or settlements or over an open-air assembly of persons, unless at such a height as will permit, in the event of an emergency arising, a landing to be made without undue hazard to persons or property on the surface. No aircraft shall be flown acrobatically except under conditions prescribed by the appropriate authority and as indicated by relevant information, advice and/or clearance from the appropriate air traffic services unit.

The UK requirement to be able to land clear of the congested area, which is more restrictive.

Anyway, we're not talking about overflying London here, as there are specific rules for overflying London in a SEP anyway.

There are no special rules for overflying London in an SEP aeroplane. There are some that relate to helicopters.

[Northern Highflyer]

To answer the original post, I have flown over Wakefield many times.

I just give them a call and tell them something along the lines of, I will be overhead Wakefield for approx 10-15 minutes, not above (for example) 2000ft, on Leeds QNH and will remain clear of controlled airspace.

When done I let them know this and that I am moving on, never had any problems, and they are very happy if you keep them informed what your plans are.