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Airspace Classification Help for PPL Exams

I’m currently revising Air Law and Ops. I don’t quite get some of the finer points of Class C, D and E airspace. I may be over-thinking this as I know enough to get through the exam but cannot get my head around how the differences work in practice.

In class D ATC separate IFR flights from one another and beyond this provide traffic info only. Separation between IFR and VFR flights and between VFR flights is up to the pilots themselves. However if an IFR flight is following a clearance, presumably heading/FL, then how can it avoid a conflicting VFR flight without altering heading/height? Does it request a change?

By issuing a VFR flight with a clearance, eg. cross CAS not above 3000’, is ATC not providing a separation between VFR and IFR flights? Is the VFR flight kept below 3000’ to keep it away, ie. separate, from IFR traffic? By refusing a zone transit to VFR traffic the same thing is happening, it is being kept separate, but in a more extreme manner.

Obviously ATC has a duty to help ensure the safe conduct of all flights within its area of responsibility but it seems to me that what happens in practice for class D (in the UK at least) more approximates how class C is meant to operate.

I could fill this post up with all sorts of further examples but hopefully you can see the concept that I am struggling with. Any help is much appreciated.

S57
EGBJ, United Kingdom

S57 wrote:

However if an IFR flight is following a clearance, presumably heading/FL, then how can it avoid a conflicting VFR flight without altering heading/height? Does it request a change?

You don’t need permission to perform a manoeuver that saves your life. Also the manoeuver would most likely still be within the prescribed corridor. In real life there would be a TCAS alert on the bigger iron which gives enough time to discuss the source of action with ATC. Also it’s very unlikely as VFR traffic still subject to a clearance which would include the permitted trajectory. What C/D really do is increase capacity by not requiring separation minima for VFR traffic.

S57 wrote:

By issuing a VFR flight with a clearance, eg. cross CAS not above 3000’, is ATC not providing a separation between VFR and IFR flights? Is the VFR flight kept below 3000’ to keep it away, ie. separate, from IFR traffic? By refusing a zone transit to VFR traffic the same thing is happening, it is being kept separate, but in a more extreme manner.

If by separation you mean “won’t crash” — yes. However, under ICAO “separation” means a lot more and those criteria are not guaranteed.

I think in practice it is not an issue. VFR is VFR regardless of airspace. In C/D airspace you will get clearances like “cleared to final as number two behind landing aircraft, report visual”. If you report negative visual, the tower may chose to extend you or make you slow down or something to increase separation.

ENVA ENOP ENMO, Norway

achimha wrote:

What C/D really do is increase capacity by not requiring separation minima for VFR traffic.

achimha wrote:

If by separation you mean “won’t crash” — yes. However, under ICAO “separation” means a lot more and those criteria are not guaranteed.

Thank you. This does help me make more sense of it.

S57
EGBJ, United Kingdom

Except in the real world, class D is not operated like that in the U.K.

EGCJ, United Kingdom

I don’t quite get some of the finer points of Class C, D and E airspace

Don’t worry, almost nobody else gets it either

There are two kinds of air molecules: CAS and OCAS. The former needs a clearance (which in France, just to baffle pilots expecting it, is readily given but rarely spoken) and the latter doesn’t.

Class E is CAS for IFR and OCAS for VFR.

VMC is when you are not in cloud. IMC is when you are in cloud.

VFR is when you are not supposed to be in cloud (but if you are, nobody knows).

Otherwise, just learn the horrible rules (a google / images on “airspace classification” digs out enough, mostly American though) and pass the exam and enjoy flying (and keep out of CAS unless cleared to enter it)

Traffic separation by ATC is a tricky topic, because the rules are different according to airspace class and whether one or both aircraft in question are VFR or IFR, and probably day/night. In reality many people lie about being VFR but are actually in IMC. It works OK because the sky is big and very little GA flies in CAS (or countries which have a lot of CAS have little GA).

Except in the real world, class D is not operated like that in the U.K.

Hmmm… not a lot of information there! Class D is CAS. That means you must have a clearance to go into Class D. Just because you can fly in France (and nowhere else) and get it with the useless and ambiguous phrase “radar contact” (which would enable a prosecution because you never got “cleared”) doesn’t mean it will work the same way elsewhere. A lot of UK Class D you will never get cleared into but potentially a lack of clearance could happen anywhere. I have been refused a clearance in every country I have ever been in, at some point.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

I have been refused a clearance in every country I have ever bin in, at some point

Think you might want to improve your R/T to improve your chances of getting a clearance, then…….

(ducks and runs for cover)

Last Edited by Steve6443 at 14 Jul 14:32
EDL*, Germany

Peter wrote:

Just because you can fly in France (and nowhere else) and get it with the useless and ambiguous phrase “radar contact” (which would enable a prosecution because you never got “cleared”) doesn’t mean it will work the same way elsewhere.

Definitely not only in France. In Hungary and Slovakia I have been “cleared into” class D airspaces by “radar contact”, “continue”, “direct destination”, “remain this frequency” (from FIC when they coordinated with APP) and other “clearly unambiguous” phrases. Not a single time I have heard “cleared” in such a situation in these two countries. OTOH, I have heard “cleared” in class F and G airspace from an (A)FISO or just some random dude with a radio who thought that he was the boss at a particular location so many times that I lost count. In these cases I tend to reply in a way that demonstrates that they were not clearing me for anything at the first place since no clearences are necessary or possible in those situations.

Last Edited by JnsV at 14 Jul 17:00
Hajdúszoboszló LHHO

Well, there are many countries in Europe where I have not flown VFR. However “radar contact” is nonstandard-ICAO phraseology. It’s fine for the locals but a visitor would be correct to query whether he really has a clearance. The reality is that ATC are issuing a clearance, so why don’t they use the standard phrase?

I know this is digressing from the topic but there are enough problems already with poor ELP of ATC around Europe. Not using the right phrases doesn’t help.

Administrator
Shoreham EGKA, United Kingdom

“Radar Contact” is standard phraseology, IMHO

(why was my post deleted?)

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