Correct me if I'm wrong but I would assume that if you're cleared for the ILS, you are implicitly cleared to enter the ATZ, even though you fly the ILS for cloud break purposes and not with the aim of an eventual landing.

There's just too many "what if's" if you get a clearance like "Cleared for the ILS approach, report VMC, do not enter the ATZ". What happens if you do not become visual before entering the ATZ? You are most likely below the MSA now so you can't simply circumnavigate the ATZ. Something that would be tricky with a moving map GPS, and almost impossible without a GPS anyway. Obviously you can try to climb above the ATZ but practically speaking that would mean that the go-around decision needs to be made at 1200' or so (*) - which makes the whole cloud-break procedure pretty pointless.

(*) Assuming a standard 3 degree ILS and a 3-nm, 1500' ATZ. If you want to fly the ILS to the furthest extent possible, you need to go-around at about 4nm/1200' at the latest, in order to be at or above 1500' at 3nm.

Only getting down to a 1200 ft MDA would probably work fine as I would need at least that minimum to navigate terrain between the ILS field and my intended destination strip. So if not visual at 1200 and as the approach is over the sea, just level off , hang a 180 climbing back on top and find somewhere else to land.

From time to time aircraft inbound to us use the Dundee ILS and break off at low level when VMC. They need to know the low level route from there as direct will not usually work .

The same is possible at Leuchars but again the low level route would need to be planned in advance. They are also able to offer a cloudbreak over the sea.

Leuchars are no longer 24/7. I don't know if they switch off their navaids.

D.O.

How does that work?

UK ATZ's are 2000ft and either 2 or 2.5nm radius dependent on runway length (1850 metres being the deciding figure).

Also - you can't be cleared for the ILS if the aerodrome is closed, which is where the thread is at the moment.

They will vector you offshore, remind you that you are responsible for your own terrain clearance and let you get on with it.

Reliable GPS has made this almost almost redundant.

D.O.

JUST a piece of advice...if you are doing a cloud break via ILS, I would think doing the LOCALIZER only apch would get you down faster if you like and then you will have more time to look at the wx conditions.

I don't understand that one! Are you suggesting flying below the glideslope???
D.O.

I think that's actually what he meant.

On an ILS you use the glideslope for vertical guidance. Easy but out of technical necessity the glideslope is a straight (sloped) line leading to a constant descent.

When you do a LOC/DME or VOR/DME approach it is perfectly feasible to have step down altitudes during the approach which let you descend earlier than what's technically possible on an ILS approach. For instance, a normal ILS requires you to be at 2000' AAL at 6 nm out. But a VOR/DME approach may consider it perfectly safe to descend to 1500' at that distance - obviously if terrain allows.

So with a LOC/DME or VOR/DME approach you may well be able to safely descend earlier, indeed below the ILS glidescope, and get into VMC earlier. Whether that really makes a practical difference, I don't know. Plus, ATC will probably assign you the ILS approach out of habit anyway, even if in this particular case a LOC/DME or VOR/DME would be more convenient for you.

thank you backpacker for understanding.

WHAT I DO NOT UNDERSTAND is how someone with a full instrument rating would not understand this.

I STRONGLY ENCOURAGE YOU TO FIND A REALLY GOOD INSTRUCTOR with LOTS OF REAL INSTRUMENT FLYING EXPERIENCE dear OP!!!


the glideslope takes you to the runway (loc too). but you are going to a completely different airport SO GET DOWN AS QUICKLY AS YOU CAN (within published , safe limits)

then you can start looking for your other airport.

really, how don't you understand this?

Thanks Backpacker, I do understand there is an opportunity to descend slightly earlier on a LLZ app but I don't think it is a good idea to make a rush for a break as there is little advantage to be had.

Glendalegoon,
Chill. I was origionally replying to Piperboy as I am familiar with the airport he would use. I was emphasising that his local knowledge would be required as the airport in question already has a steeper than normal glideslope and there would be no risk of him seeing his destination at that point anyway.

D.O.

real life flying means finding a break , knowing where you are and then going for it.

if you don't take the first break, there might not be a second.

this is a little like barnstorming, but either you know what you are doing or you become extinct.

a piece of advice to the original poster.

as you seem unsure of this concept, please, only try it in good wx before you do it in bad wx. in this way, you can understand the communications, coordination and study the terrain in good wx. you can also try the concept of using the localizer only approach.

and if ATC clears you for one apch, advise them you plan to do the other apch and get an amended clearance.

good luck, fly safe, support your local flight instructor (professional).