Using another ILS for cloudbreak
 

In another thread, there was reference to "you can use the [airport 20 nm away]'s ILS for cloud break".

Can anyone explain how this actually works and whether it really is a good idea?

As I understand it, if you get down to minima (on an approach you do not actually want to complete), you continue with the published go-around procedure and you will be in the same position you had been in if this was really the airport you wanted to land at - potentially eventually needing to divert to your alternate.

However, if you do get under the cloud cover, you will (presumably) be relatively close to an airport you don't actually want to land at and, in practice, probably in controlled airspace?
At that point, you break off the approach and 'resume your own navigation', scud running towards another airfield in the vicinity.

Which sounds a bit borderline to me.

Would ATC at the 'unwanted' airport not be slightly surprised by this (ignoring the fact that they'd probably send you the bill for an instrument landing?) and/or will you not be in breach of your contract with the controller?
Or do you inform them from the outset that this is just a 'cloudbreak' approach?

I guess my real question is what you gain by this. If there is a decent ceiling (1500 feet agl, say) , you should not need an ILS to break through the cover. And if the ceiling is low (towards minima), I would be uneasy about the 'false' ILS approach for the reasons above - and then still have the scud running under a low ceiling to do as well...

What have I misunderstood?

Thoughts appreciated.

B.

Perfectly normal procedure although '20 miles away' is pushing it a bit!

I've heard of the Manchester ILS being used by traffic inbound to Woodford when the Woodford ILS was out of service.

We once did an instrument approach to Benbecula with the intention of going around and continuing VFR to Barra. But when we became visual, all we could see in the murk was the Benbecula lights! So we landed there.

Using another ILS for cloudbreak
 

I have flown an ILS into Cardiff to overshoot followed by a landing at St Athan. The short transit was within the military low flying rules and either the radar was out at St Athan or the SRA limits were quite high, can't remember which now.

Using another ILS for cloudbreak
 

When you bear in mind that a 750' cloud base is legal for LL FJ ops the ILS is perfectly feasible as a means of entering low level. You should choose your airport and words wisely though. Shooting an approach into a busy airport with the intention of pootling off to low level afterwards might be a touch inconsiderate.
BV

Sounds like some need to get out a bit more! As Chevvron said, it's a perfectly normal procedure, obviously done with ATC approval where necessary and it needs to be carefully thought out in advance. Obviously, the 1,000 foot rule needs to be adhered to where necessary.

I've had to do this a number of times to get to a landing site in poor weather, perhaps two or three times a year. Some pilots do it quite routinely. Sometimes you get a bill for the approach, sometimes not. If you do get billed you pay up, so no-one objects (some PPRuNe armchair experts excepted, of course, who have obviously never had to do it in the real world). :rolleyes:

Why would you plan to go around on the MAP? If the weather is that marginal, you should plan on landing at the airfield you're doing the ILS to, not trying to continue VFR.

Normally you would break off at a sensible height as soon as you obtain visual references then continue to your destination under VFR.

Do part time towers turn off the ILS when they knock off for the evening ?

HI

first off, I speak of the USA only. NO , nav aids are not turned off at night to save power. We utilize our airports 24 hours a day (noise restrictions aside...but the ILS is still on).


Second off, utilizing an instrument approach (of any kind) at one airport and then proceeding visually to another airport is just fine as long as you coordinate it. It is not marginal as long as you are in compliance with existing regulations. And that you are competent.



Now, what to do ? IS the airport you intend to go to without an instrument approach? IS the wx reported / forecast to be at or above basic VFR (VMC)?

YOU can ask for radar vectors at the minimum vectoring altitude OVER the airport you intend to land at, and if YOU can proceed VFR, advise ATC of cancellation, or request a visual approach and go to the airport and land.

But lets say the ceiling is solid (undercast complete) and you cannot see the airport, but it is reporting 1500 OVERCAST and 3 miles visibility. And so is the airport 20 miles away and it has an ILS. Fly the ILS and ONCE YOU ARE VMC/VFR , cancel the IFR and proceed (with other clearance depending on airspace) to your intended airport.

Even more and niftier things can be done if you properly coordinate and receive clearance for an ILS, and then get a SPECIAL VFR clearance and then proceed in basic vfr out of one airport to the other.


NOW, I don't want to tell you what to do, because if you have to ask on PPRUNE, you probably need some more flying lessons.

So, be careful and maybe find a really good flight instructor/instrument instructor...you know, someone with a couple of thousand hours and have him teach you. And then pay him well because he has to earn a living too.

I agree with Shy. You use such a procedure when you're in IMC, or VMC-on-top, and you know/suspect the cloudbase is below the MVA, MSA or whatever your minimum IFR altitude is at the time. So you can't descend safely below the cloudbase in just any odd random location.

So instead you use the arrival and approach procedure of a convenient airport to safely descend below the cloudbase. Once you are below the cloudbase, you continue VFR to your destination. And if the cloudbase turns out to be too low for (safe, comfortable) VFR, you either fly the missed approach and continue IFR, or you land at the airport that offered you the instrument procedure in the first place - in effect a diversion because your destination cannot be reached VFR.

Obviously if you only break out at minimums (typically 200 feet on an ILS) it would be pretty stupid - not to mention illegal - to continue for another 20 miles under the 200' cloudbase to your destination. But if the cloudbase is at, say, 1000 feet, then this method is very convenient.

FWIW it was me that posted the original comment about using the Glasgow ILS for cloud break to Cumbernauld.

I've done it several times and the original advice to do it came from Cumbernauld airport.

As has been posted already, you just ask the controller you are already talking to and they will arrange it for you quite routinely.

On one occasion, I tried to do it and couldn't break cloud high enough to be safe and ended up actually landing at Glasgow. Both landing fees and handling costs were reduced by 50% under the Strasser scheme but still hurt! Both ATC and the handling agent were very good though.

Do part time towers turn off the ILS when they knock off for the evening ?

Even if they do leave the ILS on, it may not be where you expect it.

Some airport have the same frequency of the ILS for both runway directions (e.g. EGGC 23R/05L), so they DO switch off the ILS of the direction opposite of the "active" runway.

Skeeve - if the airport is closed how can you have an "active" runway. It may not be co-incident with the prevailing wind, that's all. Thats one of the reasons you ident the ILS, to make sure you know which end of the runway the ILS is selected on.

And like others here - as an ATCO I've offered cloudbreak ILS's (nobody's ever received a bill) and as a Pilot I've requested and been given them. Very useful with cloudbases just above circuit height at destination airfields. Just make sure you know the topography for transiting between the two.

airports are rarely if ever technically closed. air traffic control tower might be closed, in which case you use common traffic advisory freq and good luck

air traffic control rarely decides to close an airport, they can act as agents to the managing authority as if they want to plow the runway for snow and close the airport.

atc may have a letter of agreement/MOU that they will declare the airport closed if CRAF has deployed to rescue/handle fire of a crash as the CRAF could then NOT respond to a second crash.

IT is however possible that the runway lights might not be on the step you wish them to be and clicking your mic on CTAF might (if equipped) change the setting.

go find a nice , competent CFII and good luck

Not many UK airfields have RT controlled lighting. In fact I can't think of any, although I know of a few helipads that do.

In the USA yes, but Europe is totally different - airports have hours of operation, and are closed outside of those.

ASRAAM, what aircraft were you flying- purely out of interest? Ta.
CG

But does that mean you are not allowed to shoot the approach after hours for cloud break then continue on to your home strip

What you do, in class "G" airspace, is your business.

Do part time towers turn off the ILS when they knock off for the evening ?

I know the one that matters to you Piperboy. Yes, Dundee does.

D.O.

Using another ILS for cloudbreak
 

Thanks DO, so the next question would be the leuchars ILS can that be used if it gets you down to visual prior to entering there immediate ATZ but within the surrounding MATZ ?