So what's the difference, under Rule 40, between flying down an ILS and using an off airways VOR or NDB for navigation outside controlled airspace?

I believe tori chelli has got it right.

If the airfield is closed, then there is no atcu to authorise anything other than the notified procedure.

The airfield operator has to publish when a service is available, but outside those hours they are not required to turn the facility off, at least not in the 2 approvals i've read.

The UK and the US are not all that different as I read it.
In the US, you can carry out an approach using the aids of a closed airfield without any ATC clearance at any time if flying VFR. Exactly the same as in the UK :ok:

In the US, if you are IFR, you need an ATC clearance (from the Tracon or Center if the airfield ATC facility is not available). In the UK, you also need an ATC 'clearance'. The only difference is that the Area Control Centres in the UK can't give you one so there is no possibility of legally making an approach in IFR at an airfield which is closed (except with special procedures agreed with the CAA by individual operators).

Scott or West Coast, correct me if my simplistic view is wrong please :ok:

Rule 40 makes no distinction between VFR and IFR.

Bookworm

You have to apply lateral thinking to get to a VFR exemption from the Rule ;)
Rule 40 states:

So if we jump to Rule 31 :

So, if someone files IFR with any portion of flight in CAS, but then cancels to go VFR (perhaps doing so with an En Route ATC agency or a FIS service, not necessarily the airfield ATC unit), they do not need to comply with Rule 31 Para 3 (a) but only Rule 31 Para 3 (b). By complying with the relevant part of Rule 31, they can be exempt from Rule 40 :ok: It may not be the intention, but the relevant part of Rule 31 doesn't state that you have to remain in CAS at the point where you are using the navaid, does it ??

In other words, I could depart from Bristol IFR (in CAS), comply with relevant clearances until clear of CAS, cancel IFR and go VFR with London Info, and then make a VFR approach using the navaids at Shoreham (which is closed). It would all be down the the legal interpretation of what would be an 'appropriate ATS unit' to cancel the IFR plan with, thus allowing me exemption from Rule 31 Para 3 (a) and subsequently Rule 40. I would argue that London Info is an 'appropriate' unit to do so with. I suspect the CAA mean it to be an appropriate ATS unit related to the navaid, but as this is not implicitly stated, it is arguable in court.

For someone flying VFR the whole way, or flying IFR wholly outwith CAS before going VFR whilst still outside CAS, it is perhaps not as clear cut, but there are certainly things a good aviation lawyer could pick up on to argue with :D

Sounds to me it would be easier to just go ifr :)

PPRuNe Radar... I think I managed to follow your logic, convaluted though it was. One question, just because there is a legal defence (albeit questionable as you yourself admit), do you think that makes the practice of such a manouevre sensible in light of the cautionary tales that have been posted?

Pprune Radar - sir :)

Most of your answer referred to IFR in CAS as detailed in Rule 31. I still maintain that the law is being followed if you fly the notified procedure to an out-of-hours airfield in the FIR (ATZ not existing out-of-hours) if the navaid is still powered up and idents correctly. I still refer to the CFD VOR which, if memory serves, is an en-route navaid operated by The Authority, but happens to have an airfield approach procedure stuck onto it.

Discountinvestigator
I still think a CAA VOR facility operating H24 covers Art 104 1)...as to conditions specifying use for approaches under 104 3) I couldn't say:\

Goddamit...thank you, it's not often someone thinks I'm right :D :D

I'm not suggesting it's clever, or that I'd want to do it, but for theory's sake...

Perfectly safe in respect of the US way (which I was defending as being not too disimilar to the UK) and also the UK.

In VFR (and thus VMC) you can see the ground. Using an aid does not prevent that. Legally whether you can use an aid which no one can check up on whether you did or not is another issue. I think that is the same for the USA and the UK (by inference).

In IFR, the US requires you have a clearance from someone. I don't know their rules well enough to say if there is a VMC differential whilst under IFR.

In the UK, under IFR you need an ATC clearance, except in the specific occasions mentioned in the ANO. These conditions are when you are flying in IFR and then switch to VFR (and thus VMC) or when you can fly in uninterrupted VMC (remaining IFR) in CAS. Again, using an aid does not prevent you seeing the ground.

So both are perfectly safe systems in my opinion.


IFR and IMC in UK = No go without ATC clearance. Only available from airfield ATSU.
IFR and VMC in UK = OK, if you are in CAS, or cancel IFR plan.
VFR and VMC in UK = OK at all times.

Interesting thread, from a pilot's point of view. Especially from an instructor's point of view - I often have reason to fly instrument approaches in VMC (for training) and it's good to know what I can and can't do.

Can I ask for your thoughts on the following related issue? A hypothetical airport in Class G is occassionally short of staff, and is not able to provide any form of approach control service for short periods due to not having appropriately qualified controllers.

If I want to fly an instrument approach, in VMC, the tower controller is not able to clear me for the approach because he is not qualified to do so. But he is happy, and might even pass me traffic information, if I inform him that I will be "general handling in the overhead at 3000'" and I then fly something which looks suspiciously like a hold. Likewise, I can then inform him that I will be "general handling to the east of the airfield", and then that I am "6 mile final" for the westerly runway, from which point he will clear me to land, touch+go, or low approach and go around as appropriate. Has anyone broken any rules?

How about the same situation in IMC, notwithstanding the fact that I have no method of avoiding conflicting traffic?

FFF
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Having previously worked at such an airport it's not as hypothetical as you infer ;)

VMC - Provided neither of use any words that infer that an instrument approach aid is being used then no problems at all - because you're not are you. Once you say something (remember - it's all taped) then you drop yourself (and possibly said ATCO if they 'go along' with it) in the pooh.

IMC - the same applies. After all, he's not in the aircraft - you are. Therefore said ATCO, although the weather conditions they report might intimate IMC, doesn't actually know you're IMC where you are.

It's a matter of conscience really.

Tori Chelli
Basic flaw in your post ..... the CAA don't operate any navaids :p

However, I agree with you that it could be interpreted that flying an approach published in the AIP (regardless of ATC availability) might comply with Rule 40. I need to take counsel on that though ;)

I think we can agree the US experience demonstrates that the risks of using aids without a clearance, particularly in VMC, are quite limited. Other than that, I think I'll refrain from the suggested "lateral thinking". ;)
Rule 40, and in fact much of the UK attitude to IAPs at smaller airports, is both vague and hopelessly out of date.
i.e. anything's legal as long as you don't get caught? ;)

PPRUNE Radar Don't know whether this makes much difference to your argument but ‘Appropriate air traffic control unit’ is defined in the ANO as "in relation to an aircraft either the air traffic control unit serving the area in which the aircraft is for the time being, or the air traffic control unit serving the area which the aircraft intends to enter and with which unit the aircraft is required to communicate prior to entering that area, as the context requires". The phrase "with which unit the aircraft is required to communicate" might be a problem but I agree that it all comes down to an interpretation.

There's an interesting thread elsewhere about the effect of interference (by vehicles) on ILS. An interference will result in the ILS unit being unusable and immediately switched off.
Presumably before entering the localiser our pilot (who will not have advised ATC) will have morse identified it. If there is then a problem with the ILS during his approach there will be no way of the ATC advising the pilot of this fact if they (the ATC) are unaware that the pilot is using the ILS.

If the ILS gets switched off he's going to get flags up pretty smartish - he will be left in no doubt that the ILS had gone off, ident or no ident.

Just a minor point here, yes, they can transmit both at once, at least over here in germany. Often enough there is a relevant remark on the ATIS that the opposite ILS is transmitting and therefore automatic landings are not allowed. Thats the only restriction though, normal approaches can be done.

Reason seems to be that each ILS (LOC and GS) needs to transmit a certain amount of time per month/quarter to retain its CAT III status. In the case of low visibility procedures becoming active the opposite will be of course switched off to allow automatic landings.

Pprune Radar

I wasn't sure whether to refer to CAA or NATS engineering...either way it's a specious point because I'm talking about en-route navaids notified H24 that also happen to have airfield approach procedures attached to them; irrespective of whoever operates them :hmm:

Can't fly IFR/IMC without a clearance? What if I get airborne from my (lit) strip at night in VMC (& IFR), fly into IMC while terrain safe and then fly the procedure out-of-hours to MDA, go-around back to MSA and fly back into VMC?

I'm looking at Benbecula, Biggin, Cranfield, Ronaldsway, Southampton (couldn't get Sumburgh to come up on the AIP site:ugh:) & Wick...what would anyone out there think if a pilot shot the published approach out of your hours using the en-route navaid? :hmm:

Tori

PPRUNE Radar;

You are indeed correct in your inference to the US way of doing it. Now, if you are IFR it doesn't matter if you are VMC or IMC, you are still IFR and need some sort of a clearance, BUT, if you are VMC and not in class B, you can just cancel IFR if you aren't getting what you want <G>, and go on your merry way.

Sorry it took me a bit to respond. But we have the green and white flag with the red dragon in the middle flying from the house right now and are entertaining guests at the moment from that far away land <G>.

Take care

Scott