ATC Requirement for Instrument Approaches

[Willow04]

Hi all,

Got a question here that I'm hoping some of the ATCOs might be able to help with -

Having recently read about Shoreham introducing the first approved RNAV GNSS non-precision approach for GA, I was interested to know exactly why the CAA state one of the requirements of an airfield for having such an approach procedure is that it must have a full Air Traffic Control Service and NOT a Flight Information Service or Air/Ground Service.

I assume it must have something to do with providing separation for the IFR traffic flying the approach, but the specifics are a little hazy. I can think of a hundred reasons why having an instrument approach procedure at annything other than a full ATC unit unit is a bad idea but I am really struggling to find anything in writing as to exactly what the rules are.

If someone could point me in the right direction I would be very grateful indeed!

[Spitoon]

The legal reference is Article 103 of the ANO 2005. As I understand it, this rules originated many years ago when two aircraft either collided or got very close when trying to fly an IAP without ATC. Not all States have the requirement for an approach control service. Note that the legislation doesn't require an aerodrome control service but, it seems, the CAA is now introducing such a regulatory requirement for GNSS-type approaches if what you say is correct.

For some reason the UK/CAA has trouble distinguishing between the function of an IAP, to get from in/above cloud etc. to a point where a visual landing can be completed, and and the function of ATC which is to provide separation between aircraft (whatever they are doing).

[Willow04]

Ah Spitoon, you absolute hero. That Article 103 was exactly what I've been looking for, for the past x number of weeks.

The reason I was asking is that I work at a FIS unit airfield, the management of which is adament that they will introduce a non-precision GPS approach much the same as Shoreham.

Of course, at first glance to me it seemed ridiculous that you could have any kind of approach procedure at an airfield without a control service - not too long ago I witnessed a Bulldog completely cut up a BAe 146 by turning final way too early, which resulted in the 146 having to go around. Having this happen during the final stages of the approach procedure would only end in tears.

Non-precision GPS approach....at your discretion....no known traffic to effect...

[2 sheds]

While it was obviously written without GPS approaches in mind, Art 103 refers to equipment provided, in effect, by the aerodrome operator!

Should they wish to continue along this route, Art 104 might be more applicable.

2 s

[tori chelli]

Spitoon

you may be able to answer this one...what law are you breaking (if any) if someone wants to 'practise' a let-down procedure out of aerodrome hours? I'm thinking of the likes of Cranfield, Southampton, Newcastle where the VORs are H24 but the airport is closed. The beacon is in tolerance and idented, the procedure is valid and flown correctly. There's no airspace to infringe (it closes with the aerodrome). Fly not below 500ft agl.

My gut feeling is that this isn't sensible, but I can't see where to justify that feeling in Law. Thoughts?

Tori

[eyeinthesky]

Don't try to let down on the NEW VOR, even if EGNT is closed: it's withdrawn from service permanently!

[Spitoon]

Spitoon

you may be able to answer this one...what law are you breaking (if any) if someone wants to 'practise' a let-down procedure out of aerodrome hours?Hi tori, only just spotted your question.

Hmmmm, this is a slightly tricky one I think. I'm not a lawyer so this is just my take on it but my understanding is that it's not specifically proscribed if certain other rules can be complied with. It probably comes down to Rules 22 and 24 of the Rules of the Air Regs. Rule 22 says you can't use a radio nav aid unless you comply 'with such restrictions and procedures as may be notified in relation to that aid', so the first thing to look for is any entries in the AIP that say 'not for use without XX ATC permission' or 'not available outside hours of operation of XXX ATC'. If there's nothing like that, then you can probably use the signal that is available.

Next, if you are doing a practice instrument approach then rule 24 applies. This says you have to tell the appropriate ATC unit that you are doing a practice approach - note, it doesn't say you need permission.

Here's the definition of 'appropriate air traffic control unit' - 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. So, probably, if the ATC unit that 'looks after' the aid is closed it cannot be serving the area - but beware, because of the way that ATC is done in the UK, there may be another ATC unit that also serves the area. If things go pear shaped you might just find yourself being quizzed as to why you didn't tell YYY ATC what you were doing. Remember also, although it is less common these days that it was in the past, although an airport may be shown in the AIP as closed, ATC might still be there (and might not be NOTAMed as such).

A couple of final thoughts. Navaids are monitored by ATC (admittedly to different degrees) - if ATC isn't there there's not likely to be any monitoring that the thing is working properly. That said, the equipment should switch itself off if it goes outside operational parameters.

And, of course, don't go into any airspace for which a clearance is required without getting that clearance - so check NOTAMs for extensions of opening hours.

So, in summary, I think you can do it in certain circumstances - but someone else might easily interpret the legislation differently.