Precision approaches at unmanned airports

[Goldfish Jack]

I was just wondering whether a pilot could answer the following question for me:

"ASSUMING THAT THE TOWER IS NOT MANNED, HOW CAN A PILOT COMPLETE A PRECISION APPROACH, IF THE ILS IS NOT MONITORED?"

We have just been having a discussion about this and were wondering if it could be done, as where we work, there are airports that have no ATS service, ie late at night, yet the ILS is left on. As I understand it, the ILS is supposed to be monitored, by ATC, to ensure reliability and integrity and that nothing will fail, whilst it is being used. Who does this after hours and therefore, how do you know, as a pilot, that the ILS is radiating correctly?

I would suggest that if the ILS is not monitored, surely one should be doing a non-precision approach?

Thoughts and views would be appreciated.

[Captain Stable]

Excellent question.

My suspicion would be that either (a) you can't or (b) you can conduct an ILS with non-precision aids tuned and idented for backup, to non-precision minima.

But I may well be wrong.

I'm going to copy this thread across to the ATC forum for any input they might have.

[FWA NATCA]

Goldfish,

I vector aircraft on a daily basis to airports without towers for an ILS approach for which I don't monitoring. I rely on pilot reports if there is a problem with on of these ILS's. Flight Service or maybe the local FBO may monitor these but we don't.

Mike
NATCA FWA

[Timothy]

I don't know whether it is legal to fly an ILS when there is no-one in the tower in the UK, I believe not, but I think that the least of my worries would be the liklihood of failure of the ILS to be monitored.

We carry plenty of other gear to give us a pretty good idea of whether we are the right place at the right height (not least GPS, which in many case paints the final approach, and always give range for checking height.)

I would be more worried about what I was likely to encounter on the runway. Presumably if I needed to shoot an approach, conditions are IMC, and if there is no-one home presumably the RVR could be anything, and we all know that if we are landing at low RVRs we will not be able to see an obstruction on the runway in time to avoid it.

Timothy

[604guy]

It is something that occurs with some regularity in Canada. The monitoring can be done remotely at another site. System sends an alarm and aircraft are no longer able to conduct that approach procedure until the problem is cleared. Not sure how this might apply with UK regs though.

[Barnaby the Bear]

On a similar note. Unmanned is one thing, but how doe's it work with FISO units. I.e Lydd are/or have fitted ILS but are FISO ATS.
Just interested how the set up works?
As I understand it FISO's give as it suggests a FIS and 'control' A/C on the ground. So what are the procedures?
Or is this planning towards full ATC? :confused:

[Chilli Monster]

Barnaby

To provide any form of instrument approach in the UK you need ATC with a validated approach controller on duty. Lydd are installing the ILS with a view to going full ATC - that's the only way they'll be allowed to use it.

I'm with Timothy on this one. Remote monitoring in countries that allow it is fine, but the runway incursion threat would be my main worry. To have that plus an unmonitored ILS starts throwing in too many variables in low vis conditions.

[Goldfish Jack]

Thanks for the replies.

The ILS is not monitored at all and I was wondering what the (legal) implications are if one does the ILS and ends up somewhere except on the runway !!

Tim, you raise another valid point - having done the approach, in low vis and you are landing at an unmanned airport, you quite rightly point out that you will not be able to overfly the airfield and have a (visual) inspection of the runway, so there could well be something on the runway which you will not be able to see.

Me thinks the easy option is not to go to that airfield at all and go somewhere else, or wait until the airfield is manned again!

Captain Stable also raises a valid point - maybe the option is to do the ILS but using the NPA minima??

And I always thought this job was so easy, thats why I chose to do it!!!!

Thanks for the input and replies - much appreciated

[TC_LTN]

I believe the requirement for the provision of an ATC service comes from the following taken from the ANO;

In the case of an aerodrome (other than a Government aerodrome) in respect of which there is equipment for providing hold ing aid, let-down aid or approach aid by radio or radar, the person in charge of the aerodrome shall: (a) inform the CAA in advance of the periods during and times at which any such equipment is to be in operation for the purpose of providing such aid as is specified by the said person; and (b) during any period and at such times as are notified, cause an approach control service to be provided.

[055166k]

I'd put the question to the airport authority, and through them to the Regulating Authority. Depending on your type of operation perhaps an exemption could be secured, using revised minima. On a wider point.....if the ILS is left switched on... is the airport operator inviting its use and therefore sharing liability in any outcome stemming from its use? Of course in a genuine emergency the availability of the ILS whether monitored or not could be a lifeline......but I'm glad I'm not a lawyer.

[Scott Voigt]

Glad that we don't have to have someone on the ground at all the airports here that go IFR and have IFR approaches. If we did, we would bring out system to a stand still... Shoot approaches all the time to airports down to minimums and no one around...

regards

Scott

[NorthSouth]

Flying an ILS (or other IAP) at an airfield with something less than full ATC service is not illegal in the UK but can only be done privately, i.e. if the airfield never has full ATC then the procedure will not be published in the AIP but could be flown by private arrangement/approval (this is the case with IAPs at airports in the Scottish islands where there is only AFIS).

However this is all about to change. The CAA consulted last year on making it illegal to fly an unapproved IAP. Here's the CAA's summary of the proposed changes:At present, only those Instrument Approach Procedures (IAPs) which have an associated Approach Control Service provided by an Air Traffic Control unit may be notified in the UK Aeronautical Information Publication (AIP). Whilst an Approach Control Service will continue to be the norm for control of traffic flying the majority of IAPs, the CAA intends to amend Article 90 of the Air Navigation Order (ANO) and associated Civil Aviation Publications (CAPs) to improve awareness of the presence of IAPs and thus safety. These amendments will allow certain IAPs to be notified where there is an Aerodrome Flight Information Service (AFIS) unit or where the Air Traffic Control unit is providing only an Aerodrome Control Service. Such units will be subject to approval by the CAA. These measures will affect some ATC and AFIS units at aerodromes and also individuals currently using non-notified IAPs. Flying an IAP not approved and notified by the CAA will be prohibited.