GPS approaches to uncontrolled airfields?

[Contacttower]

As previously discussed Shoreham is hopefully to receive the first non-precision GPS approach on November 20th. CAA link here. (http://www.caa.co.uk/application.aspx?catid=14&pagetype=65&appid=7&mode=detail&nid=1676)

However thinking about possible expansion of GPS approaches across the UK something which for me is a real show stopper is this....

The requirements state that an airfield must have:

· A CAA licence.
· A runway meeting the physical characteristics required for an instrument runway – this covers the runway strip width, its clear and graded area, surface markings, holding points and lighting (if used at night). The runway is not required to have an instrument approach system already in place.
· An air traffic control service – not Flight Information Service or air-ground operator.

Is there any likelihood that in the future the CAA will change its attitude to airfields needing full ATC for an approach?

[Spitoon]

Try asking them. I know that a few years ago there was a proposal to permit instrument approaches at airports with a FISO but I don't know what happened to the idea. The details used to be on the CAA website - but no longer. The website says you'll have to use a FOI request to find out more info. Spoke to a lady in the ATS department a while back who was dealing with it all but it didn't sound like there was much progress.

[IO540]

There are some examples of instrument approaches to runways without ATC. I recall there being one at some Scottish island, but as with all such examples this was not a public approach; it was approved (by the CAA) only for a specified commercial operator. There are many such "private" approaches - pick any busy GA airfield with a based commercial operator (say an air ambulance) and with a nearby navaid, and there is probably a private approach there.

The requirement for full ATC is what keeps GPS approaches all but irrelevant, IMHO.

ATC is hugely expensive - of the order of £500k-1M/year just for daytime cover. Whether one likes it or not, most GA airfields would much prefer no ATC because they cannot recover the cost through any extra services. (Same goes for the fire service, BTW).

If the ATC requirement was lifted, GPS approaches could be introduced, US style, at the many GA airfields which are currently unusable in UK's frequent warm front conditions.

But this would require some kind of traffic sequencing to the approach (to the IAF).

One could have self-announcement but this would really grate against the "European way of doing things".

The USA does it by getting a nearby radar controller to schedule the traffic onto the approach. This works fine but in the UK the radar unit would invoice the airfield for the service :ugh: For example, Thames Radar invoices Biggin Hill for the radar service - I guess at some flat annual rate which is why the Biggin plate says the procedural approach is not available unless Thames Radar is unavailable - they want to get the maximum value for their money. This billing would make the whole thing totally uneconomic to most GA airfields.

So.... no likely progress.

Another thing about GPS procedures is that you need an approach approved GPS. This is very rare in EASA land although a lot of N-reg planes have one. Until recently, it was an EASA Major Mod but they seem to have issued an exemption recently for the specific case of a flight manual supplement authorising approaches, so it is just some £hundreds now, reportedly.

Whereas with conventional approaches, you can fly them unofficially using an IFR GPS and it doesn't have to be specially approved.

Currently, most (all?) airports that have full ATC already have a conventional IAP, and these IAPs either exist in the GPS databases, and can thus be flown by tracking that "overlay" using the GPS or using the GPS's OBS mode. There is no regulation (for private flight) prohibiting this practice and it is far safer than say flying an NDB approach using the ADF. Airlines do this already - they often fly NP approaches using the FMS navigation but they check the ADF at the top of descent for example, and this is a CAA approved procedure. You are flying the published track but using the GPS for guidance.

So, perversely, the present situation is actually more useful (to the vast majority of private pilots) than the full blown GPS approaches........

At some presentations I went to a while ago, the CAA did say they were examining the issue of approaches without ATC, but nothing happened, and I think nothing can happen unless the funding arrangement (for the scheduling service) is completely changed, or FISOs are authorised to provide a procedural service which is another huge chestnut since they have no authority to "control" airborne traffic.

[Fright Level]

There is no regulation (for private flight) prohibiting this practice and it is far safer than say flying an NDB approach using the ADF. Airlines do this already - they often fly NP approaches using the FMS navigation but they check the ADF at the top of descent for example, and this is a CAA approved procedure. You are flying the published track but using the GPS for guidance.

A small correction IO, when flying an NDB approach, we don't check the ADF at the "top of descent", we monitor it throughout the approach as per a standard NDB approach. The autopilot is connected to the LNAV track, which is derived from the FMC database and the aircraft position is determined by GPS input (much the same as a 430/530 set up). The primary means of navigation is still the ADF and tracking must be monitored throughout the whole approach (as well as monitoring the ident). Normal errors are allowed for the flying of the approach, but as expected the GPS nails the approach with the needles never deviating more than a couple of degrees, therefore within limits for that approach. Technically you're flying the NDB approach but the autopilot is flying a copy of the published approach track with the position fixed by GPS. The CAA don't need to approve it as we're flying a monitored NDB the whole time.

What the CAA have recently approved are RNAV approaches (eg LHR 27L) which do not require monitoring of any ground based aid to complete the approach.

In my SPA IR, I was encouraged to fly the GPS based approaches and monitoring the ADF needles ensuring they stay within limits (which of course they do). The ADF remains therefore the primary means of navigation.

[IO540]

The primary means of navigation is still the ADF and tracking must be monitored throughout the whole approach (as well as monitoring the ident).Thank you for the correction, FL. What I said was based on at least two airline pilots' accounts (two different airlines; yours is evidently different) and they certainly check the ADF only at the TOD.

My Q is: what do you do if the ADF deviates by more than X degrees (what is X)? Do you go around? If you did, you would go around every time thereafter because NDB radiation pattern errors are constant except for the day/night cycle. I am sure you need to be pragmatic about it :) I know of NDB approaches where if you fly the GPS inbound precisely (coupled) and watch the RMI, the ADF error rises to some 30 degrees.

[Fright Level]

I'm not sure what your airline friends mean by "TOD". Do they mean leaving the platform altitude on the approach or the true top of descent from cruise. It's essential to always monitor/identify the ADF signal throughout the approach when using it as the primary means of navigation as there are no fail flags with an ADF receiver. Pretty standard SOP for any airline I would have though. Although the 744 has and electronic ident function on the nav displays (it shows the decoded morse), it's still our SOP to listen to the NDB transmission to promptly detect any failure of the aid. I doubt you could properly identify an NDB from a typical jet TOD point as you'd be 100 miles away. Most NDB's only have 10-25 mile range so how your friends airlines imagine they can or should only identify them at TOD is bizarre (and potentially dangerous). If the NDB failed whilst they were tracking it, how would they ever know?

I've never seen NDB errors of 30 degrees. I've only ever seen them waver when there is a local active CB cell. Short term deviations are acceptable particularly when backed up with a moving map display but if there was a deviation of the order you mention for more than a few seconds, I would certainly go around.

To qualify all of this, I'd say 99% of my jet NDB approaches have been in the sim, not the real world, but we still have SOP's that dictate how they should be flown. If they are the primary approach aid, then tolerances (5 degrees) etc must be adhered to regardless of what a GPS generated map tells us. Some pragmatism is allowed in commercial aviation, but not much. Moving maps tell such a compelling story that it would be easy to be sucked in when something was set up wrongly.

[IO540]

One was a 737 pilot and the other was an A340 pilot.

They appear to be flying procedural NDB approaches (outside the UK) so the "TOD" would be the FAF - the start of the final inbound leg on which you are tracking the NDB inbound.

[Fright Level]

Just a question then, how far would your airline mates fly with the ADF needle pointing straight ahead once they last identified it at the FAF and "switched off"? I'd suggest this is an extremely dangerous practise.

Can't find a reference but there was a recent serious incident in Africa where the map provided a compelling image and a VOR approach was flown without reference to the raw data and map shift nearly caused the loss of a hull.

I've PM'd you an excerpt from our operations manual on the subject of NDB monitoring.

[IO540]

Thank you for the PM, FL.

Obviously I am not an airline pilot but I guess the attitude to this must depend on the exact situation, and also on the likelihood of "map shift".

Let's say you have navigated to a standard-ish 4.5D FAF, and you are pretty confident that's where you are. Navaids all checked, including the NDB/ADF. And you are established on the final approach track at the FAF.

There isn't much that can go wrong after that, just by flying the right heading. The distance to run is only 4.5nm minus whatever the distance at which you are supposed to be visual - typically around 2D so you have only 2+nm left to run. Obviously you will have a pretty good idea of the wind by then too. The ICAO procedure design criteria are pretty generous on NDB approaches. It seems over the top to require a constant monitoring of the ADF, during this very short distance and time.

Also, if "map shift" was that common, the whole concept of BRNAV and PRNAV would go out of the window. Planes would be wondering all over the sky. Your INS should be pretty stable for these short periods.

You can get a map shift with a pure GPS system if you are descending between mountains. But not in open terrain. Maybe Kathmandu but that is a VOR approach which should be accurate enough.

The proof of the pudding is in America, where millions of pure-GPS approaches have been flown, by a wide variety of operators ranging from private pilots to jet transports, and they have not identified systematic problems.

[Contacttower]

For example, Thames Radar invoices Biggin Hill for the radar service - I guess at some flat annual rate which is why the Biggin plate says the procedural approach is not available unless Thames Radar is unavailable - they want to get the maximum value for their money. This billing would make the whole thing totally uneconomic to most GA airfields.

Do you know how much they get charged?

Surely if enough people used it the airfield could simply pass on the cost to the users.

[Fright Level]

Map shift is very common in non GPS IRS aircraft in countries where ground based aids are few and far between and/or improperly calibrated. My airline regularly suffered from false localiser captures where the IRS based track turned the plane onto the supposed localiser track which was offset to the actual localiser. Quite tricky to spot and it resulted in our SOP being changed so that localiser courses could only be established from a heading, not an RNAV track. This is going now GPS is more common.

Let's say you have navigated to a standard-ish 4.5D FAF, and you are pretty confident that's where you are. Navaids all checked, including the NDB/ADF. And you are established on the final approach track at the FAF.

There isn't much that can go wrong after that, just by flying the right heading. The distance to run is only 4.5nm minus whatever the distance at which you are supposed to be visual - typically around 2D so you have only 2+nm left to run. Obviously you will have a pretty good idea of the wind by then too. The ICAO procedure design criteria are pretty generous on NDB approaches. It seems over the top to require a constant monitoring of the ADF, during this very short distance and time.

What you are suggesting is flying (what is likely to be below the MSA) on an approximate heading with no visual reference nor positively identified ground aid in a direction you cannot be 100% sure of. Sure, 2 miles may not be a problem, and in fact this scenario is common where the NDB is out on the final approach, not on the airfield. During the approach as you pass overhead the beacon, all you can do is maintain a heading and (often) start the final descent whilst the needle is spinning 180 degrees and you're not properly established inbound. But rules is rules. In public transport operations, we don't eyeball anything or carry on another 2 miles without positive guidance because we think we know where we are. Safety records of decent airlines bear out the importance of this very conservative method.

Also, if "map shift" was that common, the whole concept of BRNAV and PRNAV would go out of the window. Planes would be wondering all over the sky. Your INS should be pretty stable for these short periods.

Map shift is usually caused when the a/c has been flying with sole reference to the INS/IRS and then comes within range of the landing airport aids and resets it's position.

You can get a map shift with a pure GPS system if you are descending between mountains. But not in open terrain. Maybe Kathmandu but that is a VOR approach which should be accurate enough.

RAIM is more critical in commercial ops.

The proof of the pudding is in America, where millions of pure-GPS approaches have been flown, by a wide variety of operators ranging from private pilots to jet transports, and they have not identified systematic problems.

We don't fly pure GPS approaches in the 744. We fly RNAV final approaches (eg JFK Canarsie overlay) but this is using the triple IRS system updated with twin GPS positions and a pair of traditional ground aids (from the best resolution DME/DME to VOR/DME and VOR/VOR calculations). We manually set lateral tolerance limits into the FMS and an exceedance of these on the approach (Unable RNP message) means immediate attention with consideration to a go around.

[IO540]

FL - thank you for taking the time to type up all this. I don't think we disagree on anything. Map shift is bound to happen with INS because of the gradual accumulation of errors - even FOGs are not perfect.

However, I did not say

What you are suggesting is flying (what is likely to be below the MSA) on an approximate heading with no visual reference nor positively identified ground aid in a direction you cannot be 100% sure of.

because you are getting continuous guidance with the GPS, and the loss of GPS function is normally pretty obvious. Especially with RAIM, which is anyway mandatory for GPS approaches.


Surely if enough people used it the airfield could simply pass on the cost to the users.Probably not - the % of IFR traffic is generally too small. At Biggin there is a lot of high value (bizjet) traffic but the average GA airfield would not have enough.

I don't know what Biggin pays but it's probably 5 digits or low 6 digits per year. Any comments from those close to the game?

[Brooklands]

Currently, most (all?) airports that have full ATC already have a conventional IAP
I think that there are currently three airports in the UK which have full ATC but don't have a published IAP. I know there's definately one as I'm based there.

Brooklands

[S-Works]

Redhill has ATC and no IAP.

[Jumbo Driver]

One was a 737 pilot and the other was an A340 pilot.

They appear to be flying procedural NDB approaches (outside the UK) so the "TOD" would be the FAF - the start of the final inbound leg on which you are tracking the NDB inbound.

No, IO540, TOD (Top Of Descent) is the point at which you leave cruise level to begin descent to destination. It is neither the FAF nor the point at which you descend from platform height within a procedure. Terminology is important.

With regard to a non-precision approach, such as a NDB approach, the approach aid must be both initially identified and monitored all the time during which it is being relied upon for tracking guidance. Whether this is done manually (i.e. aurally) or automatically is immaterial. However, it must be monitored during the approach, for obvious safety reasons.

In my opinion, your 737 and A340 pilots either misunderstood the question - or are misled in their belief.


JD
:)

[Contacttower]

Redhill has ATC and no IAP.

Redhill I imagine would fall foul of the requirement to have an instrument runway....although perhaps Wycombe Air Park's runway would meet the requirements?

[matspart3]

It's not just an 'ATC service'...the ANO (too tired to look up the reference) requires an 'Approach Control' service to be provided.

[IO540]

In the Class G context, nobody can "control" traffic.

Therefore, is there a legal obstacle to a FISO providing an "information" service for the purposes of scheduling traffic to the IAF?

In the USA, they deal with this by the IAF being in Class E, which is CAS for IFR and positive ATC control can thus be exercised.

But in the UK, ATC could not control the traffic anyway, even if the billing issues were resolved. All they could provide is a standard radar or procedural service, which any pilot could disobey legally (if he advises ATC of the fact).

And if the UK IAF was in CAS, say some existing Class D, we would then be back to the old problem of ATC sometimes refusing entry into CAS, thus making the airfield sometimes inaccessible to IFR traffic.

[beerdrinker]

IO,

It is not a "European" problem but a UK CAA one. There are GPS approaches at a number of European airports (including Hungary). The CAA are being there normal pathetic, money grabbing selves. See below the Email string I had with a German pal about GPS approaches:

Do the airports concerned (STRAUBING & EGGENFELDEN) have full Air Traffic Control, and are they “licensed”. Can one use the procedure to land at the airports when there is no ATC? I quote the UK CAA proposed approval: “The CAA has approved the use in the UK of RNAV (GNSS) Approach procedures. RNAV (GNSS) 2-Dimensional Non-Precision Approach (NPA) procedures and 3-Dimensional Barometric VNAV (APV Baro VNAV) approach procedures will be authorised only to suitable instrument runways, at appropriately equipped licensed aerodromes with Air Traffic Control (ATC) services.”

Best wishes,

T
"Hi T,



we don't have these term "licensed" for an airfield. For the period of an approach there is an airspace "F" activated, which means traffic advisories for VFR and IFR. The "Tower" has the Information function as for VFR and gives no clearances. The airfield requirements are manned Info Freq and ATIS, besides the approved approach procedure, of course.

best regards

F

So taking the example of Blackbushe.(If it was in Germany). It does not have ATC – it has an Airfield Flight Information Service (AFIS). He is not a controller. He issues advisories – QNH, QFE and traffic info. So reading your email, if Blackbushe was in Germany and the AFIS was working and there was an approved approach procedure one could fly an approved GPS approach?


T


"exactly, Blackbushe is directly comparable to Straubing oder Eggenfelden"

F

[bookworm]

beerdrinker

The situation in Germany is not quite as clear cut as you suggest. Munich Approach is responsible for the separaion of IFR departures and arrivals from/to Eggenfelden and Straubing. Just because the approach control unit is not sitting at the airfield doesn't mean that there's no ATC. There is however no aerodrome control, just an information service.

That doesn't mean we couldn't learn from the German model in the UK, but if you want to have the equivalent of the situation in Bayern, you need to get LTCC to control approaches into Blackbushe. I doubt that would be arranged as cost effectively as it is with/by the DFS.

[Brooklands]

The third UK airport with full ATC but no published IAP is Lands End. Bose-X and Contacttower have identified the other two.

Brooklands
Based at Wycombe

[Spitoon]

There seems to be some misunderstanding going on here about ATC and instrument approaches.

The two things fundamentally are different. If you want to get down from above cloud (or whatever) onto a visual approach to a runway, you need an instrument approach procedure. If you want to be separated from all the other aircraft, you need an ATC service. If you want both, you need to go to an airport that has both (and some appropriate airspace).

In the UK, for some reason or other, the two have generally been inextricably linked for many years because of some legislation. This is not always the case elsewhere.

Unfortunately, the CAA - and a good few pilots - seem unable to unlink the two things. Personally, speaking as a controller and sometime IFR GA pilot, I have no problem with the concept of doing instrument approaches to unmanned airports - all I really want is a radio frequency to talk to other traffic and some confidence that we're all going to be sensible.

[Contentious mode on] Frankly, I'd prefer that to doing it at some airfield with a FISO who likes to think he should have been a controller and being surrounded by pilots who don't know what services they should be getting and what their responsibilities are. [OK, back to normal now I've got that off my chest]

Of course, for commercial, passenger-carrying operations my own view is that the aircraft and its approach should be protected by class D or better airspace and the aircraft should be in receipt of an ATC service (both aerodrome and approach control). If I've paid for a ticket with an airline, I think I have a right to accept the same level of protection and service whether I'm flying in or out of Heathrow or some island strip. And that's something else that the CAA doesn't seem to understand!

[beerdrinker]

BW,

Not LATCC. Farnborough are next door. In fact nowadays, if you are on an IFR plan into Blackbushe, LATCC hand you over to Farnborough who "control" you till you are VFR.

[Fright Level]

Not LATCC. Farnborough are next door. In fact nowadays, if you are on an IFR plan into Blackbushe, LATCC hand you over to Farnborough who "control" you till you are VFR.

Same in and out of Fairoaks who also "share" the standard IFR routes in/out, however London tend to hand you over to Farnborough in the descent out of the TMA so although Farnborough are controlling you, you do become under a radar information service outside of controlled airspace in the final 20-30 miles into Blackbushe/Fairoaks.

Farnborough will only descend you to 1700 feet which is the limit of their radar min safe altitude, any lower you are responsible for your own terrain separation.

[IO540]

Farnborough could provide an approach service to GPS approaches at the various SE airfields, all the way down to Shoreham, and Manston could do Lydd, but under the UK system somebody will have to pay for the service, and it is inconceivable it would be cost effective.

Manston Radar is notamed unavailable most of the time nowadays so perhaps they are running out of funds for the more expensive ATC staff who are authorised to see a radar screen?

It is perfectly easy, and not illegal in a G-reg, to get the contour map out and develop your own GPS approach to any of these airfields. With a generous MDH, say 600ft, it is very easy to do. Just not "official" and because it cannot be inserted into one's GPS database, one needs to be pretty careful how one uses the waypoints.

[chevvron]

One problem with an iap to Blackbushe is the presence of the Bagshot mast. I did try to work out a rough NDB procedure to runway 25 based on ICAO Doc 8168 a few years ago, but there may be other obstructions on their type 'A' chart which I didn't take into account. Bagshot mast would also affect iaps to runway 07 as it's in the Misssed Approach area.

[IO540]

Can't "almost" any obstruction be handled by having a high enough MDH, perhaps with an offset final approach track? There are a few airports like that, on which every approach is formally a circling approach.

[chevvron]

Once you've got an MDH/OCH, this isn't the end though; a minimum visibilty/RVR must be worked out depending on lighting and visual aids (runway markings) available.

[Fright Level]

One problem with an iap to Blackbushe is the presence of the Bagshot mast

The second (and bigger problem) is the presence of the EGLL control zone. There is no way (except Fairoaks/Denham ATZ's) that they will let you into the zone without controlling you themselves.

[fred737]

Quoted in this weeks Flying News. How they do it in the States:

FAA 'Flight Plan' for 2009 Focuses on Safety
and Capacity
This year's forward-looking report from the FAA puts much of its emphasis on advancing safety and improving airspace capacity. The agency wrote that it expects to commission 500 GPS WAAS approaches in 2009, providing lower minimums and safer access to more airports.

Wouldn't we love to have another 500 GPS approaches in Europe?

[Islander2]

The agency wrote that it expects to commission 500 GPS WAAS approaches in 2009And that's on top of the 7,500+ GPS WAAS-capable approach procedures that the FAA will already have operational by the end of this year. No, that's not a misprint ... >7,500!

By the end of September 2008, this number included 1,333 semi-precision WAAS LPV procedures with ILS-like minima, exceeding for the first time the number of ILS procedures available throughout the USA.

Nice to see the UK maintaining its historical position at the leading edge of aviation.:*

[IO540]

This is why I don't understand the rationale behind putting in an approach approved GPS today.

GPS approaches will remain virtually irrelevant in the UK (and most of Europe) for as long as the CAA requires full ATC, and then (assuming the ATC is exempted) for as long as the airfield gets billed by the nearby radar unit (NATS) for the radar service.

Neither of the above practices is applicable in the USA, which is why they are so far ahead.

[mm_flynn]

With a sensible regulatory structure putting GPS Overlay approaches in place would make sense

1 - Over time you could phase out the DMEs (maybe very interesting if OFCOM has their way)

2 - You create a framework to introduce LPV approaches in the near future - saving the megabucks for an ILS in places like Oxford and Lydd that have just sprung for all of the ground based radio kit (you would still need to some extent the ALS).

3 - Basically all airports with an IAP could have a high quality approach to each runway and as soon as EGNOS/WAAS becomes operational they could have a virtual ILS to each runway.

It obviously would be much better if the CAA allowed approaches without based ATC (as in the US and many other countries) this would really open up the utility of GA in the UK.

[IO540]

It is IMHO inconceivable that EGNOS/Galileo based approaches will be permitted without the EU getting money out of it. Anybody seen the unbelievable revenuw projections for Galileo? They are not going to suddenly going to make this a free GPS network - not for the extra precision signals.

They won't be able to get money out of pilots (difficult since nobody is going to make modified GPS receivers which can receive encrypted signals for which the pilot would purchase the key, Jeppesen-style) but they sure as hell will levy a charge on airports publishing GPS approaches with vertical guidance.

They could levy pilots, by charging a tax on flying the approach, of course. As many countries do already, collected conveniently via Eurocontrol alongside the route charges.

So putting the old ILS on Ebay may take longer than we expect :)

Also, the bulk of the existing commercial fleet cannot fly GPS approaches and won't be able to for many years. Even PRNAV compliance is many years away if one is looking at anywhere the near the whole of the jet transport (pax and cargo) fleets flying into Europe.

It will happen but many years away.

[chevvron]

There IS an airfield in England with FIS and iaps; any guesses?

[IO540]

Scotland somewhere? Islay?? But only for CAA approved operators, IIRC.

In fact there are loads of airfields without ATC and with IAPs, but the IAPs are confidential and only CAA approved firms can fly them.

[justinmg]

I dont understand how you can safely have an IAP with no ATC. If you have no one providing instructions and landing clearances, then you could have someone not visual on the IAP at 1000ft on final, and someone turning in from the circuit in front of them (or am I missing a vital piece of the puzzle?)

[chevvron]

Try a bit south of Scotland (that's why I specifically said England!) It's a haven for Kingairs.

[IO540]

I dont understand how you can safely have an IAP with no ATC. If you have no one providing instructions and landing clearances, then you could have someone not visual on the IAP at 1000ft on final, and someone turning in from the circuit in front of them (or am I missing a vital piece of the puzzle?)How do they do it (very safely) in the USA?

There's your answer.

They use a nearby IFR (radar) controller to control the traffic to the IAF. After that, the approach is all yours.

As for mixing with circuit traffic, it's the same problem as in the UK. If you get visual early, you look out for them. If you get visual late, there should not be any circuit traffic because they would be in instrument conditions, which is illegal without a clearance in Class E (which is how it's dealt with in the USA).

Chevvron - you win. Go on, do tell me :)

[Flyboynick]

Is it Barrow-Walney Island?. ILS procedure with only an AFIS on the ground. I understand instrument arrivals are handled by Warton Approach.

Nick

[chevvron]

Isn't that just what IO540 just said? So it IS possible and must have been approved by CAA.
Yes it is Walney Island.

[IO540]

Has anybody asked the CAA how they allow this (EGNL) while maintaining mandatory ATC (as they do!) for general use?

Does the airfield get billed by Warton Approach (NATS?) and if so, roughly how much?

These are the two issues: mandatory ATC, and the billing from the approach service.

[Sir George Cayley]

"Waton good morning Vickers 01"

"Vickers 01, Warton, identified 10 miles south of Warton say your flight level"

Now lets look at the evidence, as a famous Bostonian once said. A cupla q's

Who owns Warton?

Who owns the shipyard at Barrow?

Internal budget transfer? Not really german sorry germain to this thread?

Discuss


Sir George Cayley

[Spitoon]

Has anybody asked the CAA how they allow this (EGNL) while maintaining mandatory ATC (as they do!) for general use?
IO540, your premise is nor strictly correct.

You could ask the CAA and I suspect they'd refer you to ANO Article 103 which says:

In the case of an aerodrome (other than a Government aerodrome) in respect of which there is equipment for providing aid for holding, aid for let-down or aid for an approach to landing 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.

At Walney there is an ILS, so the person in charge has to cause an approach service to be provided. This service is provided by Warton, presumably by an arrangement in which the boss at Walney causes Warton to do it (don't you just love lawyer-speak?).

If so, it's all perfectly legal and doesn't require and aerodrome control service at the aerodrome - in fact, it doesn't even require a FIS to be provided.

[IO540]

Wot you are saying, Spitoon, is that ATC is required but doesn't have to be anywhere near the runway :)

Which I agree with. Nobody actually needs to see the plane landing - the pilot is perfectly capable of looking after himself at that point.

So.... what is America doing differently? (a question both rhetorical and genuine)

One thing is that the USA has a neat airspace trick: Class E down to a low level, which is OCAS for VFR so in good weather everybody can do what they like, but in the muck a pilot flying the IAP is unlikely to suddenly encounter conflicting IMC traffic (pretending to be VFR) because such traffic would be IFR and since Class E is CAS for IFR the conflicting traffic would need a clearance which they know they haven't got... It seems a good system but a major airspace revision in the UK never mind Europe is almost totally off the cards for political reasons. And it wouldn't happen in the UK anyway because somebody would have to provide a service to all IFR traffic flying in the now-copious Class E, and who is going to pay for this?? It works in France and in the USA, for example, because they don't have the "user pays" billing system. The UK just loves its widespread Class G because it absolves the UK from having to provide any kind of mandatory service in it.

[Roffa]

IO,

For future reference, here's where NATS provides area services...

En Route Services - NATS (http://www.nats.co.uk/text/77/en_route_services.html)

And here's where they provide airport services...

Airport Services - NATS (http://www.nats.co.uk/text/78/airport_services.html)

[bookworm]

In the case of an aerodrome (other than a Government aerodrome) in respect of which there is equipment for providing aid for holding, aid for let-down or aid for an approach to landing by radio or radar,...

Hmm. Now there's an interesting thought provoked by Spitoon. If a GPS approach is designed and promulgated, does that necessarily fall under the the provisions of this article? The "equipment" is not "in respect of the aerodrome", is it?

[Spitoon]

I had some involvement with work the CAA did a few years ago on approaches without ATC. The law has been on the books for many years and there were no clear records about why it was introduced. The general concensus was that the law was written at a time when airports ran their own approach aids and no-one ever imagined that an airport could have approach control without aerodrome control - but was a round-about way to say you have to have ATC to do an IAP. It was thought that the law was introduced following an incident or accident where things didn't go well when someone did an approach without ATC. Strangely, the work that I saw was prompted by an AIRPROX where two aircraft were trying to follow an IAP and to 'separate' themselves...and failed.

On the law, things are different now and the wording doesn't fit today's world so well. But it is still in force and happens to fit the situation at Barrow.

There was also discussion about GPS approaches and a revision to the law was drafted that was couched in more general terms. I don't know whether that draft is still under consideration. As it stands, GPS approaches simply don't fall within the scope of this bit of the legislation as far as I can see.

[beerdrinker]

This weeks Flying Newsletter:

"WAAS–Based Approaches Now Outnumber ILS's
To be correct, we should really be calling them Localizer Performance with Vertical guidance (or LPV) approaches; but most pilots simply refer to them as "WAAS" approaches. That's because they are based on the Wide Area Augmentation System for GPS enhancement. Now that the FAA has commissioned the 1,333rd such approach, they officially outnumber the stalwart ILS—technology so old that its initials stand for 'Instrument Landing System,' as if there ought never to be any other kind. LPV approaches are desirable because, being satellite based, they do not require the clear areas and extensive ground radio equipment of an ILS, consequently costing a fraction of the investment involved in installing ILS capability—usually millions of dollars. The LPV approaches do still have their limitations (see today's Left Seat), but with the FAA planning to add 500 new ones per year, the agency clearly views the technology as the wave of the future."


It makes you realise how pathetic the CAA are.

[IO540]

It's the whole of Europe, beerdrinker.

To do a "GPS glideslope" you need WAAS (USA) or EGNOS (Europe) and while EGNOS is operational, it is not operational "officially". The signal contains a "valid" flag and an IFR GPS is not permitted to use the signal if this flag is not set. A handheld can, which is why say a Garmin 496 can use Egnos right now.

Somebody in Europe will have to get their head together and authorise EGNOS for real use.

How the UK CAA is going to solve the ATC and approach service billing issues, I haven't got a clue.

[Talkdownman]

Yes, no apology, but resurrecting a most ancient thread. I have taken my eye off the ball concerning the situation regarding RNAV IAPs to uncontrolled fields. I would hope that some progress has been made over the last eight years since the last discussion. Could there just happen to be a precedent, yet, where there is an approved GPS/GNSS/RNAV (call it what you will..) approach to an uncontrolled aerodrome in the UK with no more than AGCS?

MTIA...

[dont overfil]

I believe there is a backlog of applications for approval from licenced airfields. Unlicenced will probably have to play second fiddle.
By the way the cost is substantial even with the grant.
I don't know if any fields without the usual infrastructure have been approved but we were advised how to apply. It was suggested we had a good chance.

[foxmoth]

If the authorities do not take the lead here what will happen (I suspect actually already has happened) is that people will sort out their own approaches with their own minima, many pilots will be very capable of doing this, but I suspect there will be others that will have a self designed approach that should never be allowed, far better to have these properly assessed and approved.:ok:

[Pace]

Foxmoth

I agree with what you say but will just add that some pilots will cock up on approved approaches too

Pace

[Pace]

Foxmoth

I agree with what you say but will just add that some pilots will cock up on approved approaches too
One big safeguard on the majority of approved approaches is the beady eye of radar
Take that away and you have pilot interpreted approved approaches which become less safe
Does that mean that ALL home made pilot interpretated approaches are less Safe ? Because they don't have the stamp of approval ?
Home made unapproved approaches can be safe but if something goes wrong they are unapproved and not authorised approaches and the finger of the authorities and insurance will rightfully or wrongfully point at the pilot

Pace

[Talkdownman]

even with the grant
Grant? What grant?
Is CAA-approved GNSS to unlicensed with AGCS legal yet?

[piperboy84]

I made up a half assed GPS approach to my grass strip with fixes and altitudes as user waypoints and fly it all the time VFR. But when the rubber hits the road and it's time to use it to get down thru cloud I always chicken out and go shoot the ILS from in over the North Sea till visual at nearby Leuchars Air Base, then fly back up the coast to where it meets the valley that is a sea level run right to my strip.

Homemaders sound good in theory but I just don't trust myself without the good old CDI/GS crosshairs of a precision approach, even if Leuchars is not published.

[Pace]

Homemade approaches are a taboo subject frowned on but used in surprising quarters even by commercial pilots who should know better.

How many out of the way airfields do you hear that the local guys come down to xyz often with overlaid GPS NDB DME or confirmation point fixes off VORs etc and appear to get in in pretty bad weather?

Yet hardly any admit to it or want to be associated with such cowboy antics
As stated they are not all unsafe because they don't have the stamp of approval and many use those methods for years but if anything goes wrong beware as you will have a lot to answer for if your around to answer.

They are procedures that are universally frowned on but quietly carried out

Pace

[Talkdownman]

'Home-made', 'back-of-envelope' RNAV approaches aside, I am simply trying to find out if, in the UK, there are any CAA-approved RNAV approaches to unlicensed aerodromes, and/or CAA-approved RNAV approaches to aerodromes without ATS (ie. ATC or AFIS). I am trying to find out if it might be possible to have a Regulator-approved GNSS RNAV approach to an unlicensed aerodrome with AGCS. (I do know that RNAV safety case and approval charges in GBP will be similar to Global Express cruising altitude numbers...)

[dont overfil]

As I said I don't know if any have been approved yet but there was considerable help available through some members of PPLIR and the group fighting red tape. There is an application process in place and there are at least two companies I know of offering a design service. Cyrrus and Gcap.


A 60% grant is available from EASA towards the cost. There are several Scottish airports which already have ground based navaid approaches waiting for approval for GNSS approaches but things are moving very slowly.

[Pace]

Here I blame the authorities in aviation for the very slow turning wheels and huge costs of getting such approaches approved
This has forced many pilots into the home made unapproved risky approaches
The authorities could approve approaches Quicker and at far less cost albeit with higher minima !
But maybe GA and small airfields don't really figure highly in importance the rate these airfields are being closed and turned into housing estates
The bigger airports don't want us as the pricing shows hence something will have to be done to stop light GA turning into a sunny afternoon hobby sport

Pace

[Sir George Cayley]

Looking at the Campaign's Official Record Series ORS5 No 278 costs of approval per IFP appear quite reasonable e.g. APV BaroVNAV/SBAS £640.

So where are the heavy costs to be found?

SGC

[dont overfil]

While I cannot give you a detailed breakdown at the moment, what needs to be paid for is:
A survey for each approach.
The design.
Flight survey.
CAA approval.
Cost for the release of the "chip" for publication.
I am told for our local field this comes to around £60000.


Talkdownman
The OP of this thread may be able to give you the information you ask for.

[Talkdownman]

A 60% grant is available from EASA towards the cost. There are several Scottish airports which already have ground based navaid approaches waiting for approval for GNSS approaches
TVM DO. I do wonder if that is for locations where 'community flights' represent essential communications, eg. H & I, rather than such locations such as GA or 'contractors' aerodromes'.

I have had a verbal quotation not too dissimilar from your figures. The company concerned is optimistic that it can be achieved.

Just re-visited the original post. I would hope that after 8 years in aviation development a much more pragmatic approach (forgive the pun...) would apply. For such huge five-figure expense I would at least expect approval for a GNSS RNAV approach to an unlicensed instrument runway with AGCS. We'll see...

Thanks Chaps.

[BEagle]

...This has forced many pilots into the home made unapproved risky approaches...

A couple of fairly recent fatal accidents in poor weather at aerodromes without published or discreet approach procedures may well prove the veracity of that statement.

[Pace]

Beagle

If one of the accidents in a Malibu is what you are referring too? Then its doesn't appear that there was any sort of planned approach approved or not but purely scud running on a wing and a prayer

Pace