CAA sets up GPS approach trials for GA [Archive]

rustle

30th Mar 2006, 12:00

This was all in the latest GASIL 1 of 2006 issued March

GPS Non Precision Approach Trial

As the first step in allowing global navigation satellite systems to be used for non-precision instrument approaches in the UK, the CAA has set up a trial at 6 aerodromes around the country, Inverness, Durham Tees Valley, Blackpool, Gloucester, Shoreham and Exeter.

The CAA’s Directorate of Airspace Policy has designed non-precision approach procedures for a runway at each of these aerodromes, and suitably qualified pilots with approved equipment are encouraged to join the trial, fly the approach and submit their reports.

The trial will commence on 11th May 2006.

While the trials will of necessity be conducted in VMC, the aircraft involved must be British registered, and equipped with approved satellite navigation equipment complying with E/TSO C129a Class A1, as a minimum. Pilots with valid UK instrument ratings or IMC rating privileges may take part, by registering with the independent web site www.gpstrials.leeds.ac.uk which is being set up by Leeds University and Imperial College. After registration, the same web site will provide the necessary information, guidance and reporting forms for the trial.

Full information will be contained in an AIC to be issued shortly and to which interested pilots should refer.

We would remind pilots that when flying these trial approaches, Rule 7 of the Rules of the Air requires that not only must they inform the appropriate ATC unit of their intention, but that a competent observer must be carried on board in such a position in the aircraft that he has an adequate field of vision and can readily communicate with the pilot flying the aircraft. Such an observer of course may be the ideal person to actually fill in the few parts of the report form which have to be completed during flight. The trial is due to end on 25 October 2006 and collated results should be available early in 2007.

IO540

30th Mar 2006, 14:08

Sounds like any BRNAV GPS will do, even if (as is normal in a G-reg) it is placarded "en route use only, not for approaches".

Anyone disagree?

What if it is just a GNS430/530 that has been screwed into the panel and is not an approved installation, but the GPS itself is TSO'd.

I still think it's daft to exclude N-reg pilots. They are just as able to spell, and to follow their GPS in VMC. If this is a scheme genuinely intended to collect data, this restriction makes no sense.

The other point is that anybody can fly one of the existing approaches in those airports, using a GPS alongside the traditional navaids ;) In real IMC, too. And even if they have the wrong stickers on the side of their plane.

NorthSouth

30th Mar 2006, 14:15

I notice that AIC Yellow 205, which is referenced in the announcement, isn't available on the AIS website despite the claim to the contrary, nor is it listed in the 'latest batch of AICs' due for issue on 30th March. So you can't actually read about the equipment requirements anywayAnd the trial website which you need to look at for details of equipment specs is password-protected with no clues as to how to register.
NS

bookworm

30th Mar 2006, 14:32

AIS Sup 9/2006 (http://www.ais.org.uk/aes/pubs/aip/pdf/sup/506009.PDF) has the details.
So let me see...
On Feb 17 1994, the FAA started to permit operators to fly GPS overlay non-precision approaches with the (RAIM-assisted) GPS acting as the sole operating navaid. Manufacturers encoded existing approaches into their databases, and no surveying or drafting was required. Shortly afterwards, in Phase III of that program, virtually all US non-precision approaches had "or GPS" appended to their title, allowing them to be flown as overlay apoproaches.
At the same time, the FAA started to create standalone GPS approaches in the now-familiar T-shape, and eventually substituted these for the overlays. These now have more than 10 years of operational IFR use in the state with by far the largest number of aircraft movements in the world.
So I have 3 questions:
1) Has the CAA totted up the amount of money that operators have spent maintaining traditional avionics in the intervening 12 years, money that could have improved safety in countless other ways?
2) Could this delay, followed by a sudden movement to release GPS approaches, have something to do with the impending transfer of approach design to the private sector, and the fees that the CAA will derive from approving new GPS approaches which would be lost if overlays had been approved?
3) What the hell are we testing?

IO540

30th Mar 2006, 16:23

I am confused.

Why would the CAA have not made money out of overlay approaches?

By "overlay approaches" do you mean those already in the GPS database - most UK's NP IAPs are already in there.

I can see that if those somehow got approved, then CAA would not have made money out of them. But who would have approved them? EASA? Anybody can fly these already, because nobody can tell which instrument you are looking at during the approach.

In connection with your 3) question, I am baffled too because if these approaches are not inthe database (i.e. one needs to program the waypoints manually) the GPS won't switch into the more sensitive terminal mode when past the IAF.

bookworm

30th Mar 2006, 16:35

By "overlay approaches" do you mean those already in the GPS database - most UK's NP IAPs are already in there.
...
Anybody can fly these already, because nobody can tell which instrument youa re looking at during the approach.

They can tell if you don't have an ADF, VOR or DME installed, can't they?

Flying an "NDB approach" using an ADF and a GPS side by side is one thing. Flying an "NDB or GPS approach" after you've thrown the 20 lb shoebox of an ADF in the skip years ago is quite another.

mark147

30th Mar 2006, 16:56

In connection with your 3) question, I am baffled too because if these approaches are not inthe database (i.e. one needs to program the waypoints manually) the GPS won't switch into the more sensitive terminal mode when past the IAF.
I think that's clear from the AIP SUP: the procedures will be in your database if you have an up to date database. Having an up to date database is a condition of using the approach (see para 3.3).

Mark

A and C

30th Mar 2006, 17:50

To make a GPS approach the Approach MUST be in the data base, YOU CAN'T ENTER THE WAYPOINTS YOUR SELF

The reason for this is the GPS has two approach modes that have to be working to make the approach these will not become active if the approach is not in the database.

When the approach in the database is selected and the aircraft reaches 30NM from the airfield the Approach mode arms and the CDI scale factor changes from +/- 5NM to +/- 1NM.
When the aircraft is within 2NM of the FAF inbound the GPS auto selects "approach active" mode and the CDI scale factor changes (slowly) to +/- 0.3NM.

IO540

30th Mar 2006, 18:30

A&C

That's exactly what I was getting at; the sensitivity increase won't happen with user-entered approaches. I have a 13-cycle subscription and a current DB & will have a look for this RNAV IAP next time I fly. It certainly didn't feature in this month's batch of paper updates for the Jeppesen IFR guide for the UK.

Not that I can actually fly it anyway, being N-reg.

Bookworm

I didn't say one would be flying the RNAV IAP without carrying the traditional equipment too. Most people flying what one might call serious IFR will carry all the kit, not least because they have to for airways flight.

What did you mean about "overlay" approaches not raising funds for the CAA?

A and C

31st Mar 2006, 06:08

Any BRNAV GPS unit will fly a GPS aproach if the data is in the database (if your GPS has a ground mode try the APP at Lille) the problem comes with the instalation as that has to meet the TSO as well as the box.

A lot of avionic shops will have installed the units without meeting the full TSO, this is because they have to compeat on price and the owners will always go with the cheapest option (most of the time the owners don't have a clue about what they are buying and how it works). the CAA must take part of the blame for these instalations because of the anti-GPS attitude that they have taken over the years.
After all the avionic shops have been installing GPS units that the CAA has mandated are only advisory and not for IFR terminal and approach navigation so why should tha avionic shops blunt there compeditive edge by installing to the full TSO if the CAA won't approve the kit to do what it was built to do?

As the owner of an aircraft on a "G" plate that has had the full TSO approach GPS instalation since 1996 and not had a hint of a problem with the kit GPS aqproaches could not come soon enough for me, the only thing that I can't get my head around is why the CAA can't use data from the FAA after all GPS approaches have been a reality since 1994.

The real problem is that the luddites at aviation house have dug them selfs such a political hole over the years with there anti-GPS attitude that these "trials" are the only way to save face. Its high time that they admitted that they have been wrong on this issue and got on with intoducing "lay over" GPS approaches now and pure GPS approaches ASAP.

Now doubt they will be using the safety issue to suport the trails policy but for years pilots in the UK have had to make ADF approaches when a GPS approach would have been far safer, this is the real price of the CAA's attitude to GPS and a little searching if the accident/incident data over the last few years might be revealing, but I will leave others to look at the NP approach safety records.

IO540

31st Mar 2006, 06:27

A&C

What is needed to meet "TSO" on a G-reg? Does it mean anything?

Possibly you mean BRNAV. That's what's relevant to the European BRNAV requirement (FL095+). That is a real requirement in Europe - mandatory in fact.

I must confess I don't understand this myself. I know that (in the FAA context; it has never been relevant otherwise) an "IFR approved GPS" has to come with the specified annunciators e.g. a separate CDI or HSI indicator, plus a TERM lamp which lights up when in the more sensitive Terminal mode, and other stuff like that. Plus a flight test, and a GPS supplement in the POH authorising IFR usage, specifically authorising approaches or just en-route.

But on a G-reg the thing would not have normally got a CAA CofA (done by a CAA inspector) unless placarded "VFR only" (along with EXIT stickers on the doors). In which case compliance with any American IFR requirements is irrelevant. I know of one exception, a new TB20 built for the USA which slipped through and which was placarded "en route only" but the POH did not come with a GPS supplement. Later, it was discovered, the DGAC-approved GPS supplement had always existed but it authorises IFR use only for en-route and even then only if the database is current and the pilot manually checks all waypoint coordinates.

The CAA flyer on these approaches (the link from bookworm) suggests that a mere TSO129 GPS screwed into the panel should be sufficient - without the CDI/HSI indicator.

So the whole thing is a mess.

It's particularly stupid of the CAA to limit these trials to G-reg because so few G-reg planes with have a BRNAV approved installation with a current database with a GPS supplement authorising IFR use with a pilot who knows how to use it with the database containing these particular approaches. Whereas with a current N-reg PPL/IR pilot they might have got some feedback...

2Donkeys

31st Mar 2006, 06:58

bookworm

31st Mar 2006, 13:49

I didn't say one would be flying the RNAV IAP without carrying the traditional equipment too. Most people flying what one might call serious IFR will carry all the kit, not least because they have to for airways flight.

No exactly. But the FAA did permit precisely that -- GPS approaches without the "traditional equipment" being carried. The Cirrus owner, without ADF, can't fly an overlay NDB approach in the UK, but could in the US.

The airways requirement is similarly anachronistic.

What did you mean about "overlay" approaches not raising funds for the CAA?

If the CAA were to put a blanket approval on overlay approaches right now (as the FAA did 12 years ago), they'd lose all the revenue they'll get from design of standalone GPS approaches in coming years.

rustle

31st Mar 2006, 14:19

The real problem is that the luddites at aviation house have dug them selfs such a political hole over the years with there anti-GPS attitude that these "trials" are the only way to save face.

The entire issue, captured in a nutshell.

They're damned if they do and damned if they don't then, aren't they?

For ages people complained (here and elsewhere) that the CAA were anti-GPS etc., the CAA decide to do some GPS trials of their own (last time I checked the CAA weren't part of the FAA) and that's wrong, too.

As for complaining about restricting the trials to G-reg and/or CAA pilots - WTF?! :rolleyes: Any national authority would do the same, FFS!

bookworm

31st Mar 2006, 15:41

For ages people complained (here and elsewhere) that the CAA were anti-GPS etc., the CAA decide to do some GPS trials of their own (last time I checked the CAA weren't part of the FAA) and that's wrong, too.

Golly-gee you're right old chap! We need trials. Maybe physics drives on the left side of the road in the UK? Maybe those perfidious yanks have been selling us TSO-129A kit that doesn't work for approaches. Maybe the database uses American spellings. I just wouldn't feel safe flying the same sort of approach that have been flown operationally millions of times before in the US over the last decade, unless someone had done it in an aeroplane with "G" painted on the side.

rustle

31st Mar 2006, 15:52

Are you going to assist in the trials?

I am. Durham Tees Valley I use and will be using a lot more during the period of the trials...

Whatever the motivation for the trials I'd rather get on with it and have GPS approaches usable in the UK than not. If it takes until 2007 that's still sooner than never :)

Wonder if the Jepp subs for the Garmin will go up once there are approved GPS approaches in the UK :rolleyes:

JW411

31st Mar 2006, 16:03

I think my friends on the HA, LY, EC and OO registers should also be allowed to join in the trials.

At least their aircraft are registered in EU countries and not registered on the other side of the Pond.

IO540

31st Mar 2006, 16:29

The CAA has a helluva long ladder to climb down on this one, and they will need time, and lots and lots of trials ;)

Even so, given that anyone flying airways/IFR in Europe will still have to carry ALL the old kit anyway for the foreseeable future, the relevance of these approaches (implemented as they are going to be only where there is full ATC and therefore existing P/NP approaches) is a lot less than in the USA, where one doesn't have to carry ADF/DME.

If you carry all the kit anyway, you can fly the existing depictions of the old approaches that already are in the Jepp database.

Especially as the RNAV MDH happens to be not significantly lower than the old stuff.

Incidentally, there have been, AIUI, trial GPS approaches at Gatwick for some time. Have these been limited to G also?

Can anyone think of a genuine reason why these trials should be limited to G?

I've just read something suggesting that the party that is having the last laugh is not the one most here would expect :O The CAA has dropped a major clanger.

Feather #3

2nd Apr 2006, 22:36

Just to give you a "heads up" on the accuracy figures.

Some comments say the BRNAV certified units can make GPS approaches, and that may be true IF;
1. they're certified TSO-C129 or -C129A units [or higher], and
2. the approach is in the database!

BRNAV operates to RNP5; GPS approaches are down to RNP1 or lower. You confuse the two at your peril!!:uhoh:

G'day ;)

IO540

3rd Apr 2006, 06:39

That's a paper and certification distinction, Feather. Every GPS, so long as it's working at all, will give horizontal accuracy to a few metres, never mind RNP1 (1 mile). RNP1 is what a competent PPL with a map and a compass is supposed to be able to do :O

The more profound point here is that unless the approaches are in the GPS database, all one can do is fly them as a sequence of en-route user-entered waypoints, which proves nothing.

And they won't be in the Jepp database until the CAA opens up the approaches to all aircraft, not just G-reg that have registered with them :O

This makes one wonder what the CAA thinking behind all this was. These approaches cannot be flown with the GPS in the approach (terminal) mode.

Incidentally, which BRNAV-certified GPS units are not also certified in the USA for IFR (i.e. TSO-C129)?

Fuji Abound

3rd Apr 2006, 16:54

It does seem strange that you need to trial a system using aircraft built by the yanks (most, not all I know), using equipment designed by Americans and a satellite system owned by them.

Ah well, I suppose we do run our own ATC, and write on our own procedures. Maybe we need to test our ability in those departments. Oh, and also the pilots, as we can at least guarantee they will all have a European instrument rating of one sort or another.

I am waiting for the G1000 to have the procedure installed and give it a try.

IO540

3rd Apr 2006, 16:58

rustle

3rd Apr 2006, 20:05

All the present trial ensures is that anybody attempting it will be doing so with CDI sensitivity of 5 miles (full scale) rather than 1 mile or 0.3 mile which is what you get with a proper GPS approach.

What's the point of such a crippled trial?

And that's assuming people enter the waypoint coordinates correctly.

(I am not mentioning one obvious answer)

The assumption you are making is that one email from Jepp is correct.

It would be easy to believe the CAA are idiots but Jepp are accurate with their info 100% of the time, except for the fact Jepp have been wrong on so many occasions in the past, be it data, accounts or, dare I suggest it; their admin function... ;)

IO540

4th Apr 2006, 08:53

Well, the IAPs are not in the 16 March Jepp database, and that's a fact. I will see if they are in the 16 April...

bookworm

4th Apr 2006, 09:16

Well, the IAPs are not in the 16 March Jepp database, and that's a fact. I will see if they are in the 16 April...

The trial begins on 11 May 2006 (AIRAC cycle 5/2006). I would expect the approaches to be introduced in that db update.

DFC

4th Apr 2006, 18:34

The UK is under international obligation to ensure that all procedures published for use of visiting aircraft such as N reg meet all the international requirements or differences are published in the AIP.

To use N reg aircraft in a trial would require permission from the FAA.

Why?

Simply because it is a trial and as such there is no guarantee that the results will be as expected or in accordance with international standards.

US aircraft and their pilots are visiting from a country with plenty of GPS approaches so there is noting to be gained for them in taking part as they have had plenty of oportunity to practice in the aircraft's home country.

Regards,

DFC

PS IO540, the RNP for visual navigation depends on the frequency of fixes. Enroute, RNP5 is acceptable and helps ensure plenty of time is allocated to lookout.

Fuji Abound

4th Apr 2006, 23:21

"US aircraft and their pilots are visiting from a country with plenty of GPS approaches so there is noting to be gained for them in taking part as they have had plenty of oportunity to practice in the aircraft's home country."

I dont really suppose to many of N reg pilots who would be "trialing" these approaches in the UK have come with their aircraft and themselves from the States.

I do agree if they had, GPS approaches would be old hat - flown a few there myself.

However as I commented earlier it is difficult to see what is being tested other than the efficacy of the procedure, ATC and perhaps the pilot, unless of course you believe the equipment is going to obey different laws of physics this side of the pond.

JW411

5th Apr 2006, 20:53

I actually asked the CAA if they had taken the trouble to pass the temporary GNS let down information to Mr Jeppessen so that it might appear on my updates.

I was told that the coded info was sent out in Airac Cycle 6 which is published around April 13th. The AIP charts will also be Operational Charts.

I therefore expect Mr Jep to come up with the goodies on or about 16 May at the very latest.

Sir George Cayley

5th May 2006, 20:31

Just checked the website for the trial and...........

It appears to be working:) :) !!!!!!

One has to go through a right rigmorole (sp?) to register and Friday night is prolly not the best time to do this.

Sir George Cayley

S-Works

5th May 2006, 22:02

I will certainly be taking part. as the owner of a fully equipped G-Reg and hopefully a newly minted JAR IR the idea of GPS approaches is 7th heaven and not a moment to soon.

I think it is finally time to commend the CAA for doing this, yes maybe it is very late but better late than never!

JW411

6th May 2006, 17:27

After a tip-off from the Belgrano on Friday morning I successfully got myself registered yesterday. The paperwork involved is indeed comprehensive and I have not fully absorbed all the manifestations yet. However I might be able to stop some of you from wasting your time.

Unless you have a fully approved panel mounted GPS then save your breath.

Unless you have a regular update contract with such as Jeps then save your breath.

You are not allowed to manually load the various waypoints in such as users waypoints - they have to be in the database as a specific letdown.

Needless to say, there is more!

IO540

6th May 2006, 20:49

One should be grateful that the CAA is doing something positive on GPS for a change. There must be a lot of dead bodies on the floor at Gatwick.

The fact that the FAA has seen something of the order of 1 million GPS approaches flown over the past decade suggests that perhaps the CAA is looking to discover a new theory of relativity ...... but as I say we must be grateful :O

You need a GPS which is not just BRNAV but a fully TSO129 or TSO146 compliant installation and very few G-reg planes will have this - it's needed for airways only, which needs a UK/JAA IR and very few of those are flying around privately (most are N-reg). You also need a current database, which will cost you a few hundred dollars for a 13-cycle subscription; most IMC Rated pilots update their GPS at best as a one-off at the start of the flying season.

So the sample of pilots is going to be massively slanted.

It is currently uncertain when Jepp will include it in their database. Not in the coming update cycle, apparently, and until it's in there you cannot fly the approach.

tmmorris

7th May 2006, 18:00

So the sample of pilots is going to be massively slanted.

Yes, but on the plus side, it's going to be slanted in favour of very current IR pilots with excellent ac, who are hardly going to find this difficult/taxing/have major equipment errors. So the trials should be a foregone conclusion!

Tim

Saab Dastard

7th May 2006, 18:38

Of course, if very few aircraft and pilots can use them, and of those even fewer actually do - why then the CAA can turn around and say "well our trials show that nobody is using them, so there must be no demand, so let's just abandon the whole idea."

Cynical? Moi? ;)

IO540

7th May 2006, 19:18

It appears clear that the pilot population who can legally participate in this trial will be small.

You need all of:

1. G-reg plane,
2. legally PIC in it under VFR,
3. have a UK or JAA IR, or the UK IMC Rating,
4. have a TSO-129 GPS installed (basically, the full BRNAV GPS, with TSO-129 compliant indicators, annunciators, etc). A US-style IFR approved GPS would do but you won't one in a G-reg :O A GNSx30 which is just screwed into the panel won't do.
5. have a current GPS database, which means about US$200-US$500 payment depending on whether you choose to buy just a one-off update (which like all updates will be valid for 28 days max) or a multi-update option.
6. a safety pilot or a "competent observer"

I suppose there is a danger that they will get a lot of IMCR pilots flying planes which they think have an IFR GPS, when in fact they

a) have a GNSx30 screwed into the panel but not TSO compliant, and
b) have no idea how to use it in the approach mode

Now, b) above is very real, for practically nobody in the UK has ever had any need to know this highly equipment-specific procedure, and almost no UK instructor has any clue either. This should then highlight a need for special "approach GPS" pilot training, which won't particularly suprise me, given the general decrepit state of the UK PPL training scene.

If N-reg owners were permitted, it would be easy to predict that loads of pilots will be having a go, but I really can't even guess how many there are with access to a fully BRNAV/airways equipped G-reg wagon, and who fly on the IMC Rating. And everybody knows there are now very few European IRs flying on the private scene.

I have a newish plane with all the kit but can't do this because it's N-reg, but I have to confess that it is only recently, having been flying it IFR for 4 years, that I started pressing the PROC button on the KLN94 to see what it does....

What it does do is it pulls out the existing "overlay" approach from the database; these have been in there for years and are just abbreviated representations of the existing conventional-navaid IAP. Usually just the final approach track is shown, and usually this is all the guidance you need for an accurate GPS-assisted approach. You can similarly display a STAR or SID.

The details of the process is specific to the particular GPS.

drauk

7th May 2006, 20:43

You don't need a certificated GPS for the trial. It does have to be installed though - no handhelds. Top of Page 6 of the Pilot's Guide says:

For approaches flown in VMC, during the period of this Trial and for the purposes of
the Trial only, certification of the equipment for NPA operations is not required in the
AFM provided the equipment and aircraft installation meets the requirements as set
out in paragraph 6 of the Terms of Participation of the trial in this website.

https://www.gpstrials.leeds.ac.uk/briefing.php

On cessation of the Trial and for any future RNAV operations the appropriate
certification in the AFM or equivalent document will be required.

I might give the Shoreham one a go IO540, if you want to come along.

JW411

8th May 2006, 08:05

Paragraph 6 states:

For NPA operations, all GPS receivers and equipment must be installed in the aircraft in accordance with TSO C129a/ETSO-C129a Class A 1 or E/TSO C146A Class GAMMA and operational class 1,2 or 3 (including those not forming a component of an FMS navigation computer) and may be installed in single pilot aircraft.

Now the Note states:

For approaches flown in VMC, during the period of this Trial and for the purposes of the Trial only, certification of the equipment for NPA operations is not required in the AFM provided the equipment meets the following requirements:

a. The receiver must be configured to comply with the requirements of the TSO as detailed above.......

The way I read this is that the fact that the equipment is not listed as NPA compliant in the AFM is OK but the equipment and the installation still has to be TSO compliant.

IO540

8th May 2006, 08:51

That's my understanding too.

a) An IFR GPS alone doesn't count for anything here.

b) An IFR GPS with the TSO-129-specified annunciators (e.g. a TERM indicator, either on the GPS or somewhere on the instrument panel, in the pilot's primary field of view) and track error indicators (a CDI or HSI) is OK for the trial.

c) The above, with a POH supplement stating the GPS is OK for approaches will be required for flying them for real. This is the CAA's current position on this, and is at odds with say the French who are happy with their new GPS approaches to be flown with b) above. It would also be interesting to look in the Czech AIP to see the GPS requirements for the GPS RNAV approaches at LKPR....

A custom GPS supplement for a G is a "major mod" under EASA as is likely to be very expensive.