Norlander
Topic Author
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The Next Generation Of ILS?

Wed Oct 07, 2009 5:35 pm

I'm trying to assess the different new technologies that can be used instead of ILS, and was wondering if anyone on this forum had extensive knowledge of the issues, specifically how they relate to an airport like FAE, which has a non-precision approach, in part due to the approach to runway 13 not being straight - flying in through a fjord with 1500-2000 foot cliffs. The current plans (extending to a 6000 ft. runway) will alleviate some of the accessibility issues we have, but we're still dealing with flight cancellations due to bad weather (high winds during the winter and fog and low visibility during the summer).

I've spent time reading up on precision-GPS and particularly the Local Area Augmentation System, which currently appears to be qualified to Cat I ILS accuracy, but for this system to be of any real benefit we require Cat III ILS accuracy, so that aircraft can land in zero visibility. Is the LAAS system moving forward towards Cat III accuracy, or are other systems overtaking it?

What options would be best for an airport like FAE in the near-future (5 years), given the less then ideal physical parameters of the airport, as well as budgetary reasons (it's a fairly small airport). I'm under the impression that navigational aids are developing fast, at least from my time doing remote sensing work, and thus I'm confident that there will be a perfect system for us in the near future, but unclear on exactly what that system will be.
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rwessel
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RE: The Next Generation Of ILS?

Wed Oct 07, 2009 9:43 pm

Well, the three mainstream civilian options that exist now, or will exist in five years, and that can do at least Cat II, are traditional ILS, augmented GPS, and MLS.

MLS is largely dead in the US, but I think has some reasonable level of use in Europe. Whether it's practical for your users is a different story.

WAAS should eventually do CAT I (although I don't know what its status is in Europe), and LAAS should eventually get to CAT III, so LAAS appears to be the long term direction for the FAA. The ICAO and several European countries are working with the FAA on LAAS.

Frankly there isn't anything else coming in the precision approach world. Although I suspect Galileo will get integrated into LAAS at some point.

ILS is... ILS, and obviously does not deal well with curved approaches.

There might be a few other options to look at. TLS might work with limited traffic in some situations. And some military technologies are possibilities (PAR and JPALS). Although I don't know how well TLS and PAR work for curved approaches, and TLS is mostly Cat I anyway. And JPALS is very similar to LAAS. Frankly I don't think any of those are realistic options. And unless LAAS falls on its face, that's likely the only practical choice.
 
Woodreau
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RE: The Next Generation Of ILS?

Thu Oct 08, 2009 1:53 am

WAAS and LAAS are augmentations to the basic NavStar GPS signal and I believe are terms used to describe US efforts on that front.

As you probably know from your researching, WAAS is a satellite based augmentation that provides augmentation for a large area, whereas LAAS is a ground based augmentation that only covers the airport where it is installed.

Each country will need to do their survey to ensure that the WAAS signal (since it comes off a US NavStar GPS satellte) that the US provides is adequate for their needs. And if they want LAAS type service - they'll need to do the appropriate work there too.

As far as the approach that is flown you don't fly a WAAS approach or a LAAS approach, you'll fly a RNAV approach - either a non-precision RNAV(GNSS) or RNAV(GPS) or an approach with vertical guidance (APV) / LPV - there are lot of terms out there that I'm not totally up to speed with.

I'm out of time, but here are some linky's for you to check out.

http://www.naverus.com - they developed the RNAV(RNP) approach into Linzhi China the accompanying video is here

http://www.youtube.com/watch?v=AHF9rPWFXzw

You might want to contact them to get some more info about your airport.
Bonus animus sit, ab experientia. Quod salvatum fuerit de malis usu venit judicium.
 
Fly2HMO
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RE: The Next Generation Of ILS?

Thu Oct 08, 2009 2:13 am

Yay! Here's a thread where I can test my CFII knowledge in NextGen nav procedures before I get too rusty! I hope I don't suck  

Bear in mind, everything mentioned in the following is applicable to the USA, elsewhere I wouldn't know, but I'd assume things would be similar due to international standardization.

Quoting Norlander (Thread starter):
the Local Area Augmentation System, which currently appears to be qualified to Cat I ILS accuracy

LAAS is now actually an obsolete term. LAAS was initially supposed to cover CAT1/2/3 apps, but WAAS was found to have sufficient accuracy to do CAT 1 approaches. WAAS approaches are those marked in charts with LPV minima and the DH is 250ft, just 50ft more than your average CAT1 ILS. I've flown many WAAS approaches and they're really easy to fly, and ILSs aren't *usually* even that hard...

What was once LAAS is now called GLS (GPS/GNSS Landing System). It's the exact same idea and system as LAAS, to be used for CAT2/3a but with a different name and these approaches will have their own separate charts.

Quoting Norlander (Thread starter):
but for this system to be of any real benefit we require Cat III ILS accuracy, so that aircraft can land in zero visibility.

GLS has been shown to allow CATIIIa minima, CATIIIc is capability is being studied IIRC.

Quoting Rwessel (Reply 1):
WAAS should eventually do CAT I

WAAS has been capable of that for several years now. In fact there are more CAT I WAAS approaches today than ILS approaches.

Here is the most curent AIM NAVAID section, lots of good stuff regarding this topic:

http://www.faa.gov/air_traffic/publi...pubs/AIM/Chap1/aim0101.html#1-1-21

[Edited 2009-10-07 19:15:53]
 
dw747400
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RE: The Next Generation Of ILS?

Thu Oct 08, 2009 2:37 am



Quoting Norlander (Thread starter):
which currently appears to be qualified to Cat I ILS accuracy, but for this system to be of any real benefit we require Cat III ILS

I don't understand why you feel it is only a real benefit to be Cat III? Cat III is used very rarely, and many operators aren't even certified for it (or Cat II for that matter). Going from a VOR or NDB approach to Cat I minimums is in my opinion one of the greatest achievements of GPS to date.

Lower minimums are obviously better, but BCAT I minimums are, in my experience, rare enough that I hardly even think about them. Many of the operations I work with got rid of their Cat II training because it is costly and rarely used.
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pilotpip
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RE: The Next Generation Of ILS?

Thu Oct 08, 2009 3:44 am

The biggest place that Cat III helps is dispatch purposes. Even with Cat I you can go 100' below DH if you have certain visual cues in sight.

In 3 years I've shot an approach to minimums three times. Once I went missed, twice I've used the extra 100' and landed. More often than not if it's that low the weather is so bad I wouldn't want to try anyway.
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KELPkid
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RE: The Next Generation Of ILS?

Thu Oct 08, 2009 4:33 am



Quoting Norlander (Thread starter):
What options would be best for an airport like FAE in the near-future (5 years), given the less then ideal physical parameters of the airport, as well as budgetary reasons (it's a fairly small airport). I'm under the impression that navigational aids are developing fast, at least from my time doing remote sensing work, and thus I'm confident that there will be a perfect system for us in the near future, but unclear on exactly what that system will be.

Are LDA approaches used in places outside the USA?

Have a look at this one:

http://204.108.4.16/d-tpp/0910/00349LDA6.PDF

Basically, an LDA approach (LDA stands for "Localizer-type Directional Aid) is a localizer that doesn't take you to within 15 degrees of the runway heading. The one at ROA is unique in that it also has a glideslope in addition to the localizer, it is kind of like an ILS with much higher horizontal visibility requirements, and a little higher ceiling requirement than the usual 200' AGL...
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
Norlander
Topic Author
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RE: The Next Generation Of ILS?

Thu Oct 08, 2009 3:23 pm

Thank you all for the replies. I'll look into the links you all provided.

Quoting Dw747400 (Reply 4):
I don't understand why you feel it is only a real benefit to be Cat III? Cat III is used very rarely, and many operators aren't even certified for it (or Cat II for that matter). Going from a VOR or NDB approach to Cat I minimums is in my opinion one of the greatest achievements of GPS to date.

Mostly because what I feel is our biggest problem, is the cancellations due to low/zero visibility. Storm systems are easier to deal with, one knows when they are coming, and can plan accordingly, but the fog comes and goes, and the unexpected 2-5 days in a row cancellations during the summer, because of fog, really puts a damper on the economic growth of the Islands.

Cat I ILS has been a possibility at FAE for the last 15-20 years, but the equipment sits unused in boxes at the airport... This is partly because there was a rush to buy something they believed could help, instead of something that actually could help.

Here is an informative video by JustPlanes, that provides some information about the RC operations. From approx. 1:40 to 3:40 the pilot explains some of the factors at FAE, and there is a good view of the plane coming in to land on a relatively clear and fine day.
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hotelmode
Posts: 179
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RE: The Next Generation Of ILS?

Thu Oct 08, 2009 6:11 pm



Quoting Dw747400 (Reply 4):
I don't understand why you feel it is only a real benefit to be Cat III? Cat III is used very rarely, and many operators aren't even certified for it (or Cat II for that matter).

Maybe not in the US, but its very common in Europe and most operators are certified.

FAEs main operator flies aircraft that can go down to 50ft DH so it may be worthwhile there.
 
MSNDC9
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RE: The Next Generation Of ILS?

Thu Oct 08, 2009 6:46 pm

Quoting Dw747400 (Reply 4):
I don't understand why you feel it is only a real benefit to be Cat III? Cat III is used very rarely, and many operators aren't even certified for it (or Cat II for that matter). Going from a VOR or NDB approach to Cat I minimums is in my opinion one of the greatest achievements of GPS to date.

The LAAS systems could not meet the fail safe tolerance requirements for CAT II and III and were sent back to RND. At present, LAAS (or GBAS - or whatever...) is actually less accurate than ILS. That should change in the next coupled of years as more money is spent on it.

People should begin to lower their expecations a bit on what augmented landing systems will be able to provide. Yes, it will be able to overlay ILS, yes it will enable curved and complex approaches - BUT - the ability to provide an approach is still tied to an obstacle surface only marginally different than that used for ILS procedure establishment and the approach must also meet certain maximum turn radii and glidepath angle requirements.

The killer app isn't LAAS/GBAS/GLS/GNSS/DGPS - its forward looking infrared. Existing WAAS with FLIR is already better than ILS CAT III. Its expensive, but it is the future.

Quoting FLY2HMO (Reply 3):
What was once LAAS is now called GLS (GPS/GNSS Landing System).

Or GBAS... How many times can they change a term in 10 years! LOL...

[Edited 2009-10-08 11:51:31]
 
Fly2HMO
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RE: The Next Generation Of ILS?

Tue Oct 13, 2009 1:38 am



Quoting MSNDC9 (Reply 9):
its forward looking infrared.

This system just has so many advantages to it, yet it is still seemingly the underdog and people have been slow to adopt it save for a few bizjets and GA planes.

Quoting MSNDC9 (Reply 9):
Or GBAS... How many times can they change a term in 10 years! LOL...

Seriously, the FAA just won't make up its mind  Yeah sure
 
MSNDC9
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RE: The Next Generation Of ILS?

Tue Oct 13, 2009 6:42 pm

Quoting FLY2HMO (Reply 10):
This system just has so many advantages to it, yet it is still seemingly the underdog and people have been slow to adopt it save for a few bizjets and GA planes.

Its my understanding its a 787 option for about $150k. Maybe we'll see it go mainstream finally.

[Edited 2009-10-13 11:43:33]

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