Augmented GPS approaches
 

LPV approaches are based on WAAS satellites which augment the GPS signal. These are known a Satellite Based Augmentation System(SBAS) which sends a correction signal down the the aircraft GPS unit to correct for GPS satellite signal errors for such things as the bending of GPS signals by the atmosphere. This allows the aircraft GPS system to use GPS signals for vertical flight path creation on approach allowing lower minima.

The next stage of development is supposed to be GBAS which is ground augmentation where a ground based system at the airport would send out the appropriate correction signal.

I was under the impression that this was not in use yet but I just read an article that says "Currently, a number of private category 1 GBAS units are installed at test locations in the US and other parts of the world, but only one, in Germany, is understood to have been certified for exclusive use by a specific airline".

Anybody know which airline?

Dunno really, however Air Berlin was the first airline in germany to have been fully certifed for GBAS approaches down to CAT I minima (737 fleet only), certification date was november 2009, trial approaches in normal line flying have been done since 2006. in germany bremen (EDDW) has two GBAS approaches to those limits which are normal approaches for air berlin, although they don't have many flights there at all. As far as i know Lufthansa is working on getting GBAS certified as their new aircraft (A380 and B748) are equipped to use those approaches. However there is no hurry apparently as neither of their hubs has an GBAS installation yet, although both are working on it. Braunschweig (EDVE) has a GBAS test installation which is used for CAT IIIb trial flights, they used Air Berlin 737-700s for some of the test flights, apparently autoland/rollout works like a charm with GBAS.

As far as i know GLS/GBAS equipment is either standard or offered at no extra cost on 737s since around 2005. For the A320 it is only available as third party retrofit at considerable cost, but that may chance with the NEO variant. Apart from that it is standard Equipment on the 787 and 747-8 as well as the A380 und A350.

When flying a GBAS approach it is quite apparent that the approach is more stable and "smoother" than a normal ILS, especially if other aircraft are preceding on the ILS to the same runway, since there is absolutely no signal distortion and no need for any protected areas. It is more apparent when using the GBAS approaches into Malaga (LEMG) than in Bremen though. Malaga is still a trial procedure though, apparently certification of that installation had to take a backseat during the spanish financial crisis.

Denti:

No taxiway protected areas to guard against signal distortion. But, all the other ILS protected areas remain with LPV.

Interesting, doesn't seem to apply to GBAS though. Still surprised that LPV which doesn't even have a ground installation requires protected areas. However, LPV does not have any commercial relevance at all over here, neither does GBAS yet but that will come, especially once they are low vis certified.

Yes Denti, that is correct, the 2 WAAS sats are CONUS only for WAAS RNP 0.3, and WAAS LPV, but you get some limited coverage down into S America., I dont know of any plans to float others.

As far as protected areas, not sure where that is going, since GBAS isnt a beam, there is not interferance either from structures or other aircraft like the ILS. You can also have simultaneous arrival and departures, as there is no beam to block...

Currently, HoneyWell SmartPath is only certified CAT I, but are working on the other certs. Right now, as far as I know, Smartpath is the only GBAS system that is certified. The Russians had one, but rushed development before the ICAO specs were done, so the system they have will not work with the others...
I know a few military entities that GBAS to CAT III autoland, and yes it does work perfectly.

Now, both Airbus and Boeing offer the GBAS "option' for free with all current models when ordered new, you just have to ask.

Unfortunately, due to the budget fiasco with the FAA in the last few years, the FAA has given up on GBAS, as redundant to WAAS. This is most unfortunate, as the capabilities are completely different.

While the WAAS augments the GPS signal, and provides a fine tuning...GBAS augments GPS, but also adds the final approach procedure, even to include a turn to final.
I was able to provide multiple GPA's, displaced thresholds, final approach with a turn, or the best scenario was RNP transitions to a GBAS final...perfectly seamless.

The FAA was stung by using Newark as a test, because the freeway next to the runway was full of trucks with GPS jammers, so they were constantly losing the signal.
There was another installed at Memphis, but the FAA let that one die, and go non-op. Looks like it is being resurrected at Houston to further Continental (United) use of the system to pair their Newark/Houson flight op..
Boeing has one installed at Moses Lake for validation purposes.
You mentioned Bremen, and Malaga, and there is also Sydney still operational.

Given the system capabilites, I really find it difficult to understand why it is not more widespread. It doesnt help that the FAA is out of money, or that while the SmartPath is Honeywell, you have to use a Rockwell Collins MMR on the aircraft...now who didnt figure that one out? :ugh:

Denti, why do you say that LPV is irrelevant in Europe?

LPV is definitely being used in Europe by commercial operators. Aurigny were the first to use the LPV approaches into Alderney in the Channel Isalnds on their BN Trislander fleet.

What satellites is Aurigny using for augmentation of the GPS signal

EGNOS. Alderney's published LPV approach went live in November 2011 and the STC for Garmin GNS430W approval in the Trisalnder fleet was issued a couple of weeks later to Gama Engineering Ltd.

OK465,

no tango dinero....

it is about as relevant as NextGen :\

Last news update was 2008....

Navigation Programs - GBAS - News

I have not heard of anyone looking at GBAS procedure designs in the US since Newark...and I work with Honeywell SmartPath...perhaps when Houston comes online...All of the work I know of has been only in certification.

The RNP to GBAS procedures I know of are in China..as well as a departure procedures.

FlightPathOBN:

Have you checked all of the LPV approaches in Alaska?

Also, Mexico has adequate vertical coverage, but the presumption is they would have installed a ground reference station. So far, "No Senior."

I suspect below Mexico it is like Hawaii, good horizontal coverage but lousy vertical.

It also shows 5 for Newark... I know they were working on the installation/cert at houston, I just havent tracked if it is up and operational yet...I have not heard of anyone using the procedures...

yes terpster, that is correct, there are many in AK...( I just usually lump them in with CONUS, as CA is a wholly owned subsidiary)

and you are also correct, while the sat coverage does cover other areas and down to S America, there are other requirements for them to actually use it in these countries...

1. What triggers a GBAS autoland warning light? Haven't found anything in the FCOM about that.

2. What are the Required Equipment requirements for a GBAS approach?