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-   -   WAAS on Boeings and Airbii (https://www.pprune.org/tech-log/546607-waas-boeings-airbii.html)

Check Airman 30th Aug 2014 05:30

WAAS on Boeings and Airbii
 
Pardon the silly question, but are modern Boeing and Airbus aircraft equipped with WAAS receivers? I'm thinking about the 787 and 380. Can they do LPV approaches?

How about the latest generation of the older models (A320,767,737) rolling off the factory floor right now? Is there an option to get new airplanes with WAAS?

27/09 30th Aug 2014 07:30

I believe WAAS is an option on Boeing and Airbus. I think it depends on what the purchaser options as to whether or not WAAS is fitted.

I know one airline in Alaska (can't remember the name) has WAAS on their Boeings, 737's I think. It twas a retro fit so far as I know. Universal have WAAS on some of their FMS units.

STBYRUD 30th Aug 2014 08:27

I remember reading in an FCTM recently that "Boeing airplanes are not equipped to utilize LPV minimums." - I suppose retrofitting WAAS and thus LPV capability would be quite costly when regular ICAO complaint RNP approaches could achieve the same thing without SBAS or GBAS.

27/09 30th Aug 2014 08:35

Here's a link to an article regarding the Alaskan 737 operation using WAAS.

http://www.faa.gov/about/office_org/..._final_web.pdf

As time goes on I'll think you'll see WAAS or perhaps more correctly SBAS becoming more mainstream in heavy jet aircraft.

STBYRUD 30th Aug 2014 09:53

Hm, makes sense to fit these ancient -200s with a capable FMS - that the GPS receivers are WAAS capable is an added bonus! But I don't see how fitting a recently delivered PBN capable plane with WAAS receivers would be beneficial to the operator - they can all achieve an ANP of less than 0.1NM anyway even without augmentation... Or am I missing something here?

Denti 30th Aug 2014 10:24

WAAS is a customer option, as is apparently GBAS. We use the latter one for the last 8 years as standard equipment on our 737s and have neither on our airbus fleet. On the 737 it was chosed to be in line with the ordered 787s where it is standard equipment in any case.

STBYRUD 30th Aug 2014 11:14

You mean the GLS capable MMRs on the newish 737s, right? To my knowledge Boeing still doesn't offer any form of SBAS (be it WAAS or EGNOS) capable MMRs as a factory option... Even GLS seems to be dying out before it was even used properly (quite like MLS), the newest 777s don't even have the option for GLS option anymore and don't come with the third GPS antenna and the GLS VDR :sad:

Denti 30th Aug 2014 11:53

You don't even need a third GPS for GLS. Two is enough. But yes, GLS is starting very slowly, although apparently both FRA and MUC are preparing installations, especially to offer several different approaches at different angles with just one installation.

As Alaska Airlines is apparently using SBAS there must be a solution for boeings, but it might be an aftermarket STC.

STBYRUD 30th Aug 2014 11:55

It definitely is an aftermarket system, since the -200s lack a factory FMS and of course also a GPS receiver... True, GLS works with two on the 737, but the older 777s were delivered with three so that each MMR gets its own GPS input for a GLS approach.

€: Duh, I should read that article first, its this thing: http://www.universalavionics.com/products/uns1fw.aspx

aterpster 30th Aug 2014 13:22

stdby:


Hm, makes sense to fit these ancient -200s with a capable FMS - that the GPS receivers are WAAS capable is an added bonus! But I don't see how fitting a recently delivered PBN capable plane with WAAS receivers would be beneficial to the operator - they can all achieve an ANP of less than 0.1NM anyway even without augmentation... Or am I missing something here?
RNP AR approaches are relatively few and require special training and procedures. And, as flexible as they can be they are still Baro VNAV approaches. LPV, on the other hand, can achieve "200 and 1/2."

One is to avoid terrain or noise issues, the other is for low minimums.

Check Airman 31st Aug 2014 01:04

Thanks guys, so there does seem to be an option. I just find it curious that more airlines don't utilize it, because it seems more cost effective (at least from a training standpoint) to utilize LPV approaches.

KJFK 22L is a pretty typical example. LPV mins are 270/2400RVR, RNP 0.2 mins are 317/4000.

It seems odd that a C172 pilot can hand fly to lower mins than the 777 crew that (presumably) has to use FD and AP.


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