The ILS is dead. Long live the WAAS!

[EHM-1749 Hector]

The passengers aboard a Horizon Air flight to Portland in late December got there on time and made history in doing so. They were aboard the first Part 121 passenger flight to complete a WAAS Localizer Performance with Vertical Guidance (LPV) and without the satellite-based gear they would likely have ended up somewhere else. It was a typical winter day in the Pacific Northwest and the ILS was out in Portland so only aircraft with WAAS-capable GPS gear aboard were getting in. Horizon, which flies in some of the most challenging terrain and weather anywhere as the regional arm of Alaska Airlines, is equipping all its 40 Bombardier Q400s with Universal Avionics' WAAS-enabled flight management systems, enabling them to fly any WAAS approach, improving accessibility to airports on their routes and giving greater flexibility in picking alternates.



The STC for the WAAS gear (Universal Avionics UNS-1Ew WAAS/SBAS-FMS) in the Q400 was obtained by Canard Aerospace Corp. on Nov. 23 and the first revenue flight was flown the morning of Dec. 30. The Portland approach happened that afternoon. There are now 1,884 published WAAS approaches and it's expected the gear will become a fixture in airline cockpits as part of the NextGen program.

[EHM-2097 Andrei]

I wonder whether the captain told the passengers they are about to use the system for the first time 

I know, I know, it has been tested lots. I know, but maybe they don't

On a more serious note, I understand that unlike the ILS, which depends heavily on ground equipment, the WAAS works with GPS so it will never be unserviceable on any given airport? This would be great news...

On the other hand, the ILS "beams" exist materially so either these don't work at all or they point to the right location. Unlike this again, GPS coordinates are just numbers so a wrong bit anywhere would spell disaster. Of course this is very unlikely to happen, but this is just another bit of our lives that goes "digitized". Now how much is just too much? I hope not to learn it...

Unless the "Butler jihad" comes and reverses the process (I hope enough people here are familiar with the term  - and no, it's not about Middle East)

Andrei

[EHM-1465 Dominic]

Unless the "Butler jihad" comes and reverses the process (I hope enough people here are familiar with the term   - and no, it's not about Middle East)

Andrei

Sorry mate, you've lost me there - what does that mean?

As to the new system, I've also heard that MLS was going to replace ILS - based on microwave emitters this is supposed to be more reliable in all conditions than ILS systems. Don't know the relative strengths and weaknesses of each system though

[EHM-2097 Andrei]

Sorry mate, you've lost me there - what does that mean?

It's "Dune"   . This "jihad" is mentioned as an event in  the (their) past, when people decided to ban all form of computers due to the risk of human lives getting over-controlled by these. Not something that could happen tomorrow but not a completely unlikely course of events either...

Sorry for thread hacking  

Now about ILS vs. MLS, I don't knoe very well either but one thing I know for sure: due to different wavelength, microwaves travel through the air differently from radio waves so they behave differently in respect to obstacles & obturations. Just a guess however...

Andrei

[EHM-1465 Dominic]

Aha - Dune! I've seen the film about 12 times but not read the books and it never completely makes sense to me 

You're right about MLS too, it's supposed to not be affected by certain obstacles that can make the ILS less effective at certain airports or certain times. But the GPS based system should be even better I guess...