It is nice to see this technology finally being adopted by the airlines. After using it for 7 years in the US, I don’t fly no stinking ILS, too much work!
It’s completely ridiculous that airliners are only reportedly just starting to use this.
But I don’t think this is the whole story, because according to one airline pilot I used to fly with, for some years they have been using three GPSs to correct the INS on the Atlantic routes.
Admittedly that’s not EGNOS so not related to LPV capability. But LPV gives you only Cat 1. How to they do Cat 3? Below about 150ft a RADALT takes over for VNAV, while the LOC is tracked for LNAV. So for a Cat 3 LPV they would need to do something similar.
But LPV gives you only Cat 1. How to they do Cat 3
Instead of WAAS, you need to use GBAS (Ground Based Augmentation System). There are actually a handful of GBAS (aka GLS) approaches around the world, but for now they are all Cat 1: http://flygls.net/
The 787 and 747-8 come with GBAS installed as standard. This (local copy) AIP Sup from Australia has a whole load of operational detail.
Peter wrote:
Below about 150ft a RADALT takes over for VNAV
More like 50 ft.
To be precise, the Cat III autoland system will deselect G/P at or by 133ft RADALT (1600ft from touchdown point). The aircraft will enter Attitude Hold Mode (it basically selects the average attitude attained during the previous 10 seconds) and continue at this attitude until 70ft RADALT. At this point the system will change into FLARE mode where the computers will select a predetermined rate of change of attitude to achieve a maximum attitude together with a power retard. Throughout the LOC element of the ILS system is continued to be used for lateral guidance.
Hm. This is in contradiction to what the Oxford ATPL manual says. “At … 50 ft RA … the FLARE mode is automatically engaged (replacing G/S) …” But it may differ between different systems, I guess.
Nope, they’re all broadly the same. I could show you a G/P calibration graph which would clearly show why using G/P below about 100ft isn’t clever as it will either give you a significant ‘fly-up’ or, even worse, a ‘fly-down’ (My current day job is a navigation aid flight calibration pilot).
This is in contradiction to what the Oxford ATPL manual says
I am shocked 
I am advised by an ex CAA / RAF guy that that material is mostly ex Royal Air Force, thrown out by the RAF is irrelevant in the 1960s and picked up by a former RAF mechanic who positioned himself in the late 1990s (as JAA was being formed) as having the only “approved” ground school.
I recall doing that at GTS in 2011. There was some 1970s stuff on inertial nav, so it has been updated since the 1960s.
Peter wrote:
I am shocked
To be fair, quite a bit of the Oxford stuff is still very good; meteorology and PofF for example.
