Originally Posted by
Torquetalk
Yes, LNAV isn’t affected by this as you say. And as GPS will do the job, those pesky burocratic Europeans can keep their satellites. Fortunately the UK has a pragmatic government that has thought all this through in the years it had to consider the ramifications of Brexit. And its not like it would let stuff like this happen through lack of preparation or to cut off noses our to spite the EU’s face.
A lot of 2D LNAV approaches are flown coupled baro VNAV, because FMS systems default to this when LPV is not one of the approach options. As we fly CDFAs, there really should be no effective difference as you say. More a question of which minima you are flying to. But it begs the question as to why you cannot fly couple baro-VNAV if your aircraft are IFR certified and otherwise capable of SBAS coupling. Is it because the certification standard for 3D guidance does not extend to the pitot-static system, or that it does not feed into the AFCS?
If the VNAV approach using the EGNOS signal can still be selected, there is little doubt that this is exactly what a lot of people will do. But this is why I believe the database providers will programme this out until the matter is resolved. I mean, seriously, you can’t have people flying down to CAT 1 minima using a system which isn’t bedded in a regulatory framework of agreements. And the use of the only augmentation signal hasn’t.
What they might do is code the approaches as they were before 2018. LNAV/VNAV wouldn't load on an SBAS receiver unless you had baro VNAV (I think its via means of changing one parameter on the approach to allow angular vertical VNAV - bit rusty on my ARINC 424 coding).