Originally Posted by
custardpsc
But I didn't get Empty Cruises point about LPV minima. I know that LPV requires WAAS but if you have integrity and there are no LPV minima what stops one using LNAV/VNAV approach / minima ?
Custard - you are of course right, if you are under SBAS coverage and intend to fly an RNP-1 STAR - no RAIM check required.
The point about promulgated LPV minima still stands (kinda) - because, if you are in an areas that
should be covered by SBAS - why would you chose to not promulgate LPV minima? Obstacle clearance survey is basically the same as for LNAV/VNAV, so there is no money to save - which would make me think that something else is preventing a successful LPV implementation.
We operate in and out of SBAS coverage areas on a daily basis - so we have just decided to be done with it and always perform a PRAIM-check before departure, unless both crew agree that - yes, this is SBAS all the way.
In theory - SBAS ‘only’ saves one of the required 5 sats in visibility and decent geometry for FDE - if there is no GPS signal, SBAS is useless. So I do get your point - have been too lazy to consider it myself...