Michael_J wrote:
It worked like a charm
They do, even on new AP: LPV is smooth like silk all the way to the other end (tried it load of times in VMC)
Of course LPV is smooth 
It is the autopilot which might not be.
It is the
autopilot which might not be
corrected
The airlines may not be using LPV but a year ago when I was still flying around KSJC (San Jose CA) all the clearances I heard were for RNAV and not for ILS. There again I wasn’t flying on days when an LPV would be to mins, because there weren’t many of them.
It is IME normal for airlines to request an NDB / DME / VOR approach when in reality they are flying an FMS-synthesised “ILS”, and have merely checked the requested navaids are not a) notamed INOP and, in some AOC ops, b) check the navaids idents. But they have to request “something”, haven’t they? What they actually use for L+V guidance is an internal cockpit matter.
It’s no different to a GA pilot to request an NDB/DME approach when actually using a GPS, particularly if not having the approach approved AFMS (probably most GA doesn’t have that anyway) and that way you are legal on the radio recordings.
The airlines with very few exceptions have not equipped with WAAS systems, so almost no experience at all with LPV
There was a pilot here (now sails a boat, like so many ) who flew a 787 and said it can do GPS/LNAV but not LPV. It had no SBAS (WAAS) capability… But some smaller jets probably do have it now.
NCYankee wrote:
The airlines with very few exceptions have not equipped with WAAS systems, so almost no experience at all with LPV.
Indeed, the majority of B737s regional fleet in Europe have L/VNAV with BARO not LPV with SBAS (Airbus has gone “slightly different” as they received money to sponsor ways to upgrade the fleet), the most worrying thing is few guys flying them saying they are LPV equipped !!
Ibra wrote:
the LPV was norm in US since 2005 and LNAV was norm in Alaska since 1999 and there was lot of “technical need & expertise” in those corners
US started with overlay of conventional approaches in 1996 named for example “VOR/GPS” and later changed to “VOR or GPS”. These were to an LNAV MDA. Later FAA started designing GPS stand alone procedures named “GPS”. Then the RNAV (GPS) standard was adopted with LNAV MDA. WAAS was first enabled in 2003 but there was only the UPS Apollo CNX80 GPS that was capable of flying an LPV and it was not approved for LPV until 2004 after Garmin purchased UPS Apollo. The Garmin version was renamed GNS480. These units were not numerous and there were only about 5000 ever sold and installed. Around the same time there were approximately 100,000 of the legacy GNS430/530 units, but they were not WAAS. Garmin released the GNS430W/530W at the end of 2006, but there were not many upgrades until 2007 and 2008 when Garmin released its WAAS upgrade for the existing GNS 430/530.. The original LPV had a DA of 250’ or greater and by 2008 there were about 1000 LPV procedures published. By late 2008, the FAA started publishing LPV200 procedures. Virtually all GPS overlay procedures were eliminated when the airport added RNAV procedures (mostly straight in) leaving just the conventional procedure without the overlay option. Now there are almost 4800 LPV charts published with over 1100 LPV 200 and over 700 LP procedures without vertical guidance. All of these approaches comply with the RNP APCH PBN Nav specification.
Thanks for the historical background, yes it started in 1996 when FAA approved first RNP in Alaska and the rest followed
I recently heard rumors that LPV (maybe even CAT I) will eventually be supported by GPS without SBAS/WAAS. Supposedly because the “base” GPS is steadily improving its precision. Does anyone know?
I can’t see how that is technically possible?
The legacy non-SBAS GPS are TSO129 with linear CDI deviation rather than angular CDI deviation, the LPV has to be angular CDI to be equivalent to Cat1 ILS
The new TSO146 GPS should be capable of LPV specs even when SBAS signal is not available, on these boxes, LNAV+V and LPV are very identical in terms of (angular) geometry if the magneta line is in middle but LNAV minima has to be backward compatible with legacy TSO129 boxes: higher surveyed (linear) area which raises LNAV minima, other than minima and protected surface, the only difference betwen LNAV+V and LPV is alterting tolerances…
However, even without SBAS signal, nothing prevents a TSO146 GPS to annuciate LPV if the final leg is coded as such in database, assuming RAIM checks predicts signal to stay within LPV H/V tolerances, @NCYankee ?
Ignoring obstacles surface & height minima, the only benefit of SBAS signal itself is position correction (which could be tiny anyway) and passive monitoring on ground: NOTAMS and monthly reports of GPS performance at AD
As far as I am concerned, the difference between APV & LPV in Paris is zero 
