I went testing my new Avidyne DFC90 autopilot today (very good product) and chose the neighboring airfield Schwäbisch Hall EDTY because it's got an ILS. After two ILS, I wanted to try the RNAV 28 and surprise surprise, there was an LPV 28 approach in my GNS430W, even though there is no Jeppesen plate yet. AFIS knew that something was coming but no details, also not the DH (only that it will be more than the 200ft AGL for the ILS initially).
My combination of Aspen PDF, Garmin GNS430W and Avidyne DFC90 makes flying LPV approaches much easier than ILS. Previously there were multiple sources of error, most notably the GPS/VLOC switch on the GNS, the auto-slewing of the CRS pointer and the mode of the autopilot. One had to know when to switch from HDG (= GPSS) mode to NAV mode and it wasn't always pretty because the NAV based intercept algorithm is by far not as elegant as the GPSS method. If the switch happened to late, it would not want to intercept the GS.
I loaded and activated the LPV approach and chose DKB as the IF (vectors to final also possible). At the approach altitude of 5000ft, I pushed ALT and GPSS on the autopilot. It flew to DKB and sequenced all waypoints until final approach (just like with the ILS on GPS overlay) and then automatically switched the autopilot to approach mode, captured the GPS localizer and a bit later when I approached the GPS glidepath also automatically captured the GPS glidepath and started descending. I set the DA for an alert and watched it do its job. The ILS indicator was running in parallel and the LPV was identical to the ILS. There was a lot of thermal turbulence today so a good test. I found both the ILS and the LPV to be rock solid with no notable difference between the two, maybe the LPV was a bit smoother in short final with smaller corrections. The LPV worked all the way down to the runway which is not authorized of course.
Great stuff, keep them LPV approaches coming! A lot of money could be saved by moving from ILS to LPV and a lot more airfields can get instrument approaches.
I know the Americans will laugh about this but so did we when we saw the happy faces of East Germans in 1989 that got their first banana 
Sweet.
I haven't flown an actual ILS in IMC for at least 4+ years, just practice to keep up the skill. I gave up practicing VOR approaches before that and the ADF has been out of my airplane since 2000. Currently here in the US, the inventory of approaches indicates there are 3160 LPV procedures and only 1283 ILS installations. In each of the locations where there is an ILS, there is a LPV, often to the same Category 1 DA as the ILS.
They are great. And congrats on the autopilot. I loved mine.
Have you seen the minima lines at EDTY though?
LNAV OCH 450 ft
LNAV/VNAV OCH 370 ft
LPV OCH 450 ft
[edited for formatting; to force a line break without using blank lines, put 2 spaces after the line]
Another weird LPV above LNAV/VNAV result.
The OCH seems to always be higher than the system minima?
Posted here but partly in response to the request on another thread to the question what is an LPV. This is a good overview, albeit from a Honeywell training video.
https://aerospace.honeywell.com/landing-pages/training-tv
The above links to the menu list. You want the Primus Apex PC12 and Localiser Performance with Vertical Guidance item. Below is the you tube link.
I tried a couple more LPVs and LNAV/VNAVs … and i guess wherever possible i will only fly those in the future …
Great stuff Achim!
I noticed with interest that you now get AP and mode announciations on the Aspen: Is this a function of the Avidyne AP? That is really neat. I can’t get this kind of indications for the 55X.
Yes, LPV approaches are great. The test crew who did the certification flight on my airplane did a trial approach in VMC in Donaueschingen and said they could stay coupled all the way to the runway with huge accuracy. Of course this is not the idea but it is interesting to know that these approaches are that accurate and the hardware can actually live up to it.
I use a G1000 trainer on a PC. I’d like to train with it but I could not find any airfield with a GNSS approach.
It’s an old version (circa 2008) so I should try an airfield which had a GNSS approach published a long time ago. What is the airfield with the oldest GNSS approach?
