Cap'n
I just cannot agree with you on this. OK, so I only peddle a Bonanza around the place these days, but it has similar approach performance to a bunch of other stuff.
I do GPSRNAV Apprs all the time, and have flown the same LHR appr in sh*t weather (admittedly with my heart in my mouth since the prang) several times.
Is there an equipment issue here?
I did my initial GPS NPA endorsement with a King GPS that I found to be less than friendly, but I love the Garmin 430 in my Bo.
I usually let George (Century III) fly the approach, and I have the pictorial display of the appr on the 430. I set the aircraft up as I would for an ILS with 10 flap and 120 kts, then drop the gear at the point indicated on the chart for the start of the 3 degree descent to ""Mike".
In my Bonanza, 10 flap, gear down, 23/23 gives me a 3 degree descent path - 120 kts, 600ft/min.
(I flew a new C172 to other day that had a King autopilot that would hold a preset ROC or ROD - would love to have me one of them! Flew a fully coupled ILS appr in 22 kt Xwind - it had the needles nailed in the centre all the way to the runway!)
It wouldn't matter a damn to me if Foxtrot was there or not, because I can see on the pictorial display where I am on the appr. I suppose it does give you a check altitude, but the terrain alert in the 430 keeps an eye on that for me.
I would not want to see Oz go to a non-ICAO std GPS NPA Appr. If there genuinely is a problem - change the ICAO standard.
Dr