Originally Posted by
Ascend Charlie
...this as a "Twopence and threepence" approach?
Love it - I'm doing tup-pence and thrip-pence approaches from now - but only with old guys who know what a pence is.
For those seeing it for the first time - 2D equates precisely to
non-precision approach; has only indirect vertical guidance (using time or distance), and has an MDA. 3D equates to a
precision approach; vertical guidance (glideslope) shown on the instrument
and has DA. If it doesn't have a DA or if you're not seeing a GS, then it's a 2D.
And as a postscript, L/VNAV with vertical guidance from your baro-aided GPS needs specific approval - you can't (legally) just do it because your fancy glass cockpit can do it; it's not included in the strange list of approaches you're deemed capable of by virtue of having a GPS. (You didn't think it would be that easy!)