GPS approach question

Roy Smith wrote:

Matt Whiting wrote:

I also flew the VOR-A approach, but not its overlaid GPS-A approach. I
see that the chart shows what appears to be a MAP wapoint, MAGNV. This
is listed in parens at the location of the runway. I don't find this in
the terminal procedures legend, so can someone confirm that (MAGNV)
really is intended to indicate a GPS waypoint? However, again it has no
MAP WP symbol beside it, but if it isn't the MAP waypoint I can't figure
out what it is.


Waypoints in parens, like (MAGNV) are Computer Navigation Fixes (CNFs).
They're waypoints which only exist in your GPS database (and on the SIAP
charts). They are not marked on the controller's radar display. If you
told the controller that you were "2 miles east of MAGNV", he wouldn't
know where that was. That's the explanation of what they are; as for
*why* they exist, I have no idea. See the AIM 1-1-19-k-2 for more
details.

Thanks, the AIM was the next stop on my journey. I read the GPS section
back in the spring, but obviously didn't remember all of the requisite
details!


MAGNV sure looks like the MAP to me. Although I can't find the
reference now, I vaguely remember reading that CNFs used as MAPs all
have names starting in MA.

Yes, it appears to be the MAP, but it doesn't have the map symbol beside
it so I'm not sure.


Matt