WAAS GPS approach question.

On Fri, 21 Apr 2006 01:53:42 GMT, "soxinbox" wrote:

I thought the FAA approved the use of GPS for any NDB waypoint.

They did. But note the word "waypoint"


A plane
without ADF can fly any ADF approach with a IFR approach certified GPS. GPS
waypoints can also be used in lue of ADF for missed approach holds, so you
can fly any approach that has "ADF required" without an ADF if you have an
IFR certified GPS.

Note this from the AIM: (emphasis mine)

"(6) Charted requirements for ADF and/or DME can be met using the GPS
system, **EXCEPT** for use as the principal instrument approach navigation
source."

This would be true for a stand alone NDB approach (i.e. with no GPS
overlay); and for the primary DME approach at Martin State (near BWI).

If there is a published GPS overlay, that would be different. But not all
NDB approaches have GPS overlays.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)