On Tue, 15 Jun 2004 15:52:56 -0700, "Bob Gardner"
wrote:

An article (actually, a sidebar to an article) in the July IFR magazine says
"According to AIM 1-1-20 (f)(7), by omission, you can't just input the VOR
as the active waypoint....," and "...according to this passage, the FAA
allows GPS to substitute for everything except for a VOR. For some reason,
the FAA has faith in its VORs and won't let you substitute GPS for them as a
primary means of navigation."

Bob,

I cannot find that paragraph.

AIM 1-1-20 refers to WAAS boxes certified under TSO-146, which do not
require any other type of navigation equipment to be on board and can be
used for enroute navigation using VOR's (and airways, for that matter),
without a VOR receiver on board.

You (or the July IFR magazine -- haven't seen it yet) are probably (or
should be) referencing 1-1-19 which refers to TSO 129 boxes. Those do
require an alternate means of navigation to be on board.

But, not having read the article, I would disagree that one cannot use
VOR's as the active waypoint in a TSO129 box that is approved for GPS
approaches. It makes no sense so long as the VOR is retrieved from the
box's database. Since that same box can be used to fly overlay approaches
based on a VOR, to claim that because the substitution is omitted in 1-1-19
(f)(7) that it is not allowed, makes no sense. It is certainly allowed in
performing the overlay approaches.


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