"GPS Unreliable" NOTAM

On Mon, 21 Jul 2003 14:14:57 -0400, "Ron Natalie"
wrote:


"Richard Kaplan" wrote in message ...

With that as background, look at the following NOTAM, which is currently
available on DUAT. We can theorize all we want about whether this NOTAM
exists due to military testing or some atmospheric irregularity or whatever,
but the point is that the NOTAM really is out there and will be effective in
a few days. If my plane had nothing but GPS-based avionics, what would my
options be?

From my discussions with some stationed there, it is airborne GPS jamming testing.

Seeing those NOTAMS is not rare. Some have mentioned testing. Most
are in the western states, probably as it would cause less disruption.

I've done five flight plans this year that were direct 3BS BJC and 4
of them had GPS NOTAMS which included the expected distances from the
area versus the altitude.

GPS may be the best thing since fried eggs, but it's still a good idea
to keep something for back up.

Contrary to an earlier statement, the back up system does not have to
be more reliable than the primary system. It doesn't even have to be
as good as...As long as the failure rate is low enough, the odds of
both systems going out at the same time are very low.

"Last I heard" the FAA had backed off on the GPS only idea and is
considering carrying the VORs for some time to come. With some form
of backup in the future.

Last week I read where they had just commissioned a new NDB/LOM
I believe AVWeb had a story on the WAAS and how long it will probably
take to get it widely implemented.

A big advantage for WAAS is "as I understand it", one station can
service a number of nearby airports.depending on distances and
minimums.

For most of us it's not "one or the other". GPS wins hands down when
the two are compared, but there is most likely going to be a ground
based backup system (of some sort) far into the future.

I like the idea of GPS and a solid state inertial guidance
system...Which I think will show up in a form a good percent of us can
afford.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)