Being asked to "verify direct XXX"

The AIM is not regulatory and there is no requirement that limits usage to
authorized units.

That is definitely incorrect. TSO-C129. GPS units
have to be certified to use under IFR. Otherwise
I could pick up a golf ball on a string and call
it an attitude indicator and say that meets the minimum
requirement for an AI under IFR flight. Or I can pick
up a sextant and call it a FMS and then file slant-whatever it is.

I spent literally 2 minute searching but couldn't find that TSO
but this is from the FAA and has many references saying
that GPS's are required to be certified for use under IFR.

http://www.faa.gov/avr/afs/faa/8400/...4/4_001_02.pdf

I'll have to do some more research to find the exact regulation.

I do realize that the AIM is not regulatory but
GPS's definitely need to be certified otherwise some
GPS's (Garmin 430 which I"m most familiar with) wouldn't
need to be placarded as "VFR only" when the owner didn't
go through the IFR certification for the unit.

Do you base your life off of something completely untested?
Are tested units failure-proof?

absolutely not but at least they have been tested and designed
to a standard for aviation use and no standard other than being
light, convenient and as cheap as possible for the hiking crowd.
What you are saying is my Garmin V designed for automobile
navigation is legal to fly under IFR even though it updates
about once every 4 seconds.


Another person wrote:
My sextant isn't authorized either. Doesn't mean I can't use it to
navigate under IFR.

incorrect unless there is a TSO for it.

and just what is "situational awareness" anyway?

Well navigation is being able to follow a vector
(speed and in 3D). The situational awareness is what is happening
elsewise such as are mountains nearby, how high above the ground
you are, weather, etc. the both are helpful to know of course but are
independent. You can navigate by being at the right position all day
long without knowing what the heck is going on around you.

Lastly, I have to admit I'm far from an expert. In fact
my IFR checkride is in 2 weeks. But this stuff is almost a given.


Gerald Sylvester