"G. Sylvester" wrote in message
m...

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.


TSO C-129a is available online at: http://makeashorterlink.com/?A238150FA

TSOs are not regulations, they are Technical Standard Orders. TSOs are not
binding unless there is an FAR that requires the TSO to be complied with, so
says FAR 21.601. There are TSOs in existence that cover the "approval" of a
great many things, but you don't have to use "approved" equipment in any
operation unless required to do so by the FARs. What FAR requires
compliance with TSO-C129a?



PART 21--CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS

Subpart O--Technical Standard Order Authorizations

Sec. 21.601 Applicability.

[snip]

(b) For the purpose of this subpart--

[snip]


(4) An article manufactured under a TSO authorization, an FAA letter of
acceptance as described in §21.603(b), or an appliance manufactured under a
letter of TSO design approval described in §21.617 is an approved article or
appliance for the purpose of meeting the regulations of this chapter that
require the article to be approved.




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.


If the avionics shop that installs a GPS lacking IFR certification adheres
to AC 20-138 it will affix a placard stating "GPS limited to VFR use only".
Use of a GPS with such a placard during IFR operations, even on a cloudless
day with no restrictions to visibility, would be a violation of FAR 91.9(a).
But a handheld GPS is not installed equipment.



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.


Actually, I'm just saying that which is not prohibited is legal and there's
no prohibition against use of a handheld GPS during IFR enroute flight.



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.


Please cite the regulation requiring the unit be TSO'd.