Is your IFR GPS still legal for use?

"Roy Smith" wrote in message
...

But it's legal to fly those very same approaches with a 30 year old ADF
which points vaguely in the direction of either 1) the radio beacon, 2)
the
nearest T-storm, or 3) some other random propagation anomaly, and an
equally ancient DME which is doing good if it's correct to within 1/4
mile.
Gotta love the FAA. A fine example of why getting all the government
you've paid for is a bad thing.


You can't substitute GPS for ADF on an NDB approach.

"Peter R." wrote in message
...

Admittedly I didn't read the entire circular (I have a Garmin GNS430), but
my quick skim of it seemed to indicate that the non-compliant models are
no longer allowed to use GPS in lieu of ADF or DME, where that is
applicable, unless alternate instructions are provided by ATC. This would
imply that for home-grown RNAV approaches these units would still be
legal. Did I interpret incorrectly?


I didn't read the entire AC either, but I don't see how you or AOPA
conclude that use of GPS to substitute for ADF or DME is now limited in all
cases to the cited Garmin units. The subject of AC 90-100A is "U.S.
Terminal and En Route Area Navigation (RNAV) Operations." The AC says it
"applies to operation on U.S. Area Navigation (RNAV) routes (Q-routes and
T-routes), Departure Procedures (Obstacle Departure Procedures and Standard
Instrument Departures), and Standard Terminal Arrivals (STARs)." The AOPA
letter states, "Pilots have removed ADF and DME systems from their aircraft
and they will no longer have access to any conventional approaches that
require them." I can find nothing that suggests the previous approval to
substitute GPS for ADF or DME has been rescinded for IAPs.

Recently, Steven P. McNicoll posted:

"Roy Smith" wrote in message
...

But it's legal to fly those very same approaches with a 30 year old
ADF which points vaguely in the direction of either 1) the radio
beacon, 2) the
nearest T-storm, or 3) some other random propagation anomaly, and an
equally ancient DME which is doing good if it's correct to within 1/4
mile.
Gotta love the FAA. A fine example of why getting all the government
you've paid for is a bad thing.


You can't substitute GPS for ADF on an NDB approach.

Of course not. If one did that kind of thing, they might actually arrive
at their intended destination.

Neil

I "tried" to read that AC... it is the biggest collection of gibberish that
the FAA has published in a long time. If anybody in the group needs a real
big headache, give it a shot, then report back to the group with your
conclusion.
Jim

john smith wrote in news:4656d17a$0$2829
:

AvWeb has an article in todays issue saying that only the GPS 400/500
series and G1000 are the only IFR certified navigators that are legal to
use.

From the way I am reading it, it sounds like the restriction is only for
certain types of GPS-specific procedures, such as RNAV-STARs, RNAV-SIDs, and
Q-Routes and T-Routes. I'm not sure what a Q-Route or a T-Route is, but I
have heard of RNAV-STARs and RNAV-SIDs. I've never used them up to now, and
it doesn't worry me much that I won't be able to use them with my current
GPS.

Normal routes (even off-airway, which is specifically mentioned) and normal
STARs, SIDs, and other procedures, even GPS approaches, don't seem to be
covered in this AC.

I'm no lawyer, nor even an expert, but that's how I read it...

Did AOPA get wind of a specific paragraph that is more broad than this?

In article ,
"Jim Burns" wrote:

I "tried" to read that AC... it is the biggest collection of gibberish that
the FAA has published in a long time. If anybody in the group needs a real
big headache, give it a shot, then report back to the group with your
conclusion.
Jim

some things to consider:

1) AC 90-100A only cancels 90-100. It doesn't cancel
AC 20-130A, for example, or any of the AIM.

2) The AC is for RNAV routes. This does not conflict with the
AIM paragraph on using an appropriately certified GPS installation
in lieu of a VOR, DME, or ADF for non-RNAV routes.

3) Historically, the FAA does not update advisory circulars that also
de-certify the airworthiness of existing equipment, including the
authorization to use it. If they did, the various alphabet soups and
aviation companies would NOT participate in developing new
standards, etc.

--
Bob Noel
(goodness, please trim replies!!!)

On Sat, 26 May 2007 17:38:54 GMT, Judah wrote:

john smith wrote in news:4656d17a$0$2829
:

AvWeb has an article in todays issue saying that only the GPS 400/500
series and G1000 are the only IFR certified navigators that are legal to
use.

From the way I am reading it, it sounds like the restriction is only for
certain types of GPS-specific procedures, such as RNAV-STARs, RNAV-SIDs, and
Q-Routes and T-Routes. I'm not sure what a Q-Route or a T-Route is, but I
have heard of RNAV-STARs and RNAV-SIDs. I've never used them up to now, and
it doesn't worry me much that I won't be able to use them with my current
GPS.

Normal routes (even off-airway, which is specifically mentioned) and normal
STARs, SIDs, and other procedures, even GPS approaches, don't seem to be
covered in this AC.

I'm no lawyer, nor even an expert, but that's how I read it...

Did AOPA get wind of a specific paragraph that is more broad than this?

A T-Route is a low altitude RNAV route. I believe they can be numbered
from 200-500 (e.g T200).

A Q-Route is a high altitude RNAV route.

So far as the restriction people have been stating having to do with not
being able to use the uncertified GPS units as a substitute for ADF/DME,
that stems from the AIM (1-2-3) (and possibly a change that has not been
published) restricting this type of usage to units that are compliant with
AC90-100.

--ron

Ron Rosenfeld wrote in
:

So far as the restriction people have been stating having to do with not
being able to use the uncertified GPS units as a substitute for ADF/DME,
that stems from the AIM (1-2-3) (and possibly a change that has not been
published) restricting this type of usage to units that are compliant
with AC90-100.

Ahh... Now I get why I didn't see it.

But the AIM is not regulatory, is it?

If it is, it's a stupid rule. One of the ILSs at my home airport actually
requires an ADF. What a pain.

"Danny Deger" wrote in message
...

"john smith" wrote in message
...
AvWeb has an article in todays issue saying that only the GPS 400/500
series and G1000 are the only IFR certified navigators that are legal to
use.

Does anyone know the rationale for why the GPS receivers can not longer be
used as ADF or DME subs? Or is there any rationale stated by the FAA?

Danny Deger
Certainly the case in parts of Europe especially the UK.

On Sat, 26 May 2007 19:48:19 GMT, Judah wrote:

Ron Rosenfeld wrote in
:

So far as the restriction people have been stating having to do with not
being able to use the uncertified GPS units as a substitute for ADF/DME,
that stems from the AIM (1-2-3) (and possibly a change that has not been
published) restricting this type of usage to units that are compliant
with AC90-100.

Ahh... Now I get why I didn't see it.

But the AIM is not regulatory, is it?

If it is, it's a stupid rule. One of the ILSs at my home airport actually
requires an ADF. What a pain.

Yeah, but there isn't any regulation allowing substitution of GPS for other
NAVAID's.

I think the AIM revision was just published today on the FAA web site. I
find it pretty confusing in terms of which units are allowed to do what.
--ron