Is your IFR GPS still legal for use?

"Neil Gould" wrote in message
t...
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


The reason the FAA have done this is set out in the AC it is to harmonise
with ICAO.

"This criterion is consistent with the ICAO guidance material for the
implementation of area navigation (RNAV 1 and RNAV 2) operations. AC 90-100
became effective 7 January 2005. Since then, ICAO has continued to harmonize
area navigation (RNAV) performance criteria. AC 90-100A reflects these
harmonized ICAO performance-based navigation criteria as well as lessons
learned from the initial US RNAV implementation. "



US aircraft had real difficulty operating under IFR in Europe as AC90-96A
and JAA TGL -10 shows.

One of the reasons why Cirrus and the like have been having to fit ADF and
DME into their Europe bound aircraft.

US aircraft had real difficulty operating under IFR in Europe as AC90-96A
and JAA TGL -10 shows.

Is this due to the laws of physics or the laws of Europe?

Jose
--
There are two kinds of people in the world. Those that just want to
know what button to push, and those that want to know what happens when
they push the button.
for Email, make the obvious change in the address.

Ron Rosenfeld wrote in
:

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.

But if the AIM is not regulatory, why does it matter?

IIRC, the Regs only say that you must have the equipment necessary for the
specific navigation being used.

On Mon, 28 May 2007 02:54:04 GMT, Judah wrote:

Ron Rosenfeld wrote in
:

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.

But if the AIM is not regulatory, why does it matter?

IIRC, the Regs only say that you must have the equipment necessary for the
specific navigation being used.

The lack of regulatory power of the AIM is one of those arguments that goes
on from time to time. But I believe that, regardless of how we may want to
interpret things, the FAA would have a pretty good case, if they wanted to,
if you, for example, landed out of an approach requiring an ADF, and you
did not even have a functioning ADF on board, nor an FAA approved
equivalent.

If I were the FAA lawyer arguing, I would point out the following:

-------------------------
91.205

a) General. ... no person may operate a powered civil aircraft with a
standard category U.S. airworthiness certificate in any operation described
in paragraphs (b) through (f) of this section unless that aircraft contains
the instruments and equipment specified in those paragraphs (or
FAA-approved equivalents) for that type of operation, and those instruments
and items of equipment are in operable condition.

(d) Instrument flight rules. For IFR flight, the following instruments and
equipment are required:

(2) ... navigational equipment appropriate to the ground facilities to be
used.
------------------------------

It is the AIM that effectively gives the FAA-approved equivalent (specified
in para (a)) for the navigational equipment specified in para (d)(2). And
the AIM specifically requires, for GPS equivalents, that they be compliant
with the AC.

I'm sure someone will write that a GPS that has been specifically listed as
UNapproved for an approach related operation in the AIM can be used for it
because it is somehow "appropriate to the ground facility being used" and
the AIM is not regulatory. I would prefer to be on the other side of that
argument.

Hopefully, the AIM, and possibly the AC, will be changed to again indicated
that previously approved FAA-equivalents are continuing to be approved.
--ron

Ron Rosenfeld wrote in
:

The lack of regulatory power of the AIM is one of those arguments that
goes on from time to time. But I believe that, regardless of how we may
want to interpret things, the FAA would have a pretty good case, if they
wanted to, if you, for example, landed out of an approach requiring an
ADF, and you did not even have a functioning ADF on board, nor an FAA
approved equivalent.

My guess is that it won't actually come up until someone has an accident
surrounding an NDB approach...

If I were the FAA lawyer arguing, I would point out the following:

-------------------------
91.205

a) General. ... no person may operate a powered civil aircraft with a
standard category U.S. airworthiness certificate in any operation
described in paragraphs (b) through (f) of this section unless that
aircraft contains the instruments and equipment specified in those
paragraphs (or FAA-approved equivalents) for that type of operation, and
those instruments and items of equipment are in operable condition.

(d) Instrument flight rules. For IFR flight, the following instruments
and
equipment are required:

(2) ... navigational equipment appropriate to the ground facilities to
be
used.
------------------------------

It is the AIM that effectively gives the FAA-approved equivalent
(specified in para (a)) for the navigational equipment specified in para
(d)(2). And the AIM specifically requires, for GPS equivalents, that
they be compliant with the AC.

And since I'm not a lawyer, I would probably respond that paragraph 1-2-3
(b)(2) specifically permits GPS units that are not fully compliant with AC
90-100, although it defines certain restrictions. However, AC 90-100
compliance is not required for equipment to be represented as "appropriate
to the ground facilities being used."

I'm sure someone will write that a GPS that has been specifically listed
as UNapproved for an approach related operation in the AIM can be used
for it because it is somehow "appropriate to the ground facility being
used" and the AIM is not regulatory. I would prefer to be on the other
side of that argument.

Compliance with AC 90-100 is only required for use "on segments of an
instrument approach, departure, or arrival procedure defined by a VOR
course" except those "which may be selected by route name or constructed by
'stringing' together two or more waypoints from an onboard navigation
database". Therefore these GPSes are not specifically UNapproved except for
a certain very specific type of operation. To say that this restriction
disqualifies the GPS from use for NDB approaches, for example, is non-
sequiter.

Hopefully, the AIM, and possibly the AC, will be changed to again
indicated that previously approved FAA-equivalents are continuing to be
approved. --ron

Yes, hopefully this whole mess will be cleared up quickly so that if
nothing else we can all go back to using our GPS without fear of being
ramp-checked.

On May 25, 4:43 pm, "Mark T. Dame" wrote:
B A R R Y wrote:

Roy Smith wrote:

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.

I always wondered the same thing.

You'd think a 196 on the yoke would outperform the ADF is some situations.

I can't think of a single situation where it wouldn't, under normal
operating conditions.


I can.

The 196 cannot pick up AM broadcast radio stations and play them thru
your audio panel.

Filling in for Bertie wrote in
:

MX****FORBRAINS WROTE:

What ever happened to checks and balances?

First, you balance your account, second, you write the check to the
electric company. Looks like you ****ed up that one earlier this
month, giving us a nice little break from your drivel.

Thanks d00d I needed the rest.


Bertie