Do I need DME or ADF in an IFR-certified GPS panel?

George Patterson wrote:
It's my understanding that the DME box in the plane measures distance from a
VOR. All VORs should be in the database.

Not all DME ground stations are co-located with VORs. Many are on
airports as part of an ILS-DME (and the exact location of the ground
station is not charted in that case).

If you look hard enough, you can find the occasional NDB-DME station.
I'm not aware of any stand-alone DME ground stations, but I can't
think of any reason why such a thing couldn't exist.

Roy Smith wrote:

If you look hard enough, you can find the occasional NDB-DME station.
I'm not aware of any stand-alone DME ground stations, but I can't
think of any reason why such a thing couldn't exist.

There are probably some TACAN only stations around somewhere, but I'm
not sure any civil procedures would use them.

Doug wrote:

There is, in fact, a requirement to be able to fly the approach at your
alternate without the use of GPS. So having DME will assist you in
finding legal alternates that have VOR/DME approaches. This will allow
you to carry less fuel and more payload. Without DME or ADF, all you
can fly is a VOR approach, and if you have radar, an ILS or LOC (maybe
a few obscure others). Even then some ILS's require DME or ADF.

My home airport has an ILS approach with ADF required, but I just
figured I could use the GPS to substitute for the ADF. From what I
understand of the above, that's true but that also means my airport's
ILS approach is not a legal alternate for someone planning a GPS
somewhere else, do I understand that right? (I'm an instrument
student, still learning this stuff and have found this thread fascinating).

I would say yes. Its very expensive to keep your IFR GPS IFR legal
(with updates). You may not keep it up to date year around, it would be
nice to have IFR equip in your plane that doesn't expire every 56 days.

Matt,

One I do fairly often is SDA GPS 12, which is a VOR/DME overlay.
Another is Laramie (WY) Rwy 30.


And those don't allow you to substitute the DME?

--
Thomas Borchert (EDDH)

xyzzy wrote:

My home airport has an ILS approach with ADF required, but I just
figured I could use the GPS to substitute for the ADF. From what I
understand of the above, that's true but that also means my airport's
ILS approach is not a legal alternate for someone planning a GPS
somewhere else, do I understand that right?

Yes.

On Tue, 07 Jun 2005 22:20:12 -0500, No Spam wrote:

I see there's a phone number tied to your AWOS - have you tried calling it
airborne with a cell phone?

I was not aware of a phone number; and I just checked the database at
AIRNAV and don't see one listed there or at AOPA. What is it? Where did
you find it? I'll give it a call and see what answers.




Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

On Tue, 7 Jun 2005 20:40:10 -0700, "Matt Barrow"
wrote:


"Ron Rosenfeld" wrote in message
.. .

Without an ADF receiver, I would not be able to obtain the local altimeter
setting at my home airport, and take advantage of lower minimums available
with that information.

Not on 124.675?




No, the NDB transmits on 260.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

On Wed, 08 Jun 2005 09:58:14 -0400, Ron Natalie wrote:

Jon Kraus wrote:
KUMP in Indianapolis transmits AWOS over their NDB on channel 338.


And neither FSS or Approach can get it for you?




So far as EPM is concerned, the information is only available on the NDB
frequency of 260. Neither Center nor FSS have access to it.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

On 8 Jun 2005 08:11:56 -0700, "Doug" wrote:

There is, in fact, a requirement to be able to fly the approach at your
alternate without the use of GPS.

That is not a requirement for TSO-C146a boxes, such as the GNS480.




Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)