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

No Spam wrote:

I think the 430/530/480 incorporate VOR/ILS, so the loss of the GPS
constellation shouldn't leave one "lost", should it? I realize I'd be
limited to enroute/terminal operations that only require VOR/ILS should the
GPS system take a hike.

Here's another thought about keeping your ADF.

There are a considerable number of GPS approaches that are overlays of NDB
approaches. Normally, you would use the improved percision of the GPS and
fly it that way. Now the 430/530 requires that your database be current
in order to legally fly an approach (at least with the AFMS that I have).
Now say you are out of town when your database expires and you need to do
such an approach. With the ADF you could legally do the approach and
"monitor" it with the GPS. No ADF and you would need to choose some other
approach in order to stay legal.


--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR

On Tue, 07 Jun 2005 20:20:34 -0500, No Spam wrote:

Looking for thoughts out there...

If I have an IFR-certified GPS (terminal, not just enroute), is there any
reason to keep a DME or ADF in the panel? (Other than being able to listen
to am radio or tracking "non-offical" navaids - e.g., am radio stations!)

I find the DME to be an excellent cross reference on both IFR airways
and approaches.

I would pull the ADF though. It's use is minimal, and with XM/Sirius
radio, who needs AM anyway?

From a resale standpoint the DME is going to offer a higher value than
the ADF.

All this assumes you are posting/flying from the States. I believe
other countries still require ADF either for IFR flight or for many of
the approaches.

-Nathan

On Tue, 07 Jun 2005 20:20:34 -0500, No Spam wrote:

Looking for thoughts out there...

If I have an IFR-certified GPS (terminal, not just enroute), is there any
reason to keep a DME or ADF in the panel? (Other than being able to listen
to am radio or tracking "non-offical" navaids - e.g., am radio stations!)

Depending on where you are the ADF might be useful. I bet the DME
would be more useful overall, though. Does the presence of an actual
ADF or DME open up any approaches you can use when filing alternates
that the GPS alone doesn't because of the anti-substitution rules?

KUMP in Indianapolis transmits AWOS over their NDB on channel 338.

Jon Kraus
'79 Mooney 201

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.

I have no idea how many other airports there are where the local altimeter
is available ONLY via the ADF, but that is the case at KEPM.


Yours is the first I've ever heard of where the altimeter was even AVAILABLE
over an NDB (not that I was listening...).

On 6/7/05 22:35, "Matt Barrow" wrote:


"No Spam" wrote in message
...
On 6/7/05 20:40, "Peter R." wrote:

No Spam wrote:

If I have an IFR-certified GPS (terminal, not just enroute), is there
any
reason to keep a DME or ADF in the panel? (Other than being able to
listen
to am radio or tracking "non-offical" navaids - e.g., am radio
stations!)

There is no legal reason to keep those devices.

However, if you have them, they will certainly aid in situational
awareness.

Thanks, Peter,

I hadn't considering legality, but thanks for that point.

I was assuming the Garmin 430/530/480 to be the GPS unit(s), so I wouldn't
think SA could be improved by keeping the DME or ADF.

The ADF is no big deal, but definitely keep the DME. My guess is that you'll
find more GPS approaches that require DME than require ADF.



Thanks, Matt,

I had no idea that any GPS approaches existed that required DME - guess that
would make them "GPS-DME" approaches. Can you name some?

- Don
We can't all be heroes. Some of us have to
stand on the curb and clap as they go by.
- Will Rogers

On 6/7/05 23:28, "Frank Stutzman" wrote:

No Spam wrote:

I think the 430/530/480 incorporate VOR/ILS, so the loss of the GPS
constellation shouldn't leave one "lost", should it? I realize I'd be
limited to enroute/terminal operations that only require VOR/ILS should the
GPS system take a hike.

Here's another thought about keeping your ADF.

There are a considerable number of GPS approaches that are overlays of NDB
approaches. Normally, you would use the improved percision of the GPS and
fly it that way. Now the 430/530 requires that your database be current
in order to legally fly an approach (at least with the AFMS that I have).
Now say you are out of town when your database expires and you need to do
such an approach. With the ADF you could legally do the approach and
"monitor" it with the GPS. No ADF and you would need to choose some other
approach in order to stay legal.


Good idea, Frank. Good reason to use the laptop update via USB from Jeppesen
- assuming you have a way to get your laptop online.

Which begs another question - how soon before a (28-day cycle?) database
expires is the next cycle available online from Jeppesen?

- Don
The hardest thing about flying is the ground.
- Charles Kingsford-Smith

No Spam wrote:
Looking for thoughts out there...

If I have an IFR-certified GPS (terminal, not just enroute), is there any
reason to keep a DME or ADF in the panel? (Other than being able to listen
to am radio or tracking "non-offical" navaids - e.g., am radio stations!)

I just installed a GNS480/MX20/SL30 combo. I kept my old DME for no
particularly good reason other than it was a fairly recent King one
and I had the panel space. It means if my 480 crumps I can still
fly a ILS/DME approach into Dulles.

As for non-official navaids, you can drop an GPS waypoint anywhere
in the world and the 480 will drive the autopilot right to it.

As for ball games, my MX20 receives XM Radio as a side effect of
getting the weather downloads.

Matt Barrow wrote:


The ADF is no big deal, but definitely keep the DME. My guess is that you'll
find more GPS approaches that require DME than require ADF.



What GPS approaches would EVER require DME?

The only thing a DME lets you do is fly a non-GPS approach if
it required it. This is only useful if you want to fly to
places using a GPS-based approach and your only available
alternate requires DME.

No Spam wrote:
, Matt,

I had no idea that any GPS approaches existed that required DME - guess that
would make them "GPS-DME" approaches. Can you name some?

There are none, the concept is silly. If you have a GPS approach, the
DME is spurious.

Frank Stutzman wrote:


There are a considerable number of GPS approaches that are overlays of NDB
approaches. Normally, you would use the improved percision of the GPS and
fly it that way. Now the 430/530 requires that your database be current
in order to legally fly an approach (at least with the AFMS that I have).

My 480 FMS only requires me to know the approach info is right.
Of course the real answer is if you're going to fly IFR, you're going
to have to keep your NAVDATA (charts, GPS databases, etc... up to date).