GPS and DME

[nobody]

Does anyone know if it is legal to substitute distance and speed from an
approach certified GPS in place of a DME on a DME required approach?

Thanks,
Ed

[Jim Burns]

Yep. See rec.aviation.ifr, we've pretty much beat it to death. Also see
the AIM.
Jim

"nobody" > wrote in message
m...
> Does anyone know if it is legal to substitute distance and speed from an
> approach certified GPS in place of a DME on a DME required approach?
>
> Thanks,
> Ed
>
>

[Ron Rosenfeld]

On Mon, 14 Feb 2005 19:10:20 GMT, "nobody" > wrote:

>Does anyone know if it is legal to substitute distance and speed from an
>approach certified GPS in place of a DME on a DME required approach?

Probably. What is the approach in question?
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[nobody]

No specific approach. I want to upgrade my panel and debating spending less
on a new GPS so I can install DME too or spend a little more on a nicer GPS
and blow off the DME.

I read the threads on rec.aviation.ifr. There was truly a ton of info
there.

Ed

"Ron Rosenfeld" > wrote in message
...
> On Mon, 14 Feb 2005 19:10:20 GMT, "nobody" > wrote:
>
>>Does anyone know if it is legal to substitute distance and speed from an
>>approach certified GPS in place of a DME on a DME required approach?
>
> Probably. What is the approach in question?
> Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Denny]

The bottom line is simple... GPS is a legal substitute where the GPS
distance measurement matches the DME numbers... It is not legal where
the DME is offset from the VOR or airport center and the GPS database
does not correct for this... Increasingly, the DME location and/or the
GPS databases have been matched up so either the GPS or the DME gives
you the appropriate distance measurement, and offset DME's are now
definitely in the minority...

You can skip installing the DME and simply check your approach plates
to be sure you are legal (and out of the trees) when shooting a DME
approach with the GPS as your distance measuring equipment...
There is the occasional approach that I run into where the plate says
DME REQUIRED... If you are IMC then you will simply have to shoot a
different approach using your GPS... OTOH, if the fickle finger of
fate takes down your GPS (for whatever reason) you may be wishing you
had a DME on the panel... I have both GPS and DME on board and both are
in use as cross check when shooting approaches...

Denny

[Ron Rosenfeld]

On Tue, 15 Feb 2005 05:30:17 GMT, "nobody" > wrote:

>No specific approach. I want to upgrade my panel and debating spending less
>on a new GPS so I can install DME too or spend a little more on a nicer GPS
>and blow off the DME.

I recently installed a CNX80 (now GNS480) and got rid of my DME. I've not
run into any circumstances where I miss it.

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

[Jim Burns]

Glad you caught the threads in rai. I was in no way trying to blow you off
or dismiss your question, it was just very timely. Be sure to check out the
AIM also http://www.faa.gov/ATpubs/AIM/Chap1/aim0101.html#1-1-19 see
section (f).
Jim

"nobody" > wrote in message
om...
> No specific approach. I want to upgrade my panel and debating spending
less
> on a new GPS so I can install DME too or spend a little more on a nicer
GPS
> and blow off the DME.
>
> I read the threads on rec.aviation.ifr. There was truly a ton of info
> there.
>
> Ed
>
> "Ron Rosenfeld" > wrote in message
> ...
> > On Mon, 14 Feb 2005 19:10:20 GMT, "nobody" > wrote:
> >
> >>Does anyone know if it is legal to substitute distance and speed from an
> >>approach certified GPS in place of a DME on a DME required approach?
> >
> > Probably. What is the approach in question?
> > Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)
>
>

[Newps]

Denny wrote:
> The bottom line is simple... GPS is a legal substitute where the GPS
> distance measurement matches the DME numbers... It is not legal where
> the DME is offset from the VOR or airport center and the GPS database
> does not correct for this... Increasingly, the DME location and/or the
> GPS databases have been matched up so either the GPS or the DME gives
> you the appropriate distance measurement, and offset DME's are now
> definitely in the minority...

Not quite right. GPS can substitute for DME even when the DME source
isn't in the database. For example my terminal/enroute GPS does not
have the DME location for ILS's. One of the approaches here at BIL
requires DME. I simply make the OM the active waypoint.

>
> You can skip installing the DME and simply check your approach plates
> to be sure you are legal (and out of the trees) when shooting a DME
> approach with the GPS as your distance measuring equipment...
> There is the occasional approach that I run into where the plate says
> DME REQUIRED... If you are IMC then you will simply have to shoot a
> different approach using your GPS...

Wrong. If you can determine distance with your GPS then you are good to go.

[Denny]

Hmm, not to be difficult, but if you come to the attention of the FAA
after shooting an approach using a GPS where the plate says DME
REQUIRED and the FSDO gets involved, it will be very entertaining to
listen to you lecture the inspector that you can simply create your own
approaches... But, you fly your ship your way and I will fly mine and
we will both be happy...

Cheers ... Denny

[Newps]

Denny wrote:
> Hmm, not to be difficult, but if you come to the attention of the FAA
> after shooting an approach using a GPS where the plate says DME
> REQUIRED

I have DME. It's my terminal/enroute GPS. What seems to be the
problem? A plate that says "DME Required" doesn't actually mean you
need a DME box. Just like the plate that says "ADF Required" doesn't
mean you have to have an ADF, the GPS substitutes for both quite nicely.
Do you have a FSDO that says otherwise?


and the FSDO gets involved, it will be very entertaining to
> listen to you lecture the inspector that you can simply create your own
> approaches...

I'm not creating my own approaches. I'm simply following the published
plate. Nowhere does it say that an approach labeled "DME Required" must
be flown with an actual DME.

[Lakeview Bill]

Have you noticed any ILS approaches labeled "ILS receiver" required?



"Newps" > wrote in message
...
>
>
> Denny wrote:
> > Hmm, not to be difficult, but if you come to the attention of the FAA
> > after shooting an approach using a GPS where the plate says DME
> > REQUIRED
>
> I have DME. It's my terminal/enroute GPS. What seems to be the
> problem? A plate that says "DME Required" doesn't actually mean you
> need a DME box. Just like the plate that says "ADF Required" doesn't
> mean you have to have an ADF, the GPS substitutes for both quite nicely.
> Do you have a FSDO that says otherwise?
>
>
> and the FSDO gets involved, it will be very entertaining to
> > listen to you lecture the inspector that you can simply create your own
> > approaches...
>
> I'm not creating my own approaches. I'm simply following the published
> plate. Nowhere does it say that an approach labeled "DME Required" must
> be flown with an actual DME.

[[email protected]]

Newps:

Why use the OM as waypoint? The DME at BIL is at the VOR, isn't it??!!
Which approach are you referring to, the ILS 28R or VOR_DME 28R?

[Newps]

wrote:
> Newps:
>
> Why use the OM as waypoint? The DME at BIL is at the VOR, isn't it??!!

No, the ILS 28R DME is at the localizer shack. Since that is not in my
database I navigate from ZELAR. Inbound it doesn't matter as you are
following the localizer, it only serves as a cross check for glideslope
intercept. On the localizer only approach you can go lower as you cross
ZELAR and it determines your MAP.


> Which approach are you referring to, the ILS 28R or VOR_DME 28R?

On the VOR/DME approach I navigate to the VOR. It's really easy to fly
an arc with my GPS and crossing MUSTY inbound you descend to 3940 and
wait for 4.6 DME to show up.