GPS Question

On Sun, 12 Mar 2006 03:21:06 GMT, "Steven P. McNicoll"
wrote:


"Peter Clark" wrote in message
.. .

OK. I believe the answer is the GS/localizer and VOR respectively.


Why did you choose VOR for the VOR/DME RWY 15 at MTN? Do you see VOR
serving the same role there as the localizer does for the ILS/DME RWY 2 at
DRO?

I chose it because it's the point where the rest of the required
information (distance to maintain from and radial crossing) is derived
from.

For the arc portion of the DRO approach, no - the DRO VOR serves the
same purpose for that approach until hitting the lead radial.

On Sun, 12 Mar 2006 19:19:10 +0000, Peter
wrote:

Sorry if this is a dumb question but a quick look at that Baltimore
approach looks like the DME arc is the sole lateral guidance
mechanism.

I can fly DME arcs fine but have done them only as earlier parts of
approaches.

How easy is it to fly a DME arc to the required degree of accuracy?

It's been a while (like 4 or 5 years) since I had to do one but found
then relatively easy. Just remember which way to turn and watch the
DME.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
There is no left/right indication anywhere; you are turning left/right
according to the digital DME readout.

I notice the MDH is quite generous on this one; perhaps that's the
reason...

"Peter Clark" wrote in message
...

I chose it because it's the point where the rest of the required
information (distance to maintain from and radial crossing) is derived
from.


The I-DRO localizer provides distance information?



For the arc portion of the DRO approach, no - the DRO VOR serves the
same purpose for that approach until hitting the lead radial.


What navaid provides lateral guidance on the final approach course at DRO?
What navaid provides lateral guidance on the final approach course at MTN?


Here's a link to an approach at Antigo, Wisconsin:

http://www.myairplane.com/databases/...s/06215N16.PDF

Can GPS substitute for ADF on this approach? Please explain your answer.

"rps" wrote in message
oups.com...

My answer, based on what I learned from this thread and by reading
elsewhere, is that you cannot substitute GPS for ADF on this approach
because:

1) The chart doesn't indicate an overlay approach, such as with the
nomenclature "NDB/GPS" in the title; and
2) the NDB is the "primary" signal source for the approach. (See the
relevant AIM sections.)


Right, GPS cannot substitute for ADF on this approach because ADF is the
principal instrument approach navigation source. For that same reason GPS
cannot substitute for DME on the VOR/DME or TACAN Z RWY 15 at MTN.

On Mon, 13 Mar 2006 22:54:03 GMT, "Steven P. McNicoll"
wrote:


"Peter Clark" wrote in message
.. .

I chose it because it's the point where the rest of the required
information (distance to maintain from and radial crossing) is derived
from.


The I-DRO localizer provides distance information?

Who knows, the arc is based off the VOR/DME transmitter. I believe I
corrected that oversight in a later response.

For the arc portion of the DRO approach, no - the DRO VOR serves the
same purpose for that approach until hitting the lead radial.


What navaid provides lateral guidance on the final approach course at DRO?
What navaid provides lateral guidance on the final approach course at MTN?

None. Distance is from the VOR/DME transmitters, or in the case of an
ILS/DME the I-whatever. For these approaches I'm substituting the
GPS distance readout instead of having an actual DME box and using the
VOR head to drive the CDI for cross radials. Flying a DME arc is
specifically listed as a permitted operation in the AIM
1-1-19(f)(1)(a)(2).

Here's a link to an approach at Antigo, Wisconsin:

http://www.myairplane.com/databases/...s/06215N16.PDF

Can GPS substitute for ADF on this approach? Please explain your answer.

No, because there's no GPS overlay.

Who knows, the arc is based off the VOR/DME transmitter.

VOR and DME are two separate transmitters, on two separate frequencies,
with two separate methods. The channels are coordinated, that's about
all they have in common (except location at a co-located VOR/DME)

Jose
--
Money: what you need when you run out of brains.
for Email, make the obvious change in the address.

On Tue, 14 Mar 2006 00:05:04 GMT, "Steven P. McNicoll"
wrote:


"rps" wrote in message
roups.com...

My answer, based on what I learned from this thread and by reading
elsewhere, is that you cannot substitute GPS for ADF on this approach
because:

1) The chart doesn't indicate an overlay approach, such as with the
nomenclature "NDB/GPS" in the title; and
2) the NDB is the "primary" signal source for the approach. (See the
relevant AIM sections.)


Right, GPS cannot substitute for ADF on this approach because ADF is the
principal instrument approach navigation source. For that same reason GPS
cannot substitute for DME on the VOR/DME or TACAN Z RWY 15 at MTN.

But if you can't substitute DME to fly an arc because it's the primary
source of navigation then why is "DME arc" specifically listed in AIM
1-1-19 (f)(1)(a)(2) and blah/DME with arcs used as the examples of
permissible substitution on the AOPA GPS substitution page? That's
the piece of the puzzle I'm missing here.

"Peter Clark" wrote in message
...

Who knows, the arc is based off the VOR/DME transmitter. I believe I
corrected that oversight in a later response.


Who knows? Everybody that understands the applicable publications.



None. Distance is from the VOR/DME transmitters, or in the case of an
ILS/DME the I-whatever. For these approaches I'm substituting the
GPS distance readout instead of having an actual DME box and using the
VOR head to drive the CDI for cross radials. Flying a DME arc is
specifically listed as a permitted operation in the AIM
1-1-19(f)(1)(a)(2).


Right. No navaid provides lateral guidance on the final approach course for
either of these IAPs. Why would lateral guidance be needed on an instrument
approach anyway?

It appears you were fibbin' when you said you weren't trying to be obtuse
here.



No, because there's no GPS overlay.


Right answer, wrong reason.

On 03/14/06 08:51, Peter wrote:
"Steven P. McNicoll" wrote:

Right, GPS cannot substitute for ADF on this approach because ADF is the
principal instrument approach navigation source. For that same reason GPS
cannot substitute for DME on the VOR/DME or TACAN Z RWY 15 at MTN.

I am from Europe, where US-style GPS substitution for various navaids
is not permitted. So this is of academic interest only.

(With one small exception I know of, Switzerland, where (as is not
uncommon in Europe) an ADF is required for all controlled airspace
unless one carries a BRNAV approved GPS.)

Anyway, this thread has left me well confused. I've done the FAA IR
(at a U.S. school not using GPS so GPS questions didn't come up) so I
recall that any navaid shown on the approach plate can be substituted
for the OM, and only radar or an NDB (a "compass locator") can subst
for the middle marker.

I also recall that if an alternate is required (the destination not
meeting the 1/2/3 rule)

.... or if the destination doesn't have an instrument approach

and the only approach available at the
alternate is a GPS one, that airport cannot be filed as an
alternate.... or something like that. This requirement (which I
probably wrote wrongly) is what puzzles me regarding Cirrus (for
example) not being fitted with an ADF and a DME - doesn't it curtail
the alternate options considerably?

Not at all. There are a lot of ILS, VOR, etc. approaches which do not
require DME or ADF. Note that you do not need an ADF to make use of
the OM and MM - a marker beacon receiver is just fine.


Getting back to the more general substitution regs: on the *primary*
destination, is it OK to substitute a GPS for any navaid provided the
navaid is not used to provide the lateral guidance?

There is a section in the AIM which covers this question exactly. It
is called "Use of GPS in lieu of ADF and DME".

In this case, we're not talking about GPS approaches, but approaches
like ILS, VOR, NDB, etc. In these cases, the GPS can be used as a
substitute for the ADF and/or DME (in specific cases, as detailed
by the AIM). However, you would not be able to substitute the VOR
on a VOR approach, etc. For that, you need to fly the VOR (GPS)
or GPS approach.


--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

Steven P. McNicoll wrote:

Here's a link to an approach at Antigo, Wisconsin:

WOW! My home town! :-) However, I learned to fly at Cheyenne, WY.

http://www.myairplane.com/databases/...s/06215N16.PDF

Can GPS substitute for ADF on this approach? Please explain your answer.

No. The ADF is the Primary navaid. To use the GPS for this
approach, the approach would be relabeled, using "GPS" in the
header.

--------------------------------------------------------------------

Now, please review with me my home airport... KFNL
http://www.myairplane.com/databases/...s/05677I33.PDF

Note in the lower left of the central graphic box, where it says
"ADF REQUIRED". In this case the GPS may be substituted for the
NDB, as this is an ILS approach and the NDB is not the primary
navaid.

Best regards,

Jer/ "Flight instruction and mountain flying are my vocations!"
--
Jer/ (Slash) Eberhard, Mountain Flying Aviation, LTD, Ft Collins, CO
CELL 970 231-6325 EMAIL jeratfrii.com http://users.frii.com/jer/
C-206 N9513G, CFII Airplane&Glider FAA-DEN Aviation Safety Counselor
CAP-CO Mission&Aircraft CheckPilot BM218 HAM N0FZD 240 Young Eagles!