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View Full Version : DME req'd on ILS (not ILS-DME) approach?


Don Faulkner
October 2nd 03, 04:47 PM
Hi folks. I've got a bit of a puzzle here.
First off, I'm a student pilot, so maybe I haven't gotten to this yet.

Take a look at the ILS 18 plate for Springdale, AR (ASG):
http://myairplane.com/databases/approach/SouthCentral/ASG_ir18.pdf

First, note that the approach is "ILS RWY 18"
---
Next, read in the notes section:
Circling NA east of Rwy 18-36, inoperative table does not apply.
DME from RZC VORTAC
Simultaneous reception of I-ASG and RZC DME required.
---

So, the way I read this, DME is not required, since the approach is ILS
not ILS DME, but it is required since "simultaneous reception ... is
required."

I guess my real question is, "Is this approach authorized for an aircraft
without DME? And if not, why don't they call it ILS-DME?" but read on for
my thinking...

Looking at the chart, here are the uses of DME that I see:
1. DME arcs to intercept the localizer
2. A 3.8 DME non-precision MAP (my Jepp plate shows a non-precision decent
with DME 3.8 as the MAP)
3. WESTY intersection, 18 DME out, which can also be identified by a
cross-radial from the DAK VOR.

Now, this is how I reason (i.e. rationalize. :) my way out of these:
1. I tune the RZC VORTAC and fly the DME ARC, but once I turn to intercept
the localizer, I no longer care about the ARC, so I don't need DME anymore.
2. DME would be helpful here, and simultaneous reception would be
required, but I could also time from the FAF to identify the MAP.
3. I can swap VOR receivers once safely established on missed approach, so
I shouldn't need this for the inbound part of the approach.

To my thinking, #2 is the shakiest logic. Still, if DME is required, why
don't they just call it an ILS-DME approach?
--
Don Faulkner, KB5WPM |
(This space | "All that is gold does not glitter."
unintentionally | "Not all those who wander are lost."
left blank) | -- J.R.R. Tolkien

Steven P. McNicoll
October 2nd 03, 05:39 PM
"Don Faulkner" > wrote in message
...
>
> Hi folks. I've got a bit of a puzzle here.
> First off, I'm a student pilot, so maybe I haven't gotten to this yet.
>
> Take a look at the ILS 18 plate for Springdale, AR (ASG):
> http://myairplane.com/databases/approach/SouthCentral/ASG_ir18.pdf
>
> First, note that the approach is "ILS RWY 18"
> ---
> Next, read in the notes section:
> Circling NA east of Rwy 18-36, inoperative table does not apply.
> DME from RZC VORTAC
> Simultaneous reception of I-ASG and RZC DME required.
> ---
>
> So, the way I read this, DME is not required, since the approach is ILS
> not ILS DME, but it is required since "simultaneous reception ... is
> required."
>
> I guess my real question is, "Is this approach authorized for an aircraft
> without DME? And if not, why don't they call it ILS-DME?" but read on for
> my thinking...
>
> Looking at the chart, here are the uses of DME that I see:
> 1. DME arcs to intercept the localizer
> 2. A 3.8 DME non-precision MAP (my Jepp plate shows a non-precision decent
> with DME 3.8 as the MAP)
> 3. WESTY intersection, 18 DME out, which can also be identified by a
> cross-radial from the DAK VOR.
>
> Now, this is how I reason (i.e. rationalize. :) my way out of these:
> 1. I tune the RZC VORTAC and fly the DME ARC, but once I turn to intercept
> the localizer, I no longer care about the ARC, so I don't need DME
anymore.
> 2. DME would be helpful here, and simultaneous reception would be
> required, but I could also time from the FAF to identify the MAP.
> 3. I can swap VOR receivers once safely established on missed approach, so
> I shouldn't need this for the inbound part of the approach.
>
> To my thinking, #2 is the shakiest logic. Still, if DME is required, why
> don't they just call it an ILS-DME approach?
>

Looks to me like the only portion of this approach that requires DME is the
8 DME arc to the localizer. If you're going to fly this procedure you must
be able to receive the localizer and DME from RZC VORTAC simultaneously. To
fly it without simultaneous reception would require you to tune and identify
the localizer upon reaching one of the lead radials. Not an impossible
task, but one that can be rather distracting and possibly vertigo-inducing.
I have an old chart book with a previous version of this approach, Amdt 6A,
that does not have this simultaneous reception requirement. It appears
somebody thought it was a good thing to add.

There are a couple of curious things about this approach. What is the
purpose of TINSE and how does one identify it? I looked up TINSE in the
Location Identifiers book, it's 8 DME from RZC on the localizer, but you
couldn't tell that from the plate. What is the purpose of "2800 NoPT (7.5)"
just inside of the arc? I see only three ways to get to that point once
inbound on the localizer; via the arc which is already designated NoPT, via
radar vectors which by regulation prohibit a PT, or after already having
completed a PT.

Ron Natalie
October 2nd 03, 05:43 PM
"Steven P. McNicoll" > wrote in message link.net...

> There are a couple of curious things about this approach. What is the
> purpose of TINSE and how does one identify it?

It's certainly odd, isn't it. I thought it was some "vectors to final" crutch
to appease the GPS crowd.

October 2nd 03, 06:54 PM
DME is not required to fly this procedure unless you elect to fly the ARC
initial approach segments. In that case, you have to be able to receive the
DME from the VOR at the same time you are receiving the LOC. It is a
boilerplate note they put on anytime the DME is not frequency-paired with the
ILS.

But, you're right, you could easily fly the ARC, then use the lead radials to
change to the LOC. The note serves no real purpose on this IAP.

Don Faulkner wrote:

> Hi folks. I've got a bit of a puzzle here.
> First off, I'm a student pilot, so maybe I haven't gotten to this yet.
>
> Take a look at the ILS 18 plate for Springdale, AR (ASG):
> http://myairplane.com/databases/approach/SouthCentral/ASG_ir18.pdf
>
> First, note that the approach is "ILS RWY 18"
> ---
> Next, read in the notes section:
> Circling NA east of Rwy 18-36, inoperative table does not apply.
> DME from RZC VORTAC
> Simultaneous reception of I-ASG and RZC DME required.
> ---
>
> So, the way I read this, DME is not required, since the approach is ILS
> not ILS DME, but it is required since "simultaneous reception ... is
> required."
>
> I guess my real question is, "Is this approach authorized for an aircraft
> without DME? And if not, why don't they call it ILS-DME?" but read on for
> my thinking...
>
> Looking at the chart, here are the uses of DME that I see:
> 1. DME arcs to intercept the localizer
> 2. A 3.8 DME non-precision MAP (my Jepp plate shows a non-precision decent
> with DME 3.8 as the MAP)
> 3. WESTY intersection, 18 DME out, which can also be identified by a
> cross-radial from the DAK VOR.
>
> Now, this is how I reason (i.e. rationalize. :) my way out of these:
> 1. I tune the RZC VORTAC and fly the DME ARC, but once I turn to intercept
> the localizer, I no longer care about the ARC, so I don't need DME anymore.
> 2. DME would be helpful here, and simultaneous reception would be
> required, but I could also time from the FAF to identify the MAP.
> 3. I can swap VOR receivers once safely established on missed approach, so
> I shouldn't need this for the inbound part of the approach.
>
> To my thinking, #2 is the shakiest logic. Still, if DME is required, why
> don't they just call it an ILS-DME approach?
> --
> Don Faulkner, KB5WPM |
> (This space | "All that is gold does not glitter."
> unintentionally | "Not all those who wander are lost."
> left blank) | -- J.R.R. Tolkien

October 2nd 03, 06:59 PM
The following is the paragraph (807) out of FAA Handbook 8260.19C, "Flight
Procedures and Airspace" that resulted in that reception note even though it
makes no sense at this particular location:

3) DME frequencies are paired with the frequencies of the VOR, localizer, or
MLS. When a non-paired DME is used in a VOR/DME, ILS/DME, etc., procedure,
simultaneous reception of both facilities must be assured. This requires a
standard Note indicating the DME location and the identification of both
facilities: "DME from XYZ VORTAC. Simultaneous reception of I-ABC and XYZ DME
required:" DME frequencies are not paired with NDBs; and, DME antennas may or
may not be collocated with the NDB. For NDB/DME SIAPs, use standard Note:
"Simultaneous reception of ABC NDB and XYZ DME required."

Greg Esres
October 2nd 03, 07:34 PM
<<It is a boilerplate note they put on anytime the DME is not
frequency-paired with the ILS.>>

There are zillions of arcs to localizers that don't have this note.
The 8260.19C says they only apply to approaches with DME in the title.
I have an old plate for this approach, and it lacks the note.

<<But, you're right, you could easily fly the ARC, then use the lead
radials to change to the LOC. >>

That is precisely the purpose of the lead radials, is it not?

Ron Rosenfeld
October 2nd 03, 08:27 PM
On Thu, 02 Oct 2003 10:47:47 -0500, Don Faulkner >
wrote:

>Hi folks. I've got a bit of a puzzle here.
>First off, I'm a student pilot, so maybe I haven't gotten to this yet.
>
>Take a look at the ILS 18 plate for Springdale, AR (ASG):
>http://myairplane.com/databases/approach/SouthCentral/ASG_ir18.pdf
>
>First, note that the approach is "ILS RWY 18"
>---
>Next, read in the notes section:
>Circling NA east of Rwy 18-36, inoperative table does not apply.
>DME from RZC VORTAC
>Simultaneous reception of I-ASG and RZC DME required.
>---
>
>So, the way I read this, DME is not required, since the approach is ILS
>not ILS DME, but it is required since "simultaneous reception ... is
>required."
>
>I guess my real question is, "Is this approach authorized for an aircraft
>without DME? And if not, why don't they call it ILS-DME?" but read on for
>my thinking...
>

Under the approach naming conventions used by TERPS, DME only appears in
the approach name if it is required in order to fly the FINAL approach
segment. "ILS procedures do not require DME to fly the final approach, even
if a DME fix has been substituted for one of the marker beacons, therefore,
ILS procedures shall not be named ILS/DME. If a procedure requires DME to
fly the final approach, the suffix “DME” shall be added; ..."

And my interpretation of the note is that, indeed, DME is legally required
to fly the approach. It is used to ID two of the IAF's and could be used
to ID the MAP (for the LOC approach) and/or Westy (it's not necessary for
either one). And yes, you could fly the approach without DME by navigating
to NOBBY as the IAF; and using timing if you are using the LOC approach;
and using radials to ID WESTY.

I don't know the requirements for putting a DME required note in the
procedure, when it is possible to fly at least one of the charted
procedures without using DME.


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

Steven P. McNicoll
October 2nd 03, 08:30 PM
"Ron Rosenfeld" > wrote in message
...
>
> And my interpretation of the note is that, indeed, DME is legally required
> to fly the approach. It is used to ID two of the IAF's and could be used
> to ID the MAP (for the LOC approach) and/or Westy (it's not necessary for
> either one). And yes, you could fly the approach without DME by
navigating
> to NOBBY as the IAF; and using timing if you are using the LOC approach;
> and using radials to ID WESTY.
>
> I don't know the requirements for putting a DME required note in the
> procedure, when it is possible to fly at least one of the charted
> procedures without using DME.
>

You're saying this approach can be flown without DME yet you believe DME is
legally required to fly this approach?

Mike Granby
October 2nd 03, 10:07 PM
"Steven P. McNicoll" > wrote:

> You're saying this approach can be flown without DME yet
> you believe DME is legally required to fly this approach?

Is that so unusual? The ILS into CXY used to have ADF REQUIRED on the plate,
even though you could easily fly it without such equipment if receiving
radar vectors. (The plate now says ADF or RADAR, but was only changed
recently.)

--
Mike Granby, PP-ASEL,IA
Warrior N44578
http://www.mikeg.net/plane

October 3rd 03, 05:26 AM
Greg Esres wrote:

> <<It is a boilerplate note they put on anytime the DME is not
> frequency-paired with the ILS.>>
>
> There are zillions of arcs to localizers that don't have this note.
> The 8260.19C says they only apply to approaches with DME in the title.
> I have an old plate for this approach, and it lacks the note.

Guess that shows I am not much better than the person who designed the
latest amendment to this IAP, not to mention his/her supervisor and QC
staff. ;-)

>
>
> <<But, you're right, you could easily fly the ARC, then use the lead
> radials to change to the LOC. >>
>
> That is precisely the purpose of the lead radials, is it not?

I hesitate to say "precisely," but, yes, lead radials are for turn
anticpation.

Steven P. McNicoll
October 3rd 03, 06:08 AM
"Mike Granby" > wrote in message
...
>
> Is that so unusual? The ILS into CXY used to have ADF REQUIRED on the
plate,
> even though you could easily fly it without such equipment if receiving
> radar vectors. (The plate now says ADF or RADAR, but was only changed
> recently.)
>

This plate does not say "DME REQUIRED".

Ray Andraka
October 3rd 03, 03:20 PM
Please see my not in the SLE LOC BC RWY13 thread regarding DME on ILS's. FAA
has an initiative to standardiae ILS approaches that has the effect of making
many of the existing ILS approaches DME required where they were not before.
It happened to Providence this summer. We used to have 2 ILSs that did not
require DME and one that did. Now every approach into Providence with the
exception of the VOR 5, VOR 34 and NDB 5 approaches requires DME or IFR GPS.

"Steven P. McNicoll" wrote:

> "Mike Granby" > wrote in message
> ...
> >
> > Is that so unusual? The ILS into CXY used to have ADF REQUIRED on the
> plate,
> > even though you could easily fly it without such equipment if receiving
> > radar vectors. (The plate now says ADF or RADAR, but was only changed
> > recently.)
> >
>
> This plate does not say "DME REQUIRED".

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

Max T, CFI
October 7th 03, 01:10 AM
Usually if DME or other facility is required, it's in the title, or in a note that appears in VERY large BOLD text
and says something like "ADF or RADAR is required" in the plan view. Neither appears on this chart.
If you use NOBBY as the IAF, you'll have no need for DME, as it's not required for the LOC MAP (timing
works just as well) and it's not required for the missed approach procedure.

My read is "if you use DME," you must receive the localizer simultaneously. It's possible that's so you positively
identify the localizer, and don't start to fly inbound too soon on a false sidelobe from the localizer antenna. Which
could
ruin your day.
Max T, MCFI

Don Faulkner > wrote in message ...
> Hi folks. I've got a bit of a puzzle here.
> First off, I'm a student pilot, so maybe I haven't gotten to this yet.
>
> Take a look at the ILS 18 plate for Springdale, AR (ASG):
> http://myairplane.com/databases/approach/SouthCentral/ASG_ir18.pdf
>
> First, note that the approach is "ILS RWY 18"
> ---
> Next, read in the notes section:
> Circling NA east of Rwy 18-36, inoperative table does not apply.
> DME from RZC VORTAC
> Simultaneous reception of I-ASG and RZC DME required.
> ---
>
> So, the way I read this, DME is not required, since the approach is ILS
> not ILS DME, but it is required since "simultaneous reception ... is
> required."
>
> I guess my real question is, "Is this approach authorized for an aircraft
> without DME? And if not, why don't they call it ILS-DME?" but read on for
> my thinking...

Tim J
October 7th 03, 03:54 AM
I agree - and to clarify, the original poster's quotation of the notes
section lacks the proper punctuation. All of those comments are independent
of each other.

There are DME arcs - if you use DME (and that is DME from VOR, not the
localizer) then you must also be able to receive the localizer as well.

As Max T pointed out, you can fly the approach without DME.


"Max T, CFI" > wrote in message
news:Yvngb.700718$uu5.114905@sccrnsc04...
> Usually if DME or other facility is required, it's in the title, or in a
note that appears in VERY large BOLD text
> and says something like "ADF or RADAR is required" in the plan view.
Neither appears on this chart.
> If you use NOBBY as the IAF, you'll have no need for DME, as it's not
required for the LOC MAP (timing
> works just as well) and it's not required for the missed approach
procedure.
>
> My read is "if you use DME," you must receive the localizer
simultaneously. It's possible that's so you positively
> identify the localizer, and don't start to fly inbound too soon on a false
sidelobe from the localizer antenna. Which
> could
> ruin your day.
> Max T, MCFI
>
> Don Faulkner > wrote in message
...
> > Hi folks. I've got a bit of a puzzle here.
> > First off, I'm a student pilot, so maybe I haven't gotten to this yet.
> >
> > Take a look at the ILS 18 plate for Springdale, AR (ASG):
> > http://myairplane.com/databases/approach/SouthCentral/ASG_ir18.pdf
> >
> > First, note that the approach is "ILS RWY 18"
> > ---
> > Next, read in the notes section:
> > Circling NA east of Rwy 18-36, inoperative table does not apply.
> > DME from RZC VORTAC
> > Simultaneous reception of I-ASG and RZC DME required.
> > ---
> >
> > So, the way I read this, DME is not required, since the approach is ILS
> > not ILS DME, but it is required since "simultaneous reception ... is
> > required."
> >
> > I guess my real question is, "Is this approach authorized for an
aircraft
> > without DME? And if not, why don't they call it ILS-DME?" but read on
for
> > my thinking...
>
>
>

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