Can a failed Glide Slope also void the Localizer approach?

[Jim Carter[_1_]]

I had a question today that I've never considered, and need the
experience of the group.



Are there airports with ILS approaches such that if the Glide Slope
component failed or went OTS, the entire approach would be un-executable
by regulation? I've always assumed that with the GS OTS I'd just revert
to the LOC, but are there approaches were the full ILS is approved but
the LOC only isn't? In other words, are there precision approaches where
vertical guidance is required and there is no non-precision alternative?

[150flivver]

Jim Carter wrote:

> Are there airports with ILS approaches such that if the Glide Slope
> component failed or went OTS, the entire approach would be un-executable
> by regulation? I've always assumed that with the GS OTS I'd just revert
> to the LOC, but are there approaches were the full ILS is approved but
> the LOC only isn't? In other words, are there precision approaches where
> vertical guidance is required and there is no non-precision alternative?
>
I would think if there are localizer minimums published, you could
revert to the localizer should the GS go out.

[Dave S]

Jim Carter wrote:
> I had a question today that I’ve never considered, and need the
> experience of the group.
>
>
>
> Are there airports with ILS approaches such that if the Glide Slope
> component failed or went OTS, the entire approach would be un-executable
> by regulation? I’ve always assumed that with the GS OTS I’d just revert
> to the LOC, but are there approaches were the full ILS is approved but
> the LOC only isn’t? In other words, are there precision approaches where
> vertical guidance is required and there is no non-precision alternative?
>
>
>

As another has stated: If there is a published localizer only approach,
or if the ILS approach has published localizer only minimums, then you
can proceed with a localizer approach.

If there are no localizer only approaches or minima charted, then I
would suspect you cannot do the approach under IFR.

Dave

[Jim Carter[_1_]]

> -----Original Message-----
> From: Dave S ]
> Posted At: Wednesday, August 23, 2006 5:18 AM
> Posted To: rec.aviation.ifr
> Conversation: Can a failed Glide Slope also void the Localizer
approach?
> Subject: Re: Can a failed Glide Slope also void the Localizer
approach?
>
> Jim Carter wrote:
> > I had a question today that I've never considered, and need the
> > experience of the group.
> >
> >
> >
> > Are there airports with ILS approaches such that if the Glide Slope
> > component failed or went OTS, the entire approach would be
un-executable
> > by regulation? I've always assumed that with the GS OTS I'd just
revert
> > to the LOC, but are there approaches were the full ILS is approved
but
> > the LOC only isn't? In other words, are there precision approaches
where
> > vertical guidance is required and there is no non-precision
alternative?
> >
> >
> >
>
> As another has stated: If there is a published localizer only
approach,
> or if the ILS approach has published localizer only minimums, then you
> can proceed with a localizer approach.
>
> If there are no localizer only approaches or minima charted, then I
> would suspect you cannot do the approach under IFR.
>
> Dave

I think we all understand the concept of Localizer only approach
minimums, but my question was "... are there approaches were the full
ILS is approved but the LOC only isn't?" Does anyone know of a specific
airport?

[Jim Carter[_1_]]

> -----Original Message-----
> From: Dave S ]
> Posted At: Wednesday, August 23, 2006 5:18 AM
> Posted To: rec.aviation.ifr
> Conversation: Can a failed Glide Slope also void the Localizer
approach?
> Subject: Re: Can a failed Glide Slope also void the Localizer
approach?
>
> Jim Carter wrote:
> > I had a question today that I've never considered, and need the
> > experience of the group.
> >
> >
> >
> > Are there airports with ILS approaches such that if the Glide Slope
> > component failed or went OTS, the entire approach would be
un-executable
> > by regulation? I've always assumed that with the GS OTS I'd just
revert
> > to the LOC, but are there approaches were the full ILS is approved
but
> > the LOC only isn't? In other words, are there precision approaches
where
> > vertical guidance is required and there is no non-precision
alternative?
> >
> >
> >
>
> As another has stated: If there is a published localizer only
approach,
> or if the ILS approach has published localizer only minimums, then you
> can proceed with a localizer approach.
>
> If there are no localizer only approaches or minima charted, then I
> would suspect you cannot do the approach under IFR.
>
> Dave

I think we all understand the concept of Localizer only approach
minimums, but my question was "... are there approaches were the full
ILS is approved but the LOC only isn't?" Does anyone know of a specific
airport?

[Jim Carter[_1_]]

> -----Original Message-----
> From: Dave S ]
> Posted At: Wednesday, August 23, 2006 5:18 AM
> Posted To: rec.aviation.ifr
> Conversation: Can a failed Glide Slope also void the Localizer
approach?
> Subject: Re: Can a failed Glide Slope also void the Localizer
approach?
>
> Jim Carter wrote:
> > I had a question today that I've never considered, and need the
> > experience of the group.
> >
> >
> >
> > Are there airports with ILS approaches such that if the Glide Slope
> > component failed or went OTS, the entire approach would be
un-executable
> > by regulation? I've always assumed that with the GS OTS I'd just
revert
> > to the LOC, but are there approaches were the full ILS is approved
but
> > the LOC only isn't? In other words, are there precision approaches
where
> > vertical guidance is required and there is no non-precision
alternative?
> >
> >
> >
>
> As another has stated: If there is a published localizer only
approach,
> or if the ILS approach has published localizer only minimums, then you
> can proceed with a localizer approach.
>
> If there are no localizer only approaches or minima charted, then I
> would suspect you cannot do the approach under IFR.
>
> Dave

I think we all understand the concept of Localizer only approach
minimums, but my question was "... are there approaches were the full
ILS is approved but the LOC only isn't?" Does anyone know of a specific
airport?

[Jim Macklin]

I have not looked at every ILS to see the answer, but I
would guess that some standard or special [private] ILS
procedure at an airport with many obstructions or in the
mountains could require a GS and not be allowed otherwise.
To get the answer you need to reread the TERPS manual or
perhaps call Flight Standards in OKC and ask the experts.
At the pilot end, fly what is authorized on the chart and by
NOTAM.


"Jim Carter" > wrote in message
news:00a401c6c6af$7009ba60$4001a8c0@omnibook6100.. .
|
|
| > -----Original Message-----
| > From: Dave S ]
| > Posted At: Wednesday, August 23, 2006 5:18 AM
| > Posted To: rec.aviation.ifr
| > Conversation: Can a failed Glide Slope also void the
Localizer
| approach?
| > Subject: Re: Can a failed Glide Slope also void the
Localizer
| approach?
| >
| > Jim Carter wrote:
| > > I had a question today that I've never considered, and
need the
| > > experience of the group.
| > >
| > >
| > >
| > > Are there airports with ILS approaches such that if
the Glide Slope
| > > component failed or went OTS, the entire approach
would be
| un-executable
| > > by regulation? I've always assumed that with the GS
OTS I'd just
| revert
| > > to the LOC, but are there approaches were the full ILS
is approved
| but
| > > the LOC only isn't? In other words, are there
precision approaches
| where
| > > vertical guidance is required and there is no
non-precision
| alternative?
| > >
| > >
| > >
| >
| > As another has stated: If there is a published localizer
only
| approach,
| > or if the ILS approach has published localizer only
minimums, then you
| > can proceed with a localizer approach.
| >
| > If there are no localizer only approaches or minima
charted, then I
| > would suspect you cannot do the approach under IFR.
| >
| > Dave
|
| I think we all understand the concept of Localizer only
approach
| minimums, but my question was "... are there approaches
were the full
| ILS is approved but the LOC only isn't?" Does anyone know
of a specific
| airport?
|
|

[Sam Spade]

Jim Carter wrote:

> I had a question today that I’ve never considered, and need the
> experience of the group.
>
>
>
> Are there airports with ILS approaches such that if the Glide Slope
> component failed or went OTS, the entire approach would be un-executable
> by regulation? I’ve always assumed that with the GS OTS I’d just revert
> to the LOC, but are there approaches were the full ILS is approved but
> the LOC only isn’t? In other words, are there precision approaches where
> vertical guidance is required and there is no non-precision alternative?
>
>
>
Quite a few, such as Boeing Field, Arcata,California Reno, Butte,
Montana. All of those have a separate LOC procedure, which cannot be
switched to midsstream. Missula, Montana was an ILS that does not have
a separate LOC IAP.

It's all about being able to place stepdown fixes in accordance with
TERPs criteria (facility accuracy, fix displacement factor) rather than
with the continous, and varying with distance, electronic glide-path
obstacle clearance plane.

[JPH]

Jim Carter wrote:
> I had a question today that I’ve never considered, and need the
> experience of the group.
>
>
>
> Are there airports with ILS approaches such that if the Glide Slope
> component failed or went OTS, the entire approach would be un-executable
> by regulation? I’ve always assumed that with the GS OTS I’d just revert
> to the LOC, but are there approaches were the full ILS is approved but
> the LOC only isn’t? In other words, are there precision approaches where
> vertical guidance is required and there is no non-precision alternative?
>
>
>
There are some procedures that only have precision ILS minima published
on the procedure, so if the GS went OTS, then that procedure would not
be available simply because that procedure requires the glideslope and
has no LOC line of minima. If they have circling minima on the ILS then
there is a note "Circling requires descent on glideslope to MDA".
See the example at Butte, Montana;
http://www.naco.faa.gov/d-tpp/0608/00588I15.PDF
In that example, there is no non-precision alternative on that
particular plate, but there is a LOC procedure published on a separate
approach plate if you want to fly the LOC only procedure.
I don't know offhand if there are any ILS runways that have no "LOC
only" mins available at all.

JPH

[Sam Spade]

JPH wrote:

> I don't know offhand if there are any ILS runways that have no "LOC
> only" mins available at all.
>
> JPH

KMSO

[Jim Carter[_1_]]

Thanks a lot Sam. This is what I needed; a few specific sites that I can
use for reference.

> -----Original Message-----
> From: Sam Spade ]
> Posted At: Wednesday, August 23, 2006 10:32 AM
> Posted To: rec.aviation.ifr
> Conversation: Can a failed Glide Slope also void the Localizer
approach?
> Subject: Re: Can a failed Glide Slope also void the Localizer
approach?
>
....
> Quite a few, such as Boeing Field, Arcata, California Reno, Butte,
> Montana. All of those have a separate LOC procedure, which cannot be
> switched to midsstream. Missula, Montana was an ILS that does not
have
> a separate LOC IAP.
>

[Jose[_1_]]

> All of those have a separate LOC procedure, which cannot be switched to midsstream.

Why could one not switch midstream? Assuming the LOC course is the
same, if the GS goes out, fly level until the next stepdown.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[Ron Rosenfeld]

On Thu, 24 Aug 2006 04:20:06 GMT, Jose > wrote:

>> All of those have a separate LOC procedure, which cannot be switched to midsstream.
>
>Why could one not switch midstream? Assuming the LOC course is the
>same, if the GS goes out, fly level until the next stepdown.
>
>Jose

That's not a bad question. But easily answered if you look at the charts. I
didn't look at all of them, but perhaps if you examined the BFI ILS Rwy 13R
approach, or the KMSO ILS RWY 11 approach, you would understand.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Andrew Sarangan[_1_]]

Jose wrote:
> > All of those have a separate LOC procedure, which cannot be switched to midsstream.
>
> Why could one not switch midstream? Assuming the LOC course is the
> same, if the GS goes out, fly level until the next stepdown.
>
> Jose


It is fine to switch mid stream. Looking at the BTM approach, I suspect
the only reason the LOC and ILS are published as separate charts is
because several significant differences in IAF, glideslope intercept
altitude and Missed Procedures. The chart would be way too cluttered if
presented on one sheet.

[Jose[_1_]]

> but perhaps if you examined the BFI ILS Rwy 13R
> approach, or the KMSO ILS RWY 11 approach, you would understand.

Well, maybe I'm thick, but I don't understand. True, you need to be
prepared to switch (i.e. have the chart handy, have the DME tuned
properly) but I see no reason why a properly prepared pilot could not
switch. True, you may be below the stepdown fix when you lose the GS,
but if you don't go any lower, you won't hit anything (the GS has
already provided obstacle clearance) and you should be able to fly your
present altitude until the next stepdown.

Or... set up for the LOC, but fly the GS if it's available.

I'm looking right now at the BFI ILS 13R and the LOC/DME for the same
runway.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[Michael[_1_]]

Jose wrote:
> Well, maybe I'm thick, but I don't understand. True, you need to be
> prepared to switch (i.e. have the chart handy, have the DME tuned
> properly) but I see no reason why a properly prepared pilot could not
> switch.
> Or... set up for the LOC, but fly the GS if it's available.
> I'm looking right now at the BFI ILS 13R and the LOC/DME for the same
> runway.

Try looking at the BTM ILS 15 and LOC/DME for the same runway, and it
will be a lot clearer. You can't set up for the LOC and use GS if
available, because the procedures for setting up are not the same. On
the ILS, you intercept the GS at 10,600, at 14+ DME from I-BEY. On the
LOC/DME, you can be down to 9600 at that point. Even if you do pull
that off (and it can certainly be done - at least the intercept is from
below), there is another reason you can't do it. The missed approach
for the ILS has you climbing to 11,000. On the LOC/DME, it's only
9,200. Might be iffy if the controller has someone holding at CPN at
11,000 or something similar.

There certainly are situations (BFI ILS 13 and LOC/DME comes to mind)
where the approaches are sufficiently similar that you could do it
safely, but that's not how the regulations work. If you are cleared
for one approach, you can't just change your mind and do another,
because there is no requirement to design them such that the change is
safe - and BTM is one example where the change is NOT safe. Therefore,
you are cleared for one given approach (unless given a cruise clearance
or explicitly cleared for any approach) and you must obtain an amended
clearance if you want to change your mind.

In those situations where the approaches are on the same plate (say
ILS/LOC or VOR/GPS or some such) the approach clearance covers whatever
is on the plate for which you have the equipment, and thus you can make
the change midstream if you so choose since the design of the approach
is such that the change is safe.

Michael

[Sam Spade]

Jose wrote:
>> All of those have a separate LOC procedure, which cannot be switched
>> to midsstream.
>
>
> Why could one not switch midstream? Assuming the LOC course is the
> same, if the GS goes out, fly level until the next stepdown.
>
> Jose

They are on separate charts with separate titles because they are
sufficiently different to defy making a clear chart.

[Ron Rosenfeld]

On Thu, 24 Aug 2006 15:01:06 GMT, Jose > wrote:

>> but perhaps if you examined the BFI ILS Rwy 13R
>> approach, or the KMSO ILS RWY 11 approach, you would understand.
>
>Well, maybe I'm thick, but I don't understand. True, you need to be
>prepared to switch (i.e. have the chart handy, have the DME tuned
>properly) but I see no reason why a properly prepared pilot could not
>switch. True, you may be below the stepdown fix when you lose the GS,
>but if you don't go any lower, you won't hit anything (the GS has
>already provided obstacle clearance) and you should be able to fly your
>present altitude until the next stepdown.
>
>Or... set up for the LOC, but fly the GS if it's available.
>
>I'm looking right now at the BFI ILS 13R and the LOC/DME for the same
>runway.
>
>Jose


What Michael wrote.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)