Outer Marker

When doing an ILS approach, with the glideslope, is it a requirement to be
able to identify the outer marker or a substitute? FAR 91.175(k) lists the
outer marker as one of the "basic ground components" and gives the acceptable
substitutes, but doesn't explicitly say that it's required. The AIM 1-1-9(j)
on "Inoperative Components" mentions the localizer and glideslope, but says
nothing about the outer marker.

If you answer, please give a specific FAA reference that says whether or not
the OM or a substitute is required.

Thanks.

Barry

In a previous article, "Barry" said:
When doing an ILS approach, with the glideslope, is it a requirement to be
able to identify the outer marker or a substitute? FAR 91.175(k) lists the

"or a substitute" is the operative phrase. If the FAF is identified by an
intersection, LOM, or DME, that's an acceptable substitute for a locator
beacon.


--
Paul Tomblin http://xcski.com/blogs/pt/
"It is a universal truth that the loss of liberty will be charged to
dangers, real or imagined, from abroad." - James Madison

On Thu, 22 Jan 2004 14:31:34 +0000 (UTC), (Paul
Tomblin) wrote:

In a previous article, "Barry" said:
When doing an ILS approach, with the glideslope, is it a requirement to be
able to identify the outer marker or a substitute? FAR 91.175(k) lists the

"or a substitute" is the operative phrase. If the FAF is identified by an
intersection, LOM, or DME, that's an acceptable substitute for a locator
beacon.

In my experience, it has been most unusual for an OM to be located at the
FAF for an ILS approach. They try to get them close, but they rarely are
(at least here in the NorthEast).


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

"Ron Rosenfeld" wrote in message
...
On Thu, 22 Jan 2004 14:31:34 +0000 (UTC), (Paul
Tomblin) wrote:

In a previous article, "Barry" said:
When doing an ILS approach, with the glideslope, is it a requirement to
be
able to identify the outer marker or a substitute? FAR 91.175(k) lists
the

"or a substitute" is the operative phrase. If the FAF is identified by
an
intersection, LOM, or DME, that's an acceptable substitute for a locator
beacon.

In my experience, it has been most unusual for an OM to be located at the
FAF for an ILS approach. They try to get them close, but they rarely are
(at least here in the NorthEast).

I wondered about that. It *is* at the marker at my home field (PAE), thanks
to a remarkably well-located spit of land north of the bay, and I made the
appropriate mistake on my oral. After a snack break, I looked it up and came
back to the examiner with the right answer (GS intercept).

-- David Brooks

Paul Tomblin wrote:
In a previous article, Barry said:
When doing an ILS approach, with the glideslope, is it a requirement to
be
able to identify the outer marker or a substitute? FAR 91.175(k) lists
the

"or a substitute" is the operative phrase. If the FAF is identified by an
intersection, LOM, or DME, that's an acceptable substitute for a locator
beacon.

The FAF on an ILS is glideslope intersect, not the LOM, DME etc which are
not required.

HIlton

"Hilton" wrote in message thlink.net...
Paul Tomblin wrote:
In a previous article, Barry said:
When doing an ILS approach, with the glideslope, is it a requirement to
be
able to identify the outer marker or a substitute? FAR 91.175(k) lists
the

"or a substitute" is the operative phrase. If the FAF is identified by an
intersection, LOM, or DME, that's an acceptable substitute for a locator
beacon.

The FAF on an ILS is glideslope intersect, not the LOM, DME etc which are
not required.

HIlton


Ahhh, but suppose your glideslope fails (onboard or on the ground)
after this "not required" intersection (with the "X" on Jepp charts)?
Suddenly you are doing a localizer approach and the FAF identification
becomes much more useful as a place from which you start your timing.


Lee

Lee Elson wrote:
Hilton wrote:
Paul Tomblin wrote:
In a previous article, Barry said:
When doing an ILS approach, with the glideslope, is it a requirement
to
be
able to identify the outer marker or a substitute? FAR 91.175(k)
lists
the

"or a substitute" is the operative phrase. If the FAF is identified
by an
intersection, LOM, or DME, that's an acceptable substitute for a
locator
beacon.

The FAF on an ILS is glideslope intersect, not the LOM, DME etc which
are
not required.

HIlton


Ahhh, but suppose your glideslope fails (onboard or on the ground)
after this "not required" intersection (with the "X" on Jepp charts)?
Suddenly you are doing a localizer approach and the FAF identification
becomes much more useful as a place from which you start your timing.

Lee,

I agree with you 100%. I was speaking from a legal view, not a safety view.
A few years ago, an approach's minimum changed if the outer marker was bust.
That is no longer the case.

To be picky, the ILS's FAF is the glideslope intersept, not the 'cross'.
The 'cross' belongs to the non-precision approach that just happens to be
printed on the same piece of paper.

Hilton

A few years ago, an approach's minimum changed if the outer marker was bust.
That is no longer the case.

I remember there used to be a penalty for a middle marker out of service, but
was the outer marker included on the table, too?

You tell the controller that you are executing the miss, go around, and get
set up for the LOC-only, if one exists. Changing from an ILS to a LOC in
midstream is not good practice...the assumption is that you briefed the ILS
(even if you are alone), not the LOC.

Bob Gardner

"Lee Elson" wrote in message
om...
"Hilton" wrote in message
thlink.net...
Paul Tomblin wrote:
In a previous article, Barry said:
When doing an ILS approach, with the glideslope, is it a requirement
to
be
able to identify the outer marker or a substitute? FAR 91.175(k)
lists
the

"or a substitute" is the operative phrase. If the FAF is identified
by an
intersection, LOM, or DME, that's an acceptable substitute for a
locator
beacon.

The FAF on an ILS is glideslope intersect, not the LOM, DME etc which
are
not required.

HIlton


Ahhh, but suppose your glideslope fails (onboard or on the ground)
after this "not required" intersection (with the "X" on Jepp charts)?
Suddenly you are doing a localizer approach and the FAF identification
becomes much more useful as a place from which you start your timing.


Lee

THat's how I do it, although I've had instructors doing my IPC ding me for not
starting the timer on an ILS. As politely as I can, I remind them that the
times are for a localizer only approach and that if the glideslope screws the
pooch, I'm going missed.

Bob Gardner wrote:

You tell the controller that you are executing the miss, go around, and get
set up for the LOC-only, if one exists. Changing from an ILS to a LOC in
midstream is not good practice...the assumption is that you briefed the ILS
(even if you are alone), not the LOC.

Bob Gardner--

--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."
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