KPAE ILS...Now Requires DME...Why?

I can't figure it out. Thoughts? Thanks.

Ethan

blackboxman wrote:
I can't figure it out. Thoughts? Thanks.

Ethan


The outer and middle markers can be replaced
by a DME. The DME responder is more expensive
than a marker, but it does not need separate
locations with the associated costs. The DME
is usually situated together with the glide
path equipment.

--

Tauno Voipio
tauno voipio (at) iki fi

On Mar 29, 1:58*pm, Tauno Voipio wrote:
blackboxman wrote:
I can't figure it out. *Thoughts? *Thanks.

Ethan

The outer and middle markers can be replaced
by a DME. The DME responder is more expensive
than a marker, but it does not need separate
locations with the associated costs. The DME
is usually situated together with the glide
path equipment.

--

Tauno Voipio
tauno voipio (at) iki fi

Looks like you need DME to identify the FAF if you're flying LOC
only. You wouldn't need it if you have the glideslope needle. (The
name could just as well be "LOC/DME or ILS RWY 16R".) Also, it's 1 nm
legs in the holding pattern for course reversal and missed approach.

wrote:

Looks like you need DME to identify the FAF if you're flying LOC
only.


There's a marker beacon there.



Also, it's 1 nm legs in the holding pattern for course reversal and missed
approach.


No, it's one minute.

On Mar 29, 7:29*pm, "Steven P. McNicoll"
wrote:
wrote:

Looks like you need DME to identify the FAF if you're flying LOC
only.

There's a marker beacon there.

Yeah, that's what's got me wondering -- there is a marker beacon, so
why the DME requirement? This approach didn't require DME when the
RITTS compass locator was there (I guess it's been or being
decommissioned). AIM 1-1-9 doesn't say that an ILS has to have both a
marker beacon AND DME or a compass locator.

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

blackboxman wrote:
On Mar 29, 7:29?pm, "Steven P. McNicoll"
wrote:
wrote:

Looks like you need DME to identify the FAF if you're flying LOC
only.

There's a marker beacon there.

Yeah, that's what's got me wondering -- there is a marker beacon, so
why the DME requirement? This approach didn't require DME when the
RITTS compass locator was there (I guess it's been or being
decommissioned). AIM 1-1-9 doesn't say that an ILS has to have both a
marker beacon AND DME or a compass locator.

Here's a question. If you lose the glideslope, or it goes OTS,
you would now need something to tell you the distance for the LOC,
right? And another question; it says that simultaneous reception of
I-PAE and PAE DME are required. If you lose one or the other (or if one
goes OTS), wouldn't that nix using the approach altogether?

BL.
- --
Brad Littlejohn | Email:
Unix Systems Administrator, |
Web + NewsMaster, BOFH.. Smeghead! | http://www.wizard.com/~tyketto
PGP: 1024D/E319F0BF 6980 AAD6 7329 E9E6 D569 F620 C819 199A E319 F0BF

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)

iD8DBQFJ0GOZyBkZmuMZ8L8RAjmUAKDTMiTs/TO8WbAlyC0O9AsAEO5gAwCg0uB/
CoA07/xC6HjWW/My91Z4RSE=
=BdNV
-----END PGP SIGNATURE-----

blackboxman wrote:

Yeah, that's what's got me wondering -- there is a marker beacon, so
why the DME requirement? This approach didn't require DME when the
RITTS compass locator was there (I guess it's been or being
decommissioned). AIM 1-1-9 doesn't say that an ILS has to have both a
marker beacon AND DME or a compass locator.


My guess is the OM is a normal powered fan marker and the fix
displacement error is too large for it to serve as a FAF, so DME
is required.

For a fix to be satisfactory for use as a FAF, the fix displacement error
should not exceed 1 mile. It may be as large as 2 miles when the MAP
is marked by overheading an air navigation facility (except 75 MHz
markers), or a buffer of equal length to the excessive fix error is
provided between the published MAP and the point where the missed
approach surface begins. A normal powered fan marker has a fix
displacement error of two miles, a low powered fan marker has a fix
displacement error of 1/2 mile. DME also has a fix displacement error
of 1/2 mile.

A Guy Called Tyketto wrote:

Here's a question. If you lose the glideslope, or it goes OTS,
you would now need something to tell you the distance for the LOC,
right?


No, you'd need something to mark the FAF.



And another question; it says that simultaneous reception of
I-PAE and PAE DME are required. If you lose one or the other (or if
one goes OTS), wouldn't that nix using the approach altogether?


It says simultaneous reception of I-PAE and PAE DME is required because the
DME source is PAE VOR/DME, not I-PAE localizer. The LOC/DME approach
requires two VHF NAV receivers for most users. If you lose I-PAE you cannot
fly the ILS or LOC/DME approach, if you lose PAE DME you cannot fly the
LOC/DME approach.

On Mar 28, 6:21*pm, blackboxman wrote:
I can't figure it out. *Thoughts? *Thanks.

Ethan

The approach is labeled ILS or LOC/DME. DME is required for the LOC
approach only to identify the FAF.

Maurice Givens

VOR-DME wrote:

If it were a VOR-DME this would make sense, because of the potentially
reduced lateral precision of the VOR compared to an ILS, however on a
LOC approach the marker that is there is sufficient to locate the FAF.


Maybe not.

For a fix to be satisfactory for use as a FAF, the fix error should not
exceed +/- 1 mile. It may be as large as +/- 2 miles when the missed
approach point is marked by overheading a navaid, except for 75 MHz markers;
or a buffer of equal length to the excessive fix error is provided between
the published missed approach point and the point where the missed approach
surface begins. A normal powered fan marker has a fix error of +/- 2 miles,
a low powered fan marker has a fix error of +/- 1/2 mile.


Even though it is labelled ILS or LOC/DME the note requiring
reception of both is not specific to the LOC approach.


Where is DME used on this approach? At WEBVE and JUGBA. WEBVE is used on
the ILS and LOC/DME approaches but it's also an intersection with a CVV
radial so it can be identified without DME. On the ILS you'd leave 3000'
MSL on the glideslope and begin the missed approach procedure at DH. On the
LOC/DME you'd leave 3000' at the FAF, JUGBA, and also start your timing for
the missed approch there. JUGBA FAF is used only on the LOC/DME approach
and it appears the OM alone isn't sufficient to be a FAF, thus DME is
required only for the LOC/DME approach.


I'm guessing they are requiring the DME reception because of the
missed approach. Tracking outbound on 338 PAE they want you to use
13.9 DME to identify WEBVE INT. How far away is the Penn Cove VORTAC?


It's 18.3 miles from WEBVE, and the divergence angle of 70 degrees with the
localizer puts iy well within the fix displacement limits of an
intersection. Note that WEBVE is identified as INT on the plate.