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

[blackboxman]

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

Ethan

[Tauno Voipio]

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

[[email protected]]

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.

[Steven P. McNicoll[_2_]]

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.

[blackboxman]

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.

[A Guy Called Tyketto]

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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

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[Steven P. McNicoll[_2_]]

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.

[Steven P. McNicoll[_2_]]

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.

[[email protected]]

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

[Steven P. McNicoll[_2_]]

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.

[Steven P. McNicoll[_2_]]

VOR-DME wrote:
>
> Yeah - I didn't see the (18.3) at first glance. I have to agree
> that's well within tolerance for identifying the int. I was thinking
> it was perhaps twice that far. I also agree that the naming
> convention would indicate that the DME is only required for the LOC
> approach, so your interpretation makes sense even if intuitively one
> doesn't expect to need DME to identify a FAF when there's a marker.
>

Given that a marker isn't used alone, that it's only purpose is to fix
position along a track formed by another navaid, one would think that the OM
would be sufficient to define the FAF. Not so. Reception of the marker on
the glideslope at 3000' MSL assures the pilot that he's not on a false
glideslope while flying the ILS, but it's not good enough alone to serve as
a FAF on the localizer approach.

[VOR-DME]

In article
>,
says...
>
>
>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.
>

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.

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

[VOR-DME]

In article >,
says...
>
>

>>
>> 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.
>
>


Yeah - I didn't see the (18.3) at first glance. I have to agree that's well
within tolerance for identifying the int. I was thinking it was perhaps twice
that far. I also agree that the naming convention would indicate that the DME
is only required for the LOC approach, so your interpretation makes sense even
if intuitively one doesn't expect to need DME to identify a FAF when there's a
marker.

[wegmand]

On Apr 6, 10:59*am, "Steven P. McNicoll" >
wrote:
> VOR-DME wrote:
>
> > Yeah - I didn't see the (18.3) at first glance. I have to agree
> > that's well within tolerance for identifying the int. I was thinking
> > it was perhaps twice that far. I also agree that the naming
> > convention would indicate that the DME is only required for the LOC
> > approach, so your interpretation makes sense even if intuitively one
> > doesn't expect to need DME to identify a FAF when there's a marker.
>
> Given that a marker isn't used alone, that it's only purpose is to fix
> position along a track formed by another navaid, one would think that the OM
> would be sufficient to define the FAF. *Not so. *Reception of the marker on
> the glideslope at 3000' MSL assures the pilot that he's not on a false
> glideslope while flying the ILS, but it's not good enough alone to serve as
> a FAF on the localizer approach.

Also - An airplane's ILS installation would have to include the marker
beacon receiver but if the airplane only has a single VOR receiver (no
glideslope), the only way left to identify the FAF is with DME, right?

[Steven P. McNicoll[_2_]]

wegmand wrote:
>
> Also - An airplane's ILS installation would have to include the marker
> beacon receiver but if the airplane only has a single VOR receiver (no
> glideslope), the only way left to identify the FAF is with DME, right?
>

Yes, that's why it's a LOC/DME approach.

[AlexB]

On Apr 7, 5:43*pm, wegmand > wrote:
> ...
> Also - An airplane's ILS installation would have to include the marker
> beacon receiver but if the airplane only has a single VOR receiver (no
> glideslope), the only way left to identify the FAF is with DME, right?

Now I was always thought that on an ILS the FAF was defined by
glideslope intercept which is the little lightning bolt on the NOS
plates. MAP was defined by being on GS and reaching the DA/DH.

I've been watching this plate and have been waving my flag since they
did this. I've got VOR and DME in my a/c but no ADF so I used to be
excluded from KPAE (or at leased forced onto the VOR approach) which
sucks because I'm based on KBFI. It looks like they've been adding DME
as a set of upgrades. Looking at the plates KTIW also decomissioned
their LOM and went to an ILS/DME setup the same as KPAE.

Alex.

[Steven P. McNicoll[_2_]]

AlexB wrote:
>
> Now I was always thought that on an ILS the FAF was defined by
> glideslope intercept which is the little lightning bolt on the NOS
> plates. MAP was defined by being on GS and reaching the DA/DH.
>
> I've been watching this plate and have been waving my flag since they
> did this. I've got VOR and DME in my a/c but no ADF so I used to be
> excluded from KPAE (or at leased forced onto the VOR approach) which
> sucks because I'm based on KBFI. It looks like they've been adding DME
> as a set of upgrades. Looking at the plates KTIW also decomissioned
> their LOM and went to an ILS/DME setup the same as KPAE.
>

Neither KPAE nor KTIW have an ILS/DME approach. There's no such animal. At
KPAE DME is required for the LOC/DME RWY 16R and VOR/DME RWY 16R approaches,
KTIW does not require DME for any approach.

[AlexB]

On Apr 10, 1:12*pm, "Steven P. McNicoll" >
wrote:
> AlexB wrote:
>
> > Now I was always thought that on an ILS the FAF was defined by
> > glideslope intercept which is the little lightning bolt on the NOS
> > plates. MAP was defined by being on GS and reaching the DA/DH.
>
> > I've been watching this plate and have been waving my flag since they
> > did this. I've got VOR and DME in my a/c but no ADF so I used to be
> > excluded from KPAE (or at leased forced onto the VOR approach) which
> > sucks because I'm based on KBFI. It looks like they've been adding DME
> > as a set of upgrades. Looking at the plates KTIW also decomissioned
> > their LOM and went to an ILS/DME setup the same as KPAE.
>
> Neither KPAE nor KTIW have an ILS/DME approach. *There's no such animal.. *At
> KPAE DME is required for the LOC/DME RWY 16R and VOR/DME RWY 16R approaches,
> KTIW does not require DME for any approach.

You've just sent me off to the plates and you're quite right!

I'm still pleased about the dropping the ADF requirement though.

I don't have any of the old plates around. Did all this coincide with
removing the LOM? I definitely remember that PAE had one but don't
remember TIW.

Alex.

[Steven P. McNicoll[_2_]]

AlexB wrote:
>
> You've just sent me off to the plates and you're quite right!
>
> I'm still pleased about the dropping the ADF requirement though.
>
> I don't have any of the old plates around. Did all this coincide with
> removing the LOM? I definitely remember that PAE had one but don't
> remember TIW.
>

I have plates from February 1998. The FAF for the KPAE ILS RWY 16R
localizer approach was RITTS LOM, it was also the IAF and the missed
approach holding fix. The KTIW ILS RWY 17 of that time was AMDT 8, the only
significant difference between it and the present AMDT 8A appears to be the
removal of the MM.

[Ross]

Steven P. McNicoll wrote:
> AlexB wrote:
>> You've just sent me off to the plates and you're quite right!
>>
>> I'm still pleased about the dropping the ADF requirement though.
>>
>> I don't have any of the old plates around. Did all this coincide with
>> removing the LOM? I definitely remember that PAE had one but don't
>> remember TIW.
>>
>
> I have plates from February 1998. The FAF for the KPAE ILS RWY 16R
> localizer approach was RITTS LOM, it was also the IAF and the missed
> approach holding fix. The KTIW ILS RWY 17 of that time was AMDT 8, the only
> significant difference between it and the present AMDT 8A appears to be the
> removal of the MM.
>
>

When they first commissioned the ILS RWY 17L to KGYI they had a ADF
required for the hold. I never understood why you couldn't use the
localizer, the outer marker, and or the 302 degree radial to define the
holding point. I sent a letter to the designers, and they came back
saying in their haste that they did make it more complicated. They moved
the hold to URH VOR that was some 30 miles away. I withdrew my request
and they went back to the ADF required on the approach.

My idea was to fly the missed approach, to to fly the local backwards to
intercept the 302 degree radial and hold. But the designers didn't like
that.

--

Regards, Ross
C-172F 180HP
Sold :(
KSWI

[Steven P. McNicoll[_2_]]

Ross wrote:
>
> When they first commissioned the ILS RWY 17L to KGYI they had a ADF
> required for the hold. I never understood why you couldn't use the
> localizer, the outer marker, and or the 302 degree radial to define
> the holding point. I sent a letter to the designers, and they came
> back saying in their haste that they did make it more complicated.
> They moved the hold to URH VOR that was some 30 miles away. I
> withdrew my request and they went back to the ADF required on the
> approach.
> My idea was to fly the missed approach, to to fly the local backwards
> to intercept the 302 degree radial and hold. But the designers didn't
> like that.
>

If RIBBY OM is good enough to be a FAF on the localizer approach it should
be good enough to be holding fix. I would think a missed approach procedure
could have a heading back to the localizer and fly the localizer to hold at
the OM. But what's the problem with ADF? Who'd be flying this approach
with a marker beacon receiver but without ADF or GPS used in lieu of ADF?

[Ross]

Steven P. McNicoll wrote:
> Ross wrote:
>> When they first commissioned the ILS RWY 17L to KGYI they had a ADF
>> required for the hold. I never understood why you couldn't use the
>> localizer, the outer marker, and or the 302 degree radial to define
>> the holding point. I sent a letter to the designers, and they came
>> back saying in their haste that they did make it more complicated.
>> They moved the hold to URH VOR that was some 30 miles away. I
>> withdrew my request and they went back to the ADF required on the
>> approach.
>> My idea was to fly the missed approach, to to fly the local backwards
>> to intercept the 302 degree radial and hold. But the designers didn't
>> like that.
>>
>
> If RIBBY OM is good enough to be a FAF on the localizer approach it should
> be good enough to be holding fix. I would think a missed approach procedure
> could have a heading back to the localizer and fly the localizer to hold at
> the OM. But what's the problem with ADF? Who'd be flying this approach
> with a marker beacon receiver but without ADF or GPS used in lieu of ADF?
>
>
>

When I first started instrument training I didn't have a ADF but did
have a IFR GPS. So, for me it was immaterial. I could still fly it. But
my thinking (engineer), and as you stated, was this could be
accomplished without the need for requiring an ADF, yet it was put on
the IAP and my thinking (again) unnecessary.

--

Regards, Ross
C-172F 180HP
Sold :(
KSWI