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

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.

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?

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.

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.

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.

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.

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.

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