SAC ILS "ADF Required" Info

Steven P. McNicoll wrote:
"Sam Spade" wrote in message
news:O9ekg.179076$bm6.79817@fed1read04...

They have their reasons, and sometimes their reasons are not very sound.



As in this case. Bottom line is ADF does not provide any information needed
to fly this approach.


Some times, as in this case, it's hard (or impossible) to understand the
reason behind a "Chart planview note: ADF required". Usually that would
be there if the LOM is needed for procedure entry, and in this case it
would only be required for procedure entry if NORCAL can't vector
aircraft to final for some reason. Is NORCAL able to vector aircraft to
this final approach course at a suitable altitude? If not, that would
explain the ADF required note. Perhaps "ADF or RADAR required" would
have been more appropriate.
It wouldn't be charted that way just for the sake of the LOC portion,
because if that was the case, they would have changed the title of the
procedure to indicate the extra equipment required for the non-precision
final. Assuming the outer marker works, then ADF would not be required
for the LOC FAF, because the OM would take care of that.
The ILS doesn't need the LOM for final since it relies on glideslope
intercept, and not the non-precision FAF.
In this case the LOM is not required for missed approach, as the MA
instructions give the option to go to the VORTAC.
It would be nice if the procedure could include the reason the ADF is
required, i.e., "ADF required for missed approach" or "ADF required for
procedure entry when radar OTS".

It appears this procedure can be completed via radar vectors to final,
then glideslope intercept (ILS) or OM (LOC), followed by MA back to SAC
VORTAC. Don't see a need for the ADF as long as NORCAL can vector to final.

Guess this is just one of lifes mysteries.

JPH

"JPH" wrote in message
news:qAmkg.7416$f76.6314@dukeread06...

Some times, as in this case, it's hard (or impossible) to understand the
reason behind a "Chart planview note: ADF required". Usually that would
be there if the LOM is needed for procedure entry, and in this case it
would only be required for procedure entry if NORCAL can't vector aircraft
to final for some reason. Is NORCAL able to vector aircraft to this final
approach course at a suitable altitude? If not, that would explain the ADF
required note. Perhaps "ADF or RADAR required" would have been more
appropriate.
It wouldn't be charted that way just for the sake of the LOC portion,
because if that was the case, they would have changed the title of the
procedure to indicate the extra equipment required for the non-precision
final. Assuming the outer marker works, then ADF would not be required for
the LOC FAF, because the OM would take care of that.
The ILS doesn't need the LOM for final since it relies on glideslope
intercept, and not the non-precision FAF.
In this case the LOM is not required for missed approach, as the MA
instructions give the option to go to the VORTAC.
It would be nice if the procedure could include the reason the ADF is
required, i.e., "ADF required for missed approach" or "ADF required for
procedure entry when radar OTS".

It appears this procedure can be completed via radar vectors to final,
then glideslope intercept (ILS) or OM (LOC), followed by MA back to SAC
VORTAC. Don't see a need for the ADF as long as NORCAL can vector to
final.

Guess this is just one of lifes mysteries.


Where do you see a need for ADF without vectors to final?

On 06/16/06 08:19, Steven P. McNicoll wrote:
"JPH" wrote in message
news:qAmkg.7416$f76.6314@dukeread06...

Some times, as in this case, it's hard (or impossible) to understand the
reason behind a "Chart planview note: ADF required". Usually that would
be there if the LOM is needed for procedure entry, and in this case it
would only be required for procedure entry if NORCAL can't vector aircraft
to final for some reason. Is NORCAL able to vector aircraft to this final
approach course at a suitable altitude? If not, that would explain the ADF
required note. Perhaps "ADF or RADAR required" would have been more
appropriate.
It wouldn't be charted that way just for the sake of the LOC portion,
because if that was the case, they would have changed the title of the
procedure to indicate the extra equipment required for the non-precision
final. Assuming the outer marker works, then ADF would not be required for
the LOC FAF, because the OM would take care of that.
The ILS doesn't need the LOM for final since it relies on glideslope
intercept, and not the non-precision FAF.
In this case the LOM is not required for missed approach, as the MA
instructions give the option to go to the VORTAC.
It would be nice if the procedure could include the reason the ADF is
required, i.e., "ADF required for missed approach" or "ADF required for
procedure entry when radar OTS".

It appears this procedure can be completed via radar vectors to final,
then glideslope intercept (ILS) or OM (LOC), followed by MA back to SAC
VORTAC. Don't see a need for the ADF as long as NORCAL can vector to
final.

Guess this is just one of lifes mysteries.


Where do you see a need for ADF without vectors to final?



When told to head direct EXECC (IAF) and fly the approach pilot-nav.
Technically, EXECC is the IAF, not the VOR. However, because they are
so close, I think most pilots just use the VOR.


--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

"Mark Hansen" wrote in message
...

When told to head direct EXECC (IAF) and fly the approach pilot-nav.
Technically, EXECC is the IAF, not the VOR. However, because they are
so close, I think most pilots just use the VOR.


There's a feeder route from the VOR to EXECC. There's no need for ADF on
this approach, the note "ADF REQUIRED" is an error.

There's no need for ADF on
this approach, the note "ADF REQUIRED" is an error.

It may be an error, but it is an error with which the pilot has to comply.

Jose
--
The price of freedom is... well... freedom.
for Email, make the obvious change in the address.

"Jose" wrote in message
. com...

It may be an error, but it is an error with which the pilot has to comply.


It's definitely an error. How would the pilot comply with it?

On 06/16/06 09:23, Steven P. McNicoll wrote:
"Mark Hansen" wrote in message
...

When told to head direct EXECC (IAF) and fly the approach pilot-nav.
Technically, EXECC is the IAF, not the VOR. However, because they are
so close, I think most pilots just use the VOR.


There's a feeder route from the VOR to EXECC. There's no need for ADF on
this approach, the note "ADF REQUIRED" is an error.



But the VOR is not an IAF and doesn't provide a NoPT route to EXECC,
so when you get to EXECC you still need to execute the procedure turn.

Do you agree that the procedure turn should be made about EXECC?

When coming from the north, the pilot is going to have to make a u-turn
at the VOR, then, while in the zone of confusion, follow the 018 degree
radial to find the LOM... whew.

Do you think we should be able to identify the fix for the PT using
the marker beacons? A marker beacon receiver isn't required. What if the
plane doesn't have one?

I think the ADF receiver makes this scenario much simpler for the pilot,
and that was the reason for requiring it to execute the approach.

--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

"Mark Hansen" wrote in message
...

But the VOR is not an IAF and doesn't provide a NoPT route to EXECC,
so when you get to EXECC you still need to execute the procedure turn.


The issue is not on what conditions a PT is required, it's why the note "ADF
REQUIRED" appears on this IAP.



Do you agree that the procedure turn should be made about EXECC?

When coming from the north, the pilot is going to have to make a u-turn
at the VOR, then, while in the zone of confusion, follow the 018 degree
radial to find the LOM... whew.

Do you think we should be able to identify the fix for the PT using
the marker beacons? A marker beacon receiver isn't required. What if the
plane doesn't have one?

I think the ADF receiver makes this scenario much simpler for the pilot,
and that was the reason for requiring it to execute the approach.


What am I required to use the ADF for if I'm cleared for this approach while
inbound on V6 southwest of COUPS?

On 06/17/06 16:52, Steven P. McNicoll wrote:
"Mark Hansen" wrote in message
...

But the VOR is not an IAF and doesn't provide a NoPT route to EXECC,
so when you get to EXECC you still need to execute the procedure turn.


The issue is not on what conditions a PT is required, it's why the note "ADF
REQUIRED" appears on this IAP.



Do you agree that the procedure turn should be made about EXECC?

When coming from the north, the pilot is going to have to make a u-turn
at the VOR, then, while in the zone of confusion, follow the 018 degree
radial to find the LOM... whew.

Do you think we should be able to identify the fix for the PT using
the marker beacons? A marker beacon receiver isn't required. What if the
plane doesn't have one?

I think the ADF receiver makes this scenario much simpler for the pilot,
and that was the reason for requiring it to execute the approach.


What am I required to use the ADF for if I'm cleared for this approach while
inbound on V6 southwest of COUPS?

Because from COUPS your to fly the bearing to the LOM. The notes on
the feeder route say: "1400 NoPT to LOM 015".

Now, as to why they did *that*, I don't know. From COUPS, I think
everyone just gets lined up on the localizer.

Here's another problem with this procedu From COUPS, it says that
the LOM is 015 degrees. However, the VOR is 016 degrees. That puts
the LOM to the left of the VOR (when looking from COUPS). However,
it also says that the LOM is 018 degrees from the VOR. That puts it
to the right of the VOR (again, when looking from COUPS).

Is this a rounding error, or am I missing something?


--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

Steven P. McNicoll wrote:
"Mark Hansen" wrote in message
...

When told to head direct EXECC (IAF) and fly the approach pilot-nav.
Technically, EXECC is the IAF, not the VOR. However, because they are
so close, I think most pilots just use the VOR.



There's a feeder route from the VOR to EXECC. There's no need for ADF on
this approach, the note "ADF REQUIRED" is an error.


Yes, but it's only a feeder route. SAC VORTAC is not an IAF nor an IF,
it's just a feeder to the IAF at the LOM. From the LOM, you need to do a
course reversal based on how the procedure was designed, and if you
don't have capability to receive the LOM, then you can't do the course
reversal.
Why do you have to do a course reversal at the LOM? Because from a TERPS
construction viewpoint, SAC VORTAC doesn't meet the TERPS criteria for
intercepting final prior to the glideslope intercept point for the ILS
(TERPS Vol IV para 2.3.1), so you can't do a straight-in from SAC VORTAC
legally. And without the LOM, you can't do the LOC because you can't
identify the FAF (EXECC is not an intersection).
Now, if SAC VORTAC was further out, then it could provide a route to
intercept the LOC further out from the FAF (minimum length for an
intermediate segment on ILS is 1 NM, and SAC VORTAC is only 0.4 NM from
the non-precision FAF and even less from the glideslope intercept and it
goes to the LOM, and not necessarily the LOC depending on how far off
centerline the LOM is).

JPH