Interesting Approach

luvflyin said:
He didn’t say anything about “reception.” He said “identify.” GPS is an authorized substitute for an Intersection, which MORUS is.
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Whatever, it still doesn't change the issue. Why does MORUS have to do with the minima?
 
MauleSkinner said:
And why does adding VOR get you lower minimums?
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Because the freaking plate says so. You could use GPS for idnetifying MORUS, but it won't let you get the VOR/NDB minima.
 
flyingron said:
Because the freaking plate says so. You could use GPS for idnetifying MORUS, but it won't let you get the VOR/NDB minima.
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Yeah. That’s what it says. NDB/VOR MINIMUMS. It’s clear though that VOR is about being able to go lower because MORUS identifies a point when you are past an obstruction that holds you at 980. It can have nothing to do with VOR having more precise lateral accuracy than ADF. It can have nothing to do with VOR more precisely identifying the Missed Approach Point. While VOR is used for Feeder Routes to the IAF, it does nothing on the Approach but identify the Step Down Fix. This is an Army Chart. An FAA Chart would have said MORUS FIX MINIMUMS. But yeah, it don’t say that, it says NDB/VOR MINIMUMS. So by the ‘letter of the law’ so to speak, you are right. If I needed the lower MDA to get down and land I would have no qualms with going by the ‘intent’ on this Approach.
 
flyingron said:
Yep, the FAA pretty much ditched all the overlay ("or GPS") approaches years ago. Airports got their own straight GPS approaches instead.
As pointed out, since there was no real "redesign" of the approach for GPS overlays, higher GPS minima were not uncommon.
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There are still some around. GPS overlays are deleted as an approach is revised. KEMT, for example, last year had the VOR-A or GPS revised to VOR-A. The VOR-B or GPS is still an overlay, pending the scheduled publication of the RNAV-B on December 5.
 
MauleSkinner said:
And why does adding VOR get you lower minimums?
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Because it provides a step-down fix in the final segment to clear an obstacle prior to MORUS. In an on-airport, no FAF approach like this one, any stepdown fix has to be within 4 miles of the runway because entry into the final segment varies by pilot technique. This type of NDB approach requires 350 feet of obstacle clearance (ROC) but that becomes 300 feet inside the step-down fix (MORUS).
 
aterpster said:
Because it provides a step-down fix in the final segment to clear an obstacle prior to MORUS. In an on-airport, no FAF approach like this one, any stepdown fix has to be within 4 miles of the runway because entry into the final segment varies by pilot technique. This type of NDB approach requires 350 feet of obstacle clearance (ROC) but that becomes 300 feet inside the step-down fix (MORUS).
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And, per @flyingron ’s post, you cannot identity to use those minima with GPS?
 
aterpster said:
Because it provides a step-down fix in the final segment to clear an obstacle prior to MORUS. In an on-airport, no FAF approach like this one, any stepdown fix has to be within 4 miles of the runway because entry into the final segment varies by pilot technique. This type of NDB approach requires 350 feet of obstacle clearance (ROC) but that becomes 300 feet inside the step-down fix (MORUS).
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Ah, that ROC is reduced closer in makes sense. I was thinking that 716 foot obstruction South of the Approach course would have been the obstruction accounting for it. It’s about 4.5 miles off to the side. Do you think that could be part of it?
 
luvflyin said:
Ah, that ROC is reduced closer in makes sense. I was thinking that 716 foot obstruction South of the Approach course would have been the obstruction accounting for it. It’s about 4.5 miles off to the side. Do you think that could be part of it?
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I see 724. But, that would mandate 1080 prior to MORUS unless it is in the secondary area. Not really possible to determine without the documentation.
 
350C2C9C-8CDD-44AA-8EAB-E26BCC8AF8BF.jpeg Another NDB with a crossing VOR radial.
 
aterpster said:
That's different than a step-down fix for lower minimums. In this case the VOR is required for entering the final approach segment. Had the FAA designed this IAP, the briefing strip would state "VOR Required."
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Or RADAR
 
luvflyin said:
Or RADAR
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If there is ATC radar and if the ATC facility that controls the airspace agrees to call it as a radar fix. That all has to be coordinated before the procedure can be published with a charted ATC radar fix.

Having said that, can a step-down fix be called out by ATC on an ad hoc basis? Yes, if the fix is on their video map and they agree to call it.
 
aterpster said:
If there is ATC radar and if the ATC facility that controls the airspace agrees to call it as a radar fix. That all has to be coordinated before the procedure can be published with a charted ATC radar fix.

Having said that, can a step-down fix be called out by ATC on an ad hoc basis? Yes, if the fix is on their video map and they agree to call it.
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Yeah, there's no ATC rule I've seen that a Fix must be indicated as a 'Radar Fix' for a Controller to call it. Of course it has to be on the Video Map in order to that. Whether or not the pilot can, or should, accept that to identify passing a fix is covered in AIM 5-4-7 g.

g. Pilots should not rely on radar to identify a fix
unless the fix is indicated as “RADAR” on the IAP.
Pilots may request radar identification of an OM, but
the controller may not be able to provide the service
due either to workload or not having the fix on the
video map.

What should be in the briefing strip on the Approach we are talking about above in post #49? AIM 5-4-5 a. 3. (b) says

....When radar or other equipment is required on
portions of the procedure outside the final approach
segment, including the missed approach, a note will
be charted in the notes box of the pilot briefing
portion of the approach chart (e.g., RADAR
REQUIRED or DME REQUIRED). Notes are not
charted when VOR is required outside the final
approach segment....

So here we have an Approach where you need either VOR or RADAR. If VOR is not supposed to be 'noted' on the Chart, that just leaves RADAR required to be put there. But RADAR is not required if you have VOR. So should it say "VOR or RADAR required" even though the basic rule so to speak is that notes are not charted when it's VOR that is required. Or should it say "Or RADAR required?" (that's just silly of course). Just an academic discussion. The Plan and Profile views speak for themselves.
 
luvflyin said:
Yeah, there's no ATC rule I've seen that a Fix must be indicated as a 'Radar Fix' for a Controller to call it. Of course it has to be on the Video Map in order to that. Whether or not the pilot can, or should, accept that to identify passing a fix is covered in AIM 5-4-7 g.

g. Pilots should not rely on radar to identify a fix
unless the fix is indicated as “RADAR” on the IAP.
Pilots may request radar identification of an OM, but
the controller may not be able to provide the service
due either to workload or not having the fix on the
video map.

What should be in the briefing strip on the Approach we are talking about above in post #49? AIM 5-4-5 a. 3. (b) says

....When radar or other equipment is required on
portions of the procedure outside the final approach
segment, including the missed approach, a note will
be charted in the notes box of the pilot briefing
portion of the approach chart (e.g., RADAR
REQUIRED or DME REQUIRED). Notes are not
charted when VOR is required outside the final
approach segment....

So here we have an Approach where you need either VOR or RADAR. If VOR is not supposed to be 'noted' on the Chart, that just leaves RADAR required to be put there. But RADAR is not required if you have VOR. So should it say "VOR or RADAR required" even though the basic rule so to speak is that notes are not charted when it's VOR that is required. Or should it say "Or RADAR required?" (that's just silly of course). Just an academic discussion. The Plan and Profile views speak for themselves.
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This is the directive for FAA procedure designers:
 

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