Strange NoPT restriction?

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juansg

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Juan Sanchez
Hi all,

looking at Sacramento Mather (MHR) VOR RWY 4R approach, I see a "NoPT for arrivals on SAC VORTAC airway radials 195 CW 216" note. If I understand this correctly, unless you're in within that 21 degree slice, you'd need to do a HILPT.

I've seen that type of restriction before to avoid having to make really sharp turns. What I don't get is that in this case, this seems very restrictive. Even if an airplane was coming from the west inbound on R-225 (heading 045 to SAC), fully aligned with the Final Approach course, it still would need to do one loop in the hold before proceeding to the approach? (assuming pilot nav, no vectors or cleared straight in approach). Am I missing something? Thanks!

Approach in question: https://resources.globalair.com/dtpp/globalair_00356V4R.PDF
 
I would agree with your assessment. And, yes, it does seem strange. Note that the RNAV(GPS) approach for 4R only has one NoPT path as well. I'd guess, chances are with radar, ATC might clear for straight-in anyway.
 
juansg said:
Hi all,

looking at Sacramento Mather (MHR) VOR RWY 4R approach, I see a "NoPT for arrivals on SAC VORTAC airway radials 195 CW 216" note. If I understand this correctly, unless you're in within that 21 degree slice, you'd need to do a HILPT.

I've seen that type of restriction before to avoid having to make really sharp turns. What I don't get is that in this case, this seems very restrictive. Even if an airplane was coming from the west inbound on R-225 (heading 045 to SAC), fully aligned with the Final Approach course, it still would need to do one loop in the hold before proceeding to the approach? (assuming pilot nav, no vectors or cleared straight in approach). Am I missing something? Thanks!

Approach in question: https://resources.globalair.com/dtpp/globalair_00356V4R.PDF
Click to expand...
My guess is that the designer wanted to include only the two airways that had 2,000' MEAs. There is no requirement to be that restrictive. Or, perhaps NorCal had some reason during procedure coordination.
 
juansg said:
Hi all,

looking at Sacramento Mather (MHR) VOR RWY 4R approach, I see a "NoPT for arrivals on SAC VORTAC airway radials 195 CW 216" note. If I understand this correctly, unless you're in within that 21 degree slice, you'd need to do a HILPT.

I've seen that type of restriction before to avoid having to make really sharp turns. What I don't get is that in this case, this seems very restrictive. Even if an airplane was coming from the west inbound on R-225 (heading 045 to SAC), fully aligned with the Final Approach course, it still would need to do one loop in the hold before proceeding to the approach? (assuming pilot nav, no vectors or cleared straight in approach). Am I missing something? Thanks!

Approach in question: https://resources.globalair.com/dtpp/globalair_00356V4R.PDF
Click to expand...

Probably because those two airway radials are V150 and V6 with MEA’s of 2000 and a shallow angle. The other airways to SAC have higher MEA’s. It would be about altitude loss. Doesn’t seem like that big an issue, but TERP’s has it’s rules.
 
aterpster said:
My guess is that the designer wanted to include only the two airways that had 2,000' MEAs. There is no requirement to be that restrictive. Or, perhaps NorCal had some reason during procedure coordination.
Click to expand...

Lol. I knew you’d be along soon, just not as I was typing. I can’t see a reason ATC would have requested that.
 
luvflyin said:
Probably because those two airway radials are V150 and V6 with MEA’s of 2000 and a shallow angle. The other airways to SAC have higher MEA’s. It would be about altitude loss. Doesn’t seem like that big an issue, but TERP’s has it’s rules.
Click to expand...
Some of the other airways meet descent gradient requirements, too. Perhaps the designer didn't want to include the others for profile view consistency. In any case, it's all academic come August 13:
CA_KMHR_VOR RWY 4R_CANCEL.jpg
 
Note also that the NoPT is for airways within that slice, not random routes.
 
I will also add that the procedure is rather old, the FAA's IFP Gateways shows a 2002 minor amendment (Orig-D) and two minor amendments since then via NOTAM. But the actual Original procedure is not available. It could have been significantly before that. Airways could have been created and removed in the years since the original was published. This is not a full and satisfying answer, since the "NoPT via..." note could have been updated via minor amendment.

And, as Wally pointed out, it's being canceled in 2 months anyway.
 
I've noticed that when you see a weird restriction like that on an approach chart, go to the low-enroute chart to get the context. As Wally mentioned above, the restriction limits No-PT to arrivals from the southwest on victor airways V6 and V150. It kind of makes sense when you think about it...if you're not on a victor airway, you've got radar coverage and the controller can vector you in to join the approach without a PT. If you were arriving on one of the other victor airways, such as V494 from the west or V334/392 from the south, the heading change would be too significant to skip the PT.
 
RussR said:
I will also add that the procedure is rather old, the FAA's IFP Gateways shows a 2002 minor amendment (Orig-D) and two minor amendments since then via NOTAM. But the actual Original procedure is not available. It could have been significantly before that. Airways could have been created and removed in the years since the original was published. This is not a full and satisfying answer, since the "NoPT via..." note could have been updated via minor amendment.

And, as Wally pointed out, it's being canceled in 2 months anyway.
Click to expand...
Plus, it was a USAF base when this procedure came about. :)
 
thanks so much for the help everybody. I should've paid more attention to the "airway" keyword and look at the Low-enroute chart. Now it makes much more sense. Thanks!
 
juansg said:
thanks so much for the help everybody. I should've paid more attention to the "airway" keyword and look at the Low-enroute chart. Now it makes much more sense. Thanks!
Click to expand...
This is the Jeppesen chart:
MHR VOR 04.jpg
 
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