HPILPT - Why no NoPT? RNAV 31 1L7

[flyingcheesehead]

Hi all,

Reference this plate:


When approaching via either transition route (HASSL or RASCO)... There is no "NoPT", and while UVCEH is both IAF and IF, neither HASSL nor RASCO is an IAF, the routes are charted as transition routes and not procedure routes, and this is not a TAA/T approach.

My read of this plate is that you would fly the transition, do a turn in the hold, and then fly inbound... But why? Especially from HASSL, you can't get any lower than you already can be on the transition.

What am I missing?

 

[4RNB]

I misread things

 

[FORANE]

Hi all,

Reference this plate:

View attachment 133788
When approaching via either transition route (HASSL or RASCO)... There is no "NoPT", and while UVCEH is both IAF and IF, neither HASSL nor RASCO is an IAF, the routes are charted as transition routes and not procedure routes, and this is not a TAA/T approach.

My read of this plate is that you would fly the transition, do a turn in the hold, and then fly inbound... But why? Especially from HASSL, you can't get any lower than you already can be on the transition.

What am I missing?

I concur. Purely guessing as I'm not a plate designer they were concerned about the 7500 point southwest of the course.

If I were based there I would likely request vectors, UVCEH, straight in.

 

[midlifeflyer]

What am I missing?

The possibility of an error?

I can see a reason for the PT for the RASCO transition. That extra 500' brings the descent from UVSEH to the FAF to more than 3 degrees. But with a crossing at 9500 at UVSEH regardless of whether or not you do the PT, that reason would not apply.

Realistically, I would expect someone coming in via either transition to be cleared straight in if requested. ATC might do that automatically but if not, I would definitely ask.

 

[Noah Lorang]

I'm guessing it wasn't made as a TAA because it would be hard to construct sectors that provide obstacle clearance without requiring an overly steep descent gradient. RASCO/HASSL are also pretty far from UVCEH (25 NM), which is too far from the IF to be IAFs in a TAA (8260.58C 2-4-2(a)(2)). My first guess what that those waypoints were picked to provide a lower MEA, but a look at the sectional makes me think you could do a traditional 90 degree T-fix setup and not have any higher of an MEA.

I kind of suspect it has something to do with allowable cross track error and lead in to turns between an IAF and IF vs the obstacle clearance provided by the HILPT (which would guarantee you're on the final approach course prior to UVCEH), which could put you in conflict with the 7500 point SW of the final approach course. I tried to figure it out from 8260.3 and 8260.58, but I couldn't find a smoking gun for what exactly is the problem with having those segments be initial approach segments, other than the length limit on a TAA.

The procedure is under revision per the IFP Information Gateway, expected to be completed by 6/12/2025, so who knows, maybe they're coming up w/ a proper TAA.

 

[dtuuri]

My read of this plate is that you would fly the transition, do a turn in the hold, and then fly inbound... But why? Especially from HASSL, you can't get any lower than you already can be on the transition.

You CAN get lower — 7700 MSL right after crossing UVCEH if you go straight-in, but you're aimed right for a 7500 MSL peak. At high IAS and turn radius you're possibly going to get too close for TERPs comfort, imo. TERPs might assume a random pilot could fly over the waypoint and descend immediately.

 

[RussR]

I cannot find a reason these shouldn't be IAFs.

Your best bet is to contact the FAA TERPS office and ask the same question. As this procedure is also being amended (as noted above), it would be a good opportunity to have some input into the amendment.

https://www.faa.gov/air_traffic/flight_info/aeronav/procedures/application/?event=procedure.results&tab=charts&nasrId=1L7#searchResultsTop

(The "Email FAA" button next to the procedure name)

 

[midlifeflyer]

I cannot find a reason these shouldn't be IAFs.

Your best bet is to contact the FAA TERPS office and ask the same question. As this procedure is also being amended (as noted above), it would be a good opportunity to have some input into the amendment.

https://www.faa.gov/air_traffic/flight_info/aeronav/procedures/application/?event=procedure.results&tab=charts&nasrId=1L7#searchResultsTop

(The "Email FAA" button next to the procedure name)

I did that about an hour ago. One of these days they are going to tell me to just go away.

 

[Palmpilot]

My speculation:

The feeder routes are marked with minimum altitudes, not mandatory altitudes. Meanwhile, the HILPT markings include a maximum altitude of 12000, and a pilot entering it at that altitude could reasonably want to use the HILPT to lose the extra altitude. NoPT markings on the transitions would prohibit that for pilots entering via those transitions.

 

[midlifeflyer]

My speculation:

The feeder routes are marked with minimum altitudes, not mandatory altitudes. Meanwhile, the HILPT markings include a maximum altitude of 12000, and a pilot entering it at that altitude could reasonably want to use the HILPT to lose the extra altitude. NoPT markings on the transitions would prohibit that for pilots entering via those transitions.

Isn’t that true of most transition routes - at or above rather than mandatory?

(The maximum altitude at holds is relatively new, before you could go up to 60,000 )

 

[flyingcheesehead]

The possibility of an error?

I had thought of that as well - I have gotten two plates corrected in the past. I just wanted to be sure I wasn't missing something completely dumb!

I can see a reason for the PT for the RASCO transition. That extra 500' brings the descent from UVSEH to the FAF to more than 3 degrees. But with a crossing at 9500 at UVSEH regardless of whether or not you do the PT, that reason would not apply.

My thoughts exactly. 9500 at UVSEH to 7700 at IKPUC is 295 ft/nm, shallower than a standard 3º glidepath. But even starting from 10,000 at UVSEH it's only 377 ft/nm or 3.56º which is manageable and I'm pretty sure within TERPS requirements?

You CAN get lower — 7700 MSL right after crossing UVCEH if you go straight-in, but you're aimed right for a 7500 MSL peak. At high IAS and turn radius you're possibly going to get too close for TERPs comfort, imo. TERPs might assume a random pilot could fly over the waypoint and descend immediately.

No, what I mean is that you can't get lower in the hold. Minimum altitude in the hold is 9500. So what is the hold doing for you?

I cannot find a reason these shouldn't be IAFs.

Your best bet is to contact the FAA TERPS office and ask the same question. As this procedure is also being amended (as noted above), it would be a good opportunity to have some input into the amendment.

Likewise, and wilco. I've gotten a couple of plates fixed in the past, and I was VERY impressed with the responsiveness of the FAA folks.

My speculation:

The feeder routes are marked with minimum altitudes, not mandatory altitudes. Meanwhile, the HILPT markings include a maximum altitude of 12000, and a pilot entering it at that altitude could reasonably want to use the HILPT to lose the extra altitude. NoPT markings on the transitions would prohibit that for pilots entering via those transitions.

Well, technically NOT having the NoPT prohibits pilots not flying the hold. In either case you can ask for a deviation (either asking to do a turn or more in the hold, or asking to be cleared straight in) but it seems that the default should be to just go straight in.

 

[John Collins]

My speculation:

The feeder routes are marked with minimum altitudes, not mandatory altitudes. Meanwhile, the HILPT markings include a maximum altitude of 12000, and a pilot entering it at that altitude could reasonably want to use the HILPT to lose the extra altitude. NoPT markings on the transitions would prohibit that for pilots entering via those transitions.

I doubt that. I think that it has more to do with the amount of airspace needed for a hold would interfere with KSJC and Moffit and/or the terrain if one placed an IAF/IF and a HILPT at DOCAL. I would guess that in many cases, one will just be vectored or cleared direct-to to the IF DOCAL to commence the approach. In a prior life or two ago, I used to fly in the area and had a Flight School at KSJC and KRHV in the 1970's. I learned to fly at KRHV. I recall Mt Umunhum poking through the overcast and always being cognizant of any extended silence when on vectors.

 

[flyingcheesehead]

I doubt that. I think that it has more to do with the amount of airspace needed for a hold would interfere with KSJC and Moffit and/or the terrain if one placed an IAF/IF and a HILPT at DOCAL. I would guess that in many cases, one will just be vectored or cleared direct-to to the IF DOCAL to commence the approach. In a prior life or two ago, I used to fly in the area and had a Flight School at KSJC and KRHV in the 1970's. I learned to fly at KRHV. I recall Mt Umunhum poking through the overcast and always being cognizant of any extended silence when on vectors.

Not sure how we're talking about SoCal now? This is into 1L7, Escalante, Utah.

 

[midlifeflyer]

I doubt that. I think that it has more to do with the amount of airspace needed for a hold would interfere with KSJC and Moffit and/or the terrain if one placed an IAF/IF and a HILPT at DOCAL. I would guess that in many cases, one will just be vectored or cleared direct-to to the IF DOCAL to commence the approach. In a prior life or two ago, I used to fly in the area and had a Flight School at KSJC and KRHV in the 1970's. I learned to fly at KRHV. I recall Mt Umunhum poking through the overcast and always being cognizant of any extended silence when on vectors.

That’s true of the hold on the chart I posted as an example of other approaches, but that’s not the one under discussion.

 

[John Collins]

That’s true of the hold on the chart I posted as an example of other approaches, but that’s not the one under discussion.

That's what happens when you join a discussion in the middle using the New Posts function and start reading from there.

 

[midlifeflyer]

I did that about an hour ago. One of these days they are going to tell me to just go away.

The reply

Thank you for your inquiry. The RNAV (GPS) RWY 31 procedure is already scheduled for amendment with a publication date of 6-12-2025. The primary purpose for the amendment is to change the segments from RASCO and HASSL to "NoPT" initial segments. The 8260 series forms for the amendment should be available for review/comment on our IFP Gateway no later than 3-17-2025.​

 

[RussR]

My thoughts exactly. 9500 at UVSEH to 7700 at IKPUC is 295 ft/nm, shallower than a standard 3º glidepath. But even starting from 10,000 at UVSEH it's only 377 ft/nm or 3.56º which is manageable and I'm pretty sure within TERPS requirements?

I am rather embarrassed that I missed that. I must be slipping. The maximum descent gradient for the intermediate segment is 318 feet per nm. So 10000 at UVCEH exceeds that and would require the PT (i.e. it doesn't qualify for NoPT). It still doesn't exceed it with the 9500 from HASSL to UVCEH though, so at least that leg should be NoPT. I have no idea why it isn't.

 

[RussR]

The reply

Thank you for your inquiry. The RNAV (GPS) RWY 31 procedure is already scheduled for amendment with a publication date of 6-12-2025. The primary purpose for the amendment is to change the segments from RASCO and HASSL to "NoPT" initial segments. The 8260 series forms for the amendment should be available for review/comment on our IFP Gateway no later than 3-17-2025.​

Good stuff!

 

[flyingcheesehead]

The reply

Thank you for your inquiry. The RNAV (GPS) RWY 31 procedure is already scheduled for amendment with a publication date of 6-12-2025. The primary purpose for the amendment is to change the segments from RASCO and HASSL to "NoPT" initial segments. The 8260 series forms for the amendment should be available for review/comment on our IFP Gateway no later than 3-17-2025.​

I guess I wasn't the first one to wonder what was going on here! I still haven't gotten a response to my inquiry, thanks for posting yours.

I am rather embarrassed that I missed that. I must be slipping. The maximum descent gradient for the intermediate segment is 318 feet per nm. So 10000 at UVCEH exceeds that and would require the PT (i.e. it doesn't qualify for NoPT). It still doesn't exceed it with the 9500 from HASSL to UVCEH though, so at least that leg should be NoPT. I have no idea why it isn't.

Interesting... I wonder if they're amending the altitude on the RASCO leg in the new version, since it sounds like they're going to make it NoPT?

 

[Palmpilot]

Isn’t that true of most transition routes - at or above rather than mandatory?

I think you're right.

(The maximum altitude at holds is relatively new, before you could go up to 60,000 )

I think the 12000 foot maximum altitude on the one at Escalante might be due to the proximity of V208, which has an MEA of 14000. With the outbound leg being seven NM long, and whatever the width of the airway is at that altitude, it looks like there could be a potential for loss of separation otherwise.

View attachment 133799

The highlighted areas in that chart are part of the approach, not transition routes.

 

[Palmpilot]

I doubt that. I think that it has more to do with the amount of airspace needed for a hold would interfere with KSJC and Moffit and/or the terrain if one placed an IAF/IF and a HILPT at DOCAL. I would guess that in many cases, one will just be vectored or cleared direct-to to the IF DOCAL to commence the approach. In a prior life or two ago, I used to fly in the area and had a Flight School at KSJC and KRHV in the 1970's. I learned to fly at KRHV. I recall Mt Umunhum poking through the overcast and always being cognizant of any extended silence when on vectors.

I was talking about the approach at Escalante, not the one at Palo Alto.

 

[Palmpilot]

Not sure how we're talking about SoCal now? This is into 1L7, Escalante, Utah.

Same here, except Palo Alto is Norcal, not Socal.

 

[midlifeflyer]

The highlighted areas in that chart are part of the approach, not transition routes

Either way, the charted altitudes are at or above so I don’t see a real distinction. I’m sure we can find an example you like better

 

[RussR]

I guess I wasn't the first one to wonder what was going on here! I still haven't gotten a response to my inquiry, thanks for posting yours.

Interesting... I wonder if they're amending the altitude on the RASCO leg in the new version, since it sounds like they're going to make it NoPT?

They would have to do that, or move UVCEH further to the SE (to make the segment longer).

 

[RussR]

(The maximum altitude at holds is relatively new, before you could go up to 60,000 )

I think the 12000 foot maximum altitude on the one at Escalante might be due to the proximity of V208, which has an MEA of 14000. With the outbound leg being seven NM long, and whatever the width of the airway is at that altitude, it looks like there could be a potential for loss of separation otherwise.

Holds always had a maximum altitude, it's just it was never included on the chart. It was, however, documented on the Form 8260-2 for the intersection/waypoint. There was just never a requirement to chart it. The maximum altitude would almost 100% of the time NOT be established through any real analysis, since after all, it wasn't charted anyway. If you look at 8260-2's, you'll see a lot of max altitudes of 17,500, just because that seems like a good maximum. Or you will see cases where the max is a few thousand feet higher than the minimum - the idea here being to give ATC a few different altitudes to hold airplanes at if they needed it. But again, that's about the most amount of analysis that went into it. Nearby airways and such aren't typically considered. Restricted airspace, though, was/is.

There are and were always rare cases where you could hold at, say, 6000 but not at 7000 - because above 6000 the max holding airspeed goes from 200 to 230 kias, and so the protected area gets larger. And that larger area now includes a nearby mountain. So in that case you would definitely have a maximum holding altitude of 6000. But again, max holding altitudes were not charted, so how was a pilot to know?

As with most things, this didn't cause a problem until it actually did. The perfect example was at Alamosa, CO (ALS), where holding higher than 12000 WAS a problem, since to get there you had to come over high terrain. NBAA brought this up to the Aeronautical Charting Forum and that discussion resulted in the current charting standard. You can read the whole minutes of the discussion here:

https://www.faa.gov/air_traffic/flight_info/aeronav/acf/media/RDs/15-02-297_Charting_HILPT_Max_Holding_ALT.pdf

 

[midlifeflyer]

The maximum altitude would almost 100% of the time NOT be established through any real analysis, since after all, it wasn't charted anyway

And it’s hard to hit terrain or an obstruction up there.

Joking aside, I’m familiar with that Charting Forum discussion.

 

[Palmpilot]

Either way, the charted altitudes are at or above so I don’t see a real distinction. I’m sure we can find an example you like better

I don't think we actually disagree on anything.

 

[midlifeflyer]

I don't think we actually disagree on anything.

Neither do I.