Approach Plate Question - ILS 32 at SBY

TMetzinger

Final Approach
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Display name:
Tim
Crossposted from the DC Pilots mailing list:

Good day, everyone:

I was just studying the ILS 32 approach plate for Salisbury, which I have flown many times.
http://download.aopa.org/ustprocs/20090115/NE-3/sby_ils_or_loc_rwy_32.pdf

I can only find one IAF on the plate - the Snow Hill VOR. However, there is a "holding pattern" at COLBE depicted on the elevation diagram and a grey arrow from the SBY VOR (2000 to COLBE 140 degrees) which looks like a feeder to COLBE. (The missed is a hold at COLBE).

The transition from Snow Hill is labelled "NO PT". Should COLBE be an IAF?
If not, what is the purpose of the grey arrow pointing to COLBE from SBY and the holding pattern on the elevation view ?

Mark




Now, I think the gray arrow is to identify COLBE, but don't know why the holding pattern is identified on the profile view.
 
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Now, I think the gray arrow is to identify COLBE, but don't know why the holding pattern is identified on the profile view.
The only reason I can think of is to allow retrying the approach after a miss, since that holding pattern is the one identified on the missed approach procedure. It would make sense for that to be there if the approach was started from the SBY VOTRAC, but if that was the case, SBY would be identified as an IAF as well.

The gray arrow does allow identifying COLBE without a DME.
 
And while we're in the neighborhood, what's the significance of the "LR-148"?
-harry
 
And while we're in the neighborhood, what's the significance of the "LR-148"?
-harry
I think that's a hint for the transition from Snow Hill since there's no PT. I don't think I've seen an LR on this type of transition before, but it's helpful.
 
And while we're in the neighborhood, what's the significance of the "LR-148"?
-harry

Its been a long time since using NOS charts. I don't have a Jepp version to reference against at home. I believe that LR-148 is the lead in radial where you would want to begin your left turn to capture the localizer. R-140 is just too close to the localizer to to make that 90 degrees or course change and not over shoot the localizer.
 
The only reason I can think of is to allow retrying the approach after a miss, since that holding pattern is the one identified on the missed approach procedure. It would make sense for that to be there if the approach was started from the SBY VOTRAC, but if that was the case, SBY would be identified as an IAF as well.

The gray arrow does allow identifying COLBE without a DME.

It looks to me like there should be at least one other IAF on the chart, either SBY, COLBE, or both. The hold is depicted with bold lines which is supposed to mean it's part of the approach (a HILPT), not just the missed hold. The presence of the HILPT in the profile view also indicates that it isn't just for the miss procedure. The gray arrow from SBY is a transition which sure makes it look like COLBE was/is an IAF. If this particular guidance was only part of the missed approach it would be a dotted line and if SBY was an IAF I'd think it would be bold.

I don't buy the notion that the SBY140 transition and HILPT is there so you can re-fly the approach after a miss. AFaIK, flying an approach is supposed to be the same whether you just arrived or were in the missed hold.

BTW Jay, I couldn't tell if the "gray arrow" in your last sentence referred to the SWL R-020 line or the SBY 140 transition being discussed. Obviously the latter can't be used in lieu of DME to identify COLBE (but the SWL040 radial can).

I'd say this plate needs to be corrected, either by replacing the bold hold HILPT with a dotted (missed) hold, or adding COLBE as an IAF.
 
Perhaps there was an NDB at COLBE once and it WAS an IAF, and when they decommissioned it they only did a partial job on correcting the plate.
 
WAG based on (a) the fact that the profile view shows a 1-minute HILPT at COLBE and (2) the plan view shows a 2000' transition from Salisbury: SBY is an IAF and they forgot to put the "IAF" on the chart.

LR-148 is a lead radial for the sharp left turn on the Snow Hill transition.
 
It looks to me like there should be at least one other IAF on the chart, either SBY, COLBE, or both. The hold is depicted with bold lines which is supposed to mean it's part of the approach (a HILPT), not just the missed hold. The presence of the HILPT in the profile view also indicates that it isn't just for the miss procedure. The gray arrow from SBY is a transition which sure makes it look like COLBE was/is an IAF. If this particular guidance was only part of the missed approach it would be a dotted line and if SBY was an IAF I'd think it would be bold.
Hm. COLBE looks like it's the right distance out for an LOM...maybe there was one there that got decommissioned, as Tim suggested. That would make it appropriate for an IAF. It wouldn't qualify now, though, right? since it's only identifiable as an intersection.

BTW Jay, I couldn't tell if the "gray arrow" in your last sentence referred to the SWL R-020 line or the SBY 140 transition being discussed. Obviously the latter can't be used in lieu of DME to identify COLBE (but the SWL040 radial can).
Yeah, I was referring to the SWL 040 radial. Should have made that clearer. For that matter, why isn't COLBE on the SBY 139 radial, instead of the 140? Seems like you'd come out of the hold slightly off the localizer. This, too, suggests that there was once an LOM there.

I'd say this plate needs to be corrected, either by replacing the bold hold HILPT with a dotted (missed) hold, or adding COLBE as an IAF.
Can COLBE be an IAF, though? How would you navigate to it without going to SBY or SWL first? (Assuming non-RNAV navigation capabilities.) I'd expect SBY to be the added IAF.
 
Big oops in the recharting of this approach since the decommissioning of the COLBE NDB and LOM, which used to be an IAF. Since there's no more way to proceed direct to COLBE other than by GPS, the approach was changed. I think they just plain forgot to leave COLBE INT as an IAF, because operationally, they're running folks in to SBY VOR and clearing them for the approach (out the SBY 140R to COLBE INT, then HPILPT and right back up the LOC). In addition, GPS-equipped aircraft are still being cleared direct COLBE, and executing from there. Time to get my friends in the procedures world involved, so stand by...

As for the lead radial, if you're coming in on the Snow Hill transition and going fast enough/with a big wind from the S/SW, you have to start the left turn onto the localizer before the LOC needle starts to swing in or you'll overshoot. Having the SBY 148 radial dialed in allows you to start the intercept turn with the LOC still pegged and then complete it on the LOC once the LOC starts to swing.

And yeah, since that's where I live, I've flown this one about a zillion times.
 
Its been a long time since using NOS charts. I don't have a Jepp version to reference against at home.
Here's the Jepp chart. Hmmm... COLBE is an IAF on this chart.
 

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That chart is out of date -- COLBE NDB and OM were decommissioned months ago.
It's not out of date. It's from the current database on Jeppview.
 

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Hm. COLBE looks like it's the right distance out for an LOM...maybe there was one there that got decommissioned, as Tim suggested. That would make it appropriate for an IAF. It wouldn't qualify now, though, right? since it's only identifiable as an intersection.

I don't believe that an IAF has to be based on a ground station for a ILS approach. I've definitely seen some that were demarked by an outer marker only and that's not a navigable target. But it still wouldn't surprise me that the IAF got dropped (inadvertently) when a locator was decommissioned.

For that matter, why isn't COLBE on the SBY 139 radial, instead of the 140? Seems like you'd come out of the hold slightly off the localizer. This, too, suggests that there was once an LOM there.

Two reasons. One is that VOR radials can be up to 10 degrees misaligned with magnetic courses and the other is that the VOR is offset from the LOC centerline. In this case I assume that SBY-R140 intersects the LOC at the fix or is at least closer to that fix than R-139.

Can COLBE be an IAF, though? How would you navigate to it without going to SBY or SWL first? (Assuming non-RNAV navigation capabilities.) I'd expect SBY to be the added IAF.

It's hard to tell from the approach chart but there could be other ways to get to COLBE including radar plus these days it seems that they are putting IAFs on approaches that can only be reached via RNAV/GPS. As long as there are other ways to fly the approach that don't require GPS, or radar there's no need to put such a limitation on the chart, it's up to the pilot to determine whether or not he can get there on his own.
 
Hmm the date on the chart itself is 16 Nov 2007. Maybe Jepp is out of date.
That was the date of the last revision of that chart. They don't update the dates every time a new database is released. It could be that the database is wrong but it's definitely the one I downloaded a half hour ago.
 
I don't believe that an IAF has to be based on a ground station for a ILS approach. I've definitely seen some that were demarked by an outer marker only and that's not a navigable target. But it still wouldn't surprise me that the IAF got dropped (inadvertently) when a locator was decommissioned.



Two reasons. One is that VOR radials can be up to 10 degrees misaligned with magnetic courses and the other is that the VOR is offset from the LOC centerline. In this case I assume that SBY-R140 intersects the LOC at the fix or is at least closer to that fix than R-139.



It's hard to tell from the approach chart but there could be other ways to get to COLBE including radar plus these days it seems that they are putting IAFs on approaches that can only be reached via RNAV/GPS. As long as there are other ways to fly the approach that don't require GPS, or radar there's no need to put such a limitation on the chart, it's up to the pilot to determine whether or not he can get there on his own.
It SHOULD still be marked as an IAF, though, no?
 
Out of curiosity I looked up the Jepp chart notams for this procedure. The MSA is now based on the SBY VOR instead of the SB LOM which would make sense if the LOM is decomissioned.
 

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Well, one of them is wrong, and since Ron operates there, my money is that Jepp hasn't updated the chart.

Ahh but Tim therein lies the million dollar question! When was the last time Ron was updated. Bet his wife would know!:rolleyes:
 
Well, one of them is wrong, and since Ron operates there, my money is that Jepp hasn't updated the chart.

Jepp only updates what it receives from the government and not just the US government. We can't rely on a local pilots knowledge when operating. We have to be able to trust that everything is functioning other than what has been notamed out if it is included in a current chart. Some charts are not update for years at a time. If nothing changes, then the chart doesn't need to be updated.

With more advanced aircraft systems the only thing that we really need to have functioning is an ILS. On some flight management systems you don't even need the actual ILS. With approaches with LPV minimums you don't need any ground based navaids at all.
 
It's not out of date. It's from the current database on Jeppview.
Not arguing with the latter, but it is out of date because those two navaids were decommissioned months ago, and the procedure officially changed by the FAA on Day 297 of 2008 (October 23 or so). If that's Jepp's current chart, they missed the change.
 
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(2) the plan view shows a 2000' transition from Salisbury: SBY is an IAF and they forgot to put the "IAF" on the chart.

They forgot IAF on the chart, but it's COLBE that should be marked as an IAF, not SBY. If SBY was supposed to be an IAF, the 140 radial would be marked as a procedure track, not a transition.

I don't believe that an IAF has to be based on a ground station for a ILS approach. I've definitely seen some that were demarked by an outer marker only and that's not a navigable target.

ALL of our ILS FAF's at KMSN are also IAF's, and NONE of them are based on ground stations any longer, even the markers were decommissioned. I think the trick is that transition routes from an actual ground station are required.
 
Current version of JEPP:

COLBE is an IAF.
 

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Current version of JEPP:

COLBE is an IAF.

The LOM is still on that chart. AFaIK it was decommissioned a while ago. Looks like both plates are in error (Jepp and NACO).
 
I just downloaded the Feb 12 version of the Jepp plates and the ILS plate is still the Nov 07 version.

I was able to find the attached. It looks like the HILPT should have been removed, but I'm new at reading those things. Edit: the HILPT should be removed and depicted as the missed approach hold.

Joe

ps: Some of these documents are available at http://avn.faa.gov/acifp.asp seems like that website has (fairly) new modifications only.
 

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They forgot IAF on the chart, but it's COLBE that should be marked as an IAF, not SBY. If SBY was supposed to be an IAF, the 140 radial would be marked as a procedure track, not a transition.
Okkay...so you get to COLBE from the enroute structure by flying to SBY, then tracking outbound on the 140 radial?
 
Okkay...so you get to COLBE from the enroute structure by flying to SBY, then tracking outbound on the 140 radial?

COLBE
Navaid radial/DME: SBY r139.79/6.37

That's right, Jay. The transition is outbound on a 140-degree heading, tracking the r140 of SBY, to either/both SBY DME 6.4 / SQL r020 radial (more is better!).
 
If the Jepp chart still shows the Colbe NDB and the outer marker, it's out of date because the plug was permanently pulled on both last fall. In fact, since NACO has published all new charts without them, their decommissioning is not even a NOTAM any more. Somebody needs to tell Jepp that.
 
I was able to find the attached. It looks like the HILPT should have been removed, but I'm new at reading those things. Edit: the HILPT should be removed and depicted as the missed approach hold.

Joe
Joe,
I'm no expert, but it looks to me like COLBE is correctly depicted as a HILPT (see thumbnail).

As previously mentioned, the "IAF" was inadvertently removed when the NDB was decommissioned.
 

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Still waiting for my pal in the FAA procedures world to reply. There's no doubt that the NACO chart is wrong as printed, but there's no way to know exactly what's right until we hear back.
 
Joe,
I'm no expert, but it looks to me like COLBE is correctly depicted as a HILPT (see thumbnail).

As previously mentioned, the "IAF" was inadvertently removed when the NDB was decommissioned.
I'm just getting started reading these things. I was looking at the Terminal Routes (attached). By listing the SBY VOR but not the COLBE intersection, I'm confused.

attachment.php


It does seem clear that there is an inconsistency and an IAP is missing, or the HILPT should be deleted.

Still waiting for my pal in the FAA procedures world to reply. There's no doubt that the NACO chart is wrong as printed, but there's no way to know exactly what's right until we hear back.
I can't wait for the real answer to the puzzle.

Joe
 

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Okkay...so you get to COLBE from the enroute structure by flying to SBY, then tracking outbound on the 140 radial?

Bingo, Jay.

IAF's are not always part of the enroute structure, even if they *are* navaids and not just intersections. The plate will depict transition routes from selected fixes in the enroute structure to IAF's in many cases.

For an interesting example, check out the VOR or GPS RWY 4 approach into KRAC. The Horlick (HRK) VOR on the field at KRAC is not part of the enroute structure. In this particular case, the only way to get to this approach without a GPS is to fly to the PETTY intersection (which is the intersection of V7, V170, and V216). From there, you follow the transition route which leads from PETTY to the HRK VOR on the 066 radial (246 TO, in this case) and then from HRK on the 218 radial to SUZAN intersection, the IAF.

So, an IAF isn't necessarily going to be a navaid, and a navaid isn't necessarily going to be an IAF. This approach is kind of an interesting example of that because it leaves the enroute structure from an intersection, crosses a navaid on the transition to an IAF that's another intersection.

PS: Just because *someone's* gonna say it, I'll get it over with: "Huh huh... He said 'Horlick.'" ;)
 
Guess they read my email:
!FDC 9/5543 SBY FI/P SALISBURY-OCEAN CITY WICOMICO RGNL, SALISBURY, MD. ILS OR LOC RWY 32, AMDT 6A. CORRECT PLANVIEW: ADD TEXT IAF TO COLBE INT.
 
I think the purpose of the LR-148 is to keep the pilot out-bound on SWL-046 from intercepting a possible side-lobe prior to getting to the main beam.
 
I think the purpose of the LR-148 is to keep the pilot out-bound on SWL-046 from intercepting a possible side-lobe prior to getting to the main beam.
No, it's just a lead radial warning you to start turning now if you don't want to overshoot the localizer course. If you wait for the localizer needle to start swinging, you'll blow through it unless there's a howling wind from the northeast or you're flying a Cub...slowly. Do the math if you want the proof -- compare 3 degrees at 12 miles to the turning radius of a plane making a standard rate turn at 90-200 knots.
 
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