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Offset APP visual to final

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Offset APP visual to final

Old 11th Apr 2021, 08:15
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Offset APP visual to final

When can we align the aircraft visually on an OFF-SET ILS? After the FAP? Only at minima?

Same question for a NPA (VOR, RNAV...) ?

Like to find official references for both EASA OPS and FAR if different.

I understand the difference when flying SOIA / PRM approaches in places like SFO, where keeping the off-set needs to be done for lateral separation with the other aircraft. On approaches like JFK VOR 22L, On the other hand I’ve heard ATC yelling at crews when they would align just below 1000ft...

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Old 11th Apr 2021, 12:10
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No idea where to look for that. Some of the VOL x from 8186 series will have notes on the essential geometry.

The present company SOP say at 100' above minima but also have +100' DDA policy. The endresult is very reasonable in VMC.

Chart, courtesy of Lido Lufthansa Systems.


With 1000' AFE point around 3.8D JFK, one could imagine the ground track vector projection causing havoc onthe controller screens as the airplane rolls westward for the centerline.

In a similar fashion, one cannot blame them for expecting the traffic to treat an "on-procedure" WPT like CEMUG as a fly-over. Probably why it's there in the first place, 740' AFE

Last edited by FlightDetent; 11th Apr 2021 at 12:20.
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Old 11th Apr 2021, 14:18
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I havenít thought about that in a while. FAA AIM 5-4-16 (g) (4) would suggest the MAP. Happy to be corrected on that though. Perhaps aterpster can provide a better reference.
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Old 11th Apr 2021, 14:39
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Originally Posted by EK380 View Post
When can we align the aircraft visually on an OFF-SET ILS? After the FAP? Only at minima?
Same question for a NPA (VOR, RNAV...) ?
This same question was asked in 2010. See PPruNe 2010
Aterpster gave a good reply post # 18.

Google "JFK Airport Committee New York Community Aviation Roundtable" j and see RNAV GPS X Runway 22L Procedure.
There is no reason to offset that RNAV Approach - unless it is for noise. (The straight in ILS has no terrain problem).

If you are cleared for an off set Approach and become visual early then I suggest you ask ATC if you may continue visually - else they will expect you to follow the published track for Noise reasons.
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Old 11th Apr 2021, 16:39
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Nantes LFRS on 21 has an offset RNP approach. There is a note not to line up with the centreline before 1nm from the MAP, which is 2nm from the displaced threshold. This is due to a large tower block that was allowed to be built in the city on the extended centreline .
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Old 11th Apr 2021, 19:54
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I was always told the reason for the 22L offset/preference from the ILS when they are doing Canarsie/VOR 22L ops is for separation from LGA traffic. No authoritative source mind, just word on the street when I was flying long haul. I always enjoyed the 22L VOR for many reasons, and would generally line up below 1000’. JFK and EWR both offered a bit of fun flying in a heavy.
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Old 11th Apr 2021, 20:54
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If you’re cleared for the offset approach you fly the off set approach as published. There’s no “lining up early” you just fly what’s depicted. At some point the offset intercepts the three degree glide path to the runway and then you line up. At KORD if you line up early when cleared the ILS Y 10R, you’ll get, at minimum, an earful from the from the controller.

Like Goldenrivett said, if you want to fly the visual ask for it.



Order 8260.3C Appendix E






”1. Stabilized approach point. This is a design point along the extended centerline of the intended landing runway on the glide slope/glidepath at 500 feet above the runway threshold elevation. It is used to establish a sufficient distance along the extended runway centerline for the visual maneuver after the offset course approach DA to permit the pilots to conform to approved, stabilized approach criteria. The stabilized approach point is not published on the IAP”

https://www.faa.gov/documentLibrary/...3C.pdf#page482
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Old 15th Apr 2021, 11:07
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Thanks for your reply. My question is related to non-SOIA or PRM approaches, so the info doesn’t seem to be applicable.
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Old 16th Jun 2022, 00:06
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Hello, I have the same question..
Yesterday RNAV X 22L JFK we decided to start the lining up at around 1000'.
We were aware that the OFST is for noise but also our company is very strict on stab. criteria so...we mixed the two restrictions and it ended up with 1000'..
Did you find any "official" answer?

Thanks
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Old 16th Jun 2022, 05:13
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I think the thread quickly crystalized into:

An instrument procedure is to be flown as published. To this no more guidance is necessary.

Explanations, perhaps. What do you hope to find in that 'official' answer. (note the indefinite article at the start of the above sentence). Honest question.


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Old 16th Jun 2022, 12:24
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DTW has been doing ILS Y 22R lately with its 2.5deg offset. It's always VFR when they assign it, so I line up when it TLARs, usually 800-1000AGL.
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Old 16th Jun 2022, 14:29
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You are not confusing VFR for VMC, are you?
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Old 16th Jun 2022, 18:25
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Americans tend to say VFR (conditions) for what we call VMC.
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Old 17th Jun 2022, 10:40
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We do back home as well. The other usual suspect on CPL level is thinking visual approach is VFR.

This thread reinforced that visual manoeuvring is a part of the IFR procedure (*), a conclusion not possible with a lazy tongue.

(*) circumstantial evidence by NYC ATS.
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Old 16th Jul 2022, 08:18
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I have the same question as well, but I havenít found anything on my poor research.
I was flying to TIA RWY35 and we knew it was offset , on my opinion I said to stay on the procedure cause there was mountains bellow us on the path. But my cap. Told me we are visual you can disregard the offset and fly to the touch down zone and disregard the lateral and vertical FD. In fact we reset it. And he said Iíll cancel the glide slope warnings. So did I to be honest .there was no issue , we were visual. But how legal or letís say appropriate is that?
I guess the offset procedure is there for a reason?
Should we had asked for visual?
If you decide to stay in the approach,When does the allingment should start? At minimums?

I know I am such a company guy 🤓🤓
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Old 16th Jul 2022, 14:37
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As always, it works until one day it does not.

The heated discussion above was not because someone drifted (ATC told them off) but because others insisted it was their rightful choice to do so.

By the sound of your explanation / question alone, you are not on the dark side. Stay vigilant.

Post the chart and while at it include Tivat too, can get educative.


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Old 21st Jul 2022, 04:52
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There's a really important lesson in all of this, offsets, and the visual segment of a non precision approach have to be thoroughly briefed, and there's no universal answer that fits every approach... Here's a few charts as discussion points:

IliasP, here is Tirana:

So, the offset really isn't huge in terms of direction, but the sideways displacement is more of an issue. It's perfectly fine to fly on the radial until hitting the minimums, you'll still have enough distance to correct. However, when I want to deviate from such a procedure early, even if its severe VMC, I still let tower know we have the runway in sight and we would like to continue visually, just to keep everybody on the same page.


TIA VOR 35

DLM RNP 19
So, here is Dalaman - and this is an example where you definitely shouldn't stay on the approach path until the MAPt if you're intending to land if you can help it, the offset is 15 degrees, and you will reach minimums three miles out - a nice distance to swing onto the centerline. Flying on the lateral path until the MAP reduces this alignment distance to 0.8 NM, so you'll be at perhaps 300 feet at this point. Why on earth they designed this approach that way is beyond me, there are no close-in obstacles on the centerline, and obviously they could have aligned the final part of the approach (at least after the terrain at BS116) with the runway if they wanted to. But alas.


TIV LOC Z 32
And for FlightDetent, here's Tivat - thankfully a clear case, it's charted with a visual segment, and the 20 degree offset and the terrain on the north eastern side doesn't leave you any room to turn onto final early. You probably won't be wings level by 500ft, 300ft is realistic.

Oh, and I'd just like to rant about the IAN feature on the 737s and now the 787 as well - there really should be an option to disable the "faux-ILS" indications on the PFD (apart from selecting an ILS frequency on the Nav radios), on offset approaches they are more distracting than helpful... I've had a first officer call LOCALISER repeatedly after I aligned with the centerline at DLM after the RNP 19 approach, bless him

Last edited by STBYRUD; 22nd Jul 2022 at 04:51.
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Old 21st Jul 2022, 05:42
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Perfect. Bullet points:

MAPt being on the centerline does not always help, especially as RNAV or even VOR (see THR at TIA) can be too close. This gives proper credibilit to the 'early align' voices.

Tivat has a visual manouvering segment published. Different animal, tame one.

Procedure designers seem to take funny choices. Don't expect a righteous, supreme court approved solution to work at all times.

Jeppesens still fails to provide runway heading on approach chars.

Brief. Not before you understand. Brief. Not the paper, your trajectory. Brief. The other pilots needs to know your thoughts in advance to save the day once you drift from the agreed plan.

Great choice of the examples, I messed up all three of them (mostly for reasons beyond the topic) Does Sitia look any interesting (no access to charts)?

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Old 21st Jul 2022, 15:36
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Dalaman is an interesting one. The issue is as much vertical as horizontal though - I have done it at various altitudes but the big issue is that at the typical high ISA deviations in summer you will see 4W on the PAPIs and have to plan and brief how you will correct the approach path. As long as you can maintain visual obstacle separation when and how you do it is surely up to you within any limits placed on you on the plate and in your ops manual.

The ability to identify these issues in advance and will plan for them is a key command skill. Issues like the IAN or VDEV in the bus being wrong once off the instrument approach are less likely to confuse your oppo if you have briefed what you are going to do and what indications you expect visually and on the cockpit instruments. However, as always experience is a wonderful thing, and asking colleagues is generally as if not more valuable than whatís written formally.
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