Intercept Loc Outbound

[hiren.bhingradia]

Whats the exact procedure for Intercept LOC outbound on ILS chart ? ( not Back course chart ) .:oh:

Select NAV ( for Intercept Loc outbound ) with needle showing reverse sensing ? with outbount course or final course .
or
BACK (for Back course ) with needle showing correct sensing ? with outbount course or final course.

[TyroPicard]

Posting the a/c type might help?

[BOAC]

I cannot help with your type (Atr 72-500??):cool: but generally it will depend on which instrument you are using.

If you are merely using an ILS indicator display, you would need either a 'Back Course' switch or to reverse what you do. This is because the instrument only knows whether you are left or right of the beam.

If you have the ILS displayed on an HSI, the HSI 'knows' the direction of the beam you are trying to follow (you set it in a window somewhere) and thus will know how to display the deviation so it is displayed correctly.

Edited to add 'Inbound course' set on the HSI

[tg743]

HSI to inbound course and fly the intercept and tracking in HDG mode. Thats my way..
My flying has me intercepting loc outbound atleast every third flight. This works perfect

[hiren.bhingradia]

For ATR 72-500 & inst EHSI ,
Arm Back course for ILS chart is it correct procedure(we have to intercept LOC outbound only) ? because
for Back course there is special chart like ILS ??( INDIA we don't have )

[BOAC]

Sorry, hiren - I don't understand what you are saying there.

[CptRegionalJet]

Never heard of such a "departure".Can you name an airport or post a chart,please?Only thing i know of is using the DME of the ILS for a distance to turn after departure(like @MRS)

[d105]

I don't really get it either.

Are we talking about the classic outbound radial followed by a left or right turn to intercept the localizer? In which case you would have the VOR tuned to track the radial outbound until a certain DME. Afterwards you turn in and switch to the ILS. Use the ADF if co-located to adjust your turning rate towards the localizer.

[hiren.bhingradia]

http://images.orkut.com/orkut/photos/OgAAAB98wCPUV8bikBDh6le3IXJCij-Z-ja11PITB8ZeES2PN8a41EM1_pFWClWO_QezQHJzIkJnl8Ba5s52HNUAgO0Am 1T1ULFxykwog51luTU_uJmpttSTDk_d.jpghttp://images.orkut.com/orkut/photos/OgAAABrdgu9Mwvv2HTaZomdiUQOqzRnF_yqQEu4FAEXPAUpMrMVdJNvP0W_M g8hweSTS1_N2FJLeAPxggexsrqdcs3oAm1T1UBAkjvOOkgdOZ3Aovq_ygOXL yrrD.jpg

[hiren.bhingradia]

Sorry for wearied question ?

Actually asked to me for my ATPL viva ?
How you intercept Loc outbound ?

@ d105 - you got my question bit - after tracking outbound VOR radial we swich to ILS freq after that the question is - We go for Back course or arm Nav mode to intercept Loc outbound for this chart ?

[SNS3Guppy]

Hiren,

You appear to be asking about flying to the VOR to begin the procedure, then flying outbound for the procedure turn. You didn't provide the entire chart, but if this is what you're describing, then your actions are fairly straight-forward.

You said you're using an EHSI display. With this in mind, set the inbound course. Forget selecting back course, as it's irrelevant, in this case. Set the inbound course and fly it.

If you have an EHSI, set the inbound course regardless of whether you're flying the front or back course, and you'll always have normal sensing.

Someone had asked about flying a backcourse outbound for a departure. This does happen in the Aspen, Colorado (USA) departure.

http://www.fltplan8.com/AppCharts/GIFCHARTS/05889SARDD_0001.gif

[CptRegionalJet]

Thanks for the approach and departure chart....Interesting approach and departure:ooh:

[SNS3Guppy]

The departure is set up with a back course in order to provide normal sensing on the outbound course.

The airport has a localizer approach, using a different facility to the runway, but the back course beacon is set up for departure purposes.

You can see the relationship between the two facilities, geographically, as well as some of the surrounding terrain:

http://www.fltplan8.com/AppCharts/GIFCHARTS/05889LDE_0001.gif

[CptRegionalJet]

Not having this kind of thing here in europe,how would I interprete the note "back course has normal sensing"?:confused:
Would a false capture on one of the beams happen if a LOC mode is armed to early?

[Zeffy]

CptRegionalJet

To understand the "normal sensing" aspect, imagine that there is an ILS or LOC approach to Rwy 30 (again, imaginary) at Aspen.

You miss the approach and are required to track outbound on the back course. The "sensing" will be normal.

And I don't think it would be a good idea to use any lateral mode beyond HDG -- engineers who designed the avionics aren't likely to have contemplated a LOC signal growing wider in the direction of flight.

[BOAC]

Hmm! SN3 - I think you may well have blown poor Hiren's brains there! Not the ideal chart to try to 'help with'?

1) There is no 'back course ILS that I can see - in my book the labelling of the outbound loc is mis-named.
2) I assume the localiser on the I-PKN has reversed lobes?
3) If it was a 'back-course' localiser, there has to be a 300 inbound course localiser - there is not.

This is simply a 'fudged' localiser for tracking purposes, not a 'back course'.

Hiren - I think you have got yourself more than a little confused here. Looking at your post to d105:
"@ d105 - you got my question bit - after tracking outbound VOR radial we swich to ILS freq after that the question is - We go for Back course or arm Nav mode to intercept Loc outbound for this chart ? "

1) Whyare you trying to "intercept Loc outbound" when you have turned inbound?
2) Which chart are you talking about?

Let's just stick to your original question. Why not look at the chart for LFLB (Chambery) in the French Alps? Take Jeppesen plate 10-3 and you will see that you need to fly the ILS R18 northwards on departure. To do this you select the EHSI to 180 inbound localiser course. The EHSI then shows your position in relation to the localiser correctly. On the 737 standby horizon (which has localiser left/right only) you also need to select 'Back Course' to see the correct display.

Please note I have no idea what 'NAV' does in the ATR EHSI.!

I suggest you ignore the charts for Aspen!

Edited to add (after a glass of Shiraz:)) that if SN3 can produce a 300 inbound localiser procedure chart on the I-PKN I will accept is as a back-course....

[CptRegionalJet]

Zeffy,thanks for clearing things up a little...

[SNS3Guppy]

Hmm! SN3 - I think you may well have blown poor Hiren's brains there! Not the ideal chart to try to 'help with'?

I didn't post it for Hiren's benefit. CptRegionalJet suggested he hadn't heard of a departure using a back course, and that's why I posted the KASE SARDD ONE.

1) There is no 'back course ILS that I can see - in my book the labelling of the outbound loc is mis-named.
2) I assume the localiser on the I-PKN has reversed lobes?
3) If it was a 'back-course' localiser, there has to be a 300 inbound course localiser - there is not.

This is simply a 'fudged' localiser for tracking purposes, not a 'back course'.

Nope: it's a localizer back course. There's no front course.
1) It's not misnamed. It's a localizer back course, pure and simple. It's just used for the departure, rather than for an approach. As a localizer, it has a narrower signal for the departure, and is aimed at a mountain pass leading to LINDZ intersection.
2) No, I PKN is a back course. There's no front course. It's installed this way to provide normal sensing while flying outbound, as the I-PKN localizer back course is used for a departure, and the missed approach for the LOC/DME-E, and VOR/DME procedures.
3) There doesn't have to be a front course. It's a back course. It's stuck in the mountains. It isn't flown as a back course to the airport, and neither is the front course; it's located physically on the other side of a mountain from the Aspen airport; there are big rocks between the airport and the transmitter. It's oriented as it is, providing back course guidance to give normal sensing on the way out on the departure and missed approach procedures.

It is a localizer for tracking purposes, and not for approach purposes (other than the missed); it's in very mountainous terrain, and serves as relatively precise guidance through and over a mountain pass. It is, however, a localizer back course.

Hiren - I think you have got yourself more than a little confused here. Looking at your post to d105:
"@ d105 - you got my question bit - after tracking outbound VOR radial we swich to ILS freq after that the question is - We go for Back course or arm Nav mode to intercept Loc outbound for this chart ? "

1) Whyare you trying to "intercept Loc outbound" when you have turned inbound?
2) Which chart are you talking about?

I don't think Hiren has much instrument training, and is either a sim game player, or a new hire with very little training or experience. It appears that he doesn't understand his autopilot functions, and is attempting to work out how to set up the autopilot while flying the approach. He also doesn't appear to understand the basics of using an HSI.

He has stated that he's got an EHSI, and isn't sure how to follow it after flyin to the VOR, and intending to execute the approach. He needs to fly outbound for a procedure turn, and wants to know how to stay oriented.

Again, Hiren, set in the front course for the approach, and you've got normal sensing all the way through the procedure. No need to mess with a back course switch, and you won't have any reverse sensing. When you dial in the front course in the EHSI, your course needle going left will always mean you fly left. Your course needle going right will always mean you go right. No matter if you're flying toward the runway, or away from it. You get normal sensing all the time.

[ImbracableCrunk]

Aren't you guys making this entirely too complicated?

Flying a back-course outbound is the same as flying a front-course inbound. Nothing tricky. Arm LOC, and have the front-course dialed in.:ugh:

[BOAC]

I didn't post it for Hiren's benefit. - my mis-understanding - a function of the inevitable thread creep.

CptRegionalJet suggested he hadn't heard of a departure using a back course - LFLB R36 is a better one. tg743 doubtless knows others.

The concept of a 'back course' without a 'front course' is one I will pass on.:confused:
A bit like having a backing group with no 'star' up front or a back-up power supply with no primary. :)

[aterpster]

BOAC:

The concept of a 'back course' without a 'front course' is one I will pass on.http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/confused.gif
A bit like having a backing group with no 'star' up front or a back-up power supply with no primary

Your points would be well taken if the installation were for an approach procedure. But, this is a special case to provide correct sensing for missed approach and departure procedures. When this was installed, RNAV was a limited concept (pre-GPS) so there was no other way to get the course guidance needed to avoid the higher terrain to the southwest of the airport.

[PBL]

Cute SID. Glad I don't have to fly around there. :)

I am with BOAC on this one: the "back course" is misnamed.

A *course* is directional, both in common speech and in (European) aviation. Both a front course and a back course are flown *towards* the antenna, in the normal meaning of the terms. The non-directional concept can be denoted by the term "course line".

According to those meanings, the SARDD ONE SID requires that one fly the *reciprocal of a back course*.

But maybe for the FAA a "course" sometimes a course line, without direction. Who are we to argue (although we may smirk)? That means the two available courses (in the above meaning) would be called "back course outbound" and "back course inbound". Indeed, here is the quote from the AIM (at http://www.faa.gov/air_traffic/publications/atpubs/aim/Chap1/aim0101.html):

2. The approach course of the localizer is called the front course and is used with other functional parts, e.g., glide slope, marker beacons, etc. The localizer signal is transmitted at the far end of the runway. It is adjusted for a course width of (full scale fly-left to a full scale fly-right) of 700 feet at the runway threshold.

3. The course line along the extended centerline of a runway, in the opposite direction to the front course is called the back course.

So a "front course" is a course, but a "back course" is a course line, not a course. So be it.

This kind of mild confusion doesn't often matter for regular local airspace users, but such things do get one into grave difficulties sometimes. I just wrote a paper on critical verbal communication in major accidents (rail and air) for the Handbook of Technical Communication (ed. Gibbon and Mehler, Mouton-de Gruyter, Berlin, forthcoming 2011). The air accidents I consider are Cali and Überlingen.

PBL

[SNS3Guppy]

I am with BOAC on this one: the "back course" is misnamed.

Explain that to those who correctly named the facility per convention and in accordance with TERPS.

Both a front course and a back course are flown *towards* the antenna, in the normal meaning of the terms. The non-directional concept can be denoted by the term "course line".

According to those meanings, the SARDD ONE SID requires that one fly the *reciprocal of a back course*.

No, the SARDD ONE requires that one fly outbound on the backcourse.

I realize that you have a real thing for arguing, but you understand that you're arguing the official title of the components of the procedure, so designated per convention, appropriately according to the facility, by the people who designed the procedure. I really do believe that you'd argue that black is white just to make an argument.

Both a front course and a back course are flown *towards* the antenna, in the normal meaning of the terms. The non-directional concept can be denoted by the term "course line".

This kind of mild confusion doesn't often matter for regular local airspace users, but such things do get one into grave difficulties sometimes.

Not in this case. The facility is correctly named and identified. The procedure for it's use is clear and well known, and in full conformance with the prescribed terminal procedures criteria. There is nothing ambiguous about the procedure or it's naming convention, nor is there anything difficult, grave, or otherwise, regarding the procedure's use, the design or function of the facility, or it's name.

You're attempting to argue and be difficult where there is no argument, nor grave difficulty.

[aterpster]

The old time fixed card indicator. This is all still valid:

http://tinyurl.com/25urnpf

[PBL]

This kind of mild confusion doesn't often matter for regular local airspace users, but such things do get one into grave difficulties sometimes.

Not in this case. The facility is correctly named and identified. The procedure for it's use is clear and well known, and in full conformance with the prescribed terminal procedures criteria.

As I said, fine for regular local airspace users.

Check out the Cali situation, in which the ROZO ONE arrival was named after the endpoint, fully in accordance with local procedures and regulations. But it demonstrably confused the US pilots, who were apparently assuming that ROZO was the commencement of the arrival. And they didn't arrive. AG RVS - Comments on Confusing Conversation at Cali (http://www.rvs.uni-bielefeld.de/publications/Reports/cali-comment.html).

Or check out the GOL-Legacy collision, where ATC (and, apparently, almost the entire Brazilian public) was expecting Legacy to change Flight Level without a communication, because it had that change of FL on its flight plan. That's apparently what you do according to local procedure and regulation.

You're attempting to argue and be difficult where there is no argument, nor grave difficulty.

Well, I accept that you don't see one. But that's the thing with these matters. No one saw a problem at Cali, either. Neither did anyone see a problem with having another NDB with the same ID and FREQ 200nm east. I mean, why would you ever tune it in from so high up? But they did.

And no one in Brazil was apparently expecting Legacy to adhere to ICAO norms rather than local ones when radio contact was lost.

And we won't mention the problems US pilots have flying runway heading in the UK when instructed to do so by ATC. Or will we?

Language is a big deal.

PBL

[BOAC]

Well, hoping not to get dragged into yet another session of slanging, here!

Why on earth was the procedure not constructed on a 'front course' of 120? The g/a then back-tracks this localiser a 'course' set of 120, as in many other procedures. I am assuming, of course, that there is no requirement for a 'front course' of 300 in any procedures there, in which case I think this has all been made with unnecessarily complicated?

Apart from keeping everything 'standard', there is a distinct advantage in this solution, namely the course needs only to be twiddled from 148 to 120 for the g/a, instead of all the way round to 300. One less thing to do when surrounded by cumulo-granitus.
so there was no other way to get the course guidance needed to avoid the higher terrain to the southwest of the airport. - have I not just done exactly that? I am unconvinced that just because it 'fits' with some notion of naming in TERPS that it is correct!

[SR71]

I realize that you have a real thing for arguing, but you understand that you're arguing the official title of the components of the procedure, so designated per convention, appropriately according to the facility, by the people who designed the procedure. I really do believe that you'd argue that black is white just to make an argument.

One wonders how it was possible the Titanic ever sank?

;)

I think there is no provision for back-course approaches in the UK, and I have no experience whatsoever in these types of approaches even flying around Europe in the capacity I do, but the give away for me is the "NB" on the chart.

Surely an explicit acknowledgement by Jepperson that the chance of ambiguity exists?

Even then I still find the note ambiguous. Is it normal sensing when you've dialled up "300" or normal sensing when you've dialled up "120"?

Is that claim to "normality" contingent on the fact you've called it a "back-course"?

What does "normal" mean if this is a "non-normal" approach for you? I haven't flown a back-course approach in at least the last 4000...

And if the sensing depends on what instrumet you're using, the note isn't very helpful anyway....

The semantics is hugely important.

[aterpster]

PBL:

Well, I accept that you don't see one. But that's the thing with these matters. No one saw a problem at Cali, either. Neither did anyone see a problem with having another NDB with the same ID and FREQ 200nm east. I mean, why would you ever tune it in from so high up? But they did.

Those guys were both "radar babies" and "children of the magenta line."

First, they tried to get a short-cut in to a procedure in a mountainous area in a non-radar environment, and in South America no less. That flunks IFR Flying 101 right there.

Second, when the aircraft started its big wild-a** turn to try to go to the wrong beacon, a passing grade in IFR Flying 101 would required disconnecting LNAV and using the heading mode to get back on track now. Instead, they became passengers, continuing a wild spoiler-aided descent while letting mis-programmed LNAV take them to neverland.

It was a ground-based combined arrival/IAP procedure they were attempting to fly with RNAV. For those with clues in 1995, there would have been more than a modicum of wariness.

[aterpster]

BOAC:

- have I not just done exactly that? I am unconvinced that just because it 'fits' with some notion of naming in TERPS that it is correct!

No, you have not. You are presuming an HSI where the card is rotated (thus changing the orientation of the CDI) by changing the value in the course window; i.e., set the inbound front course to have to-the-needle sensing on a back course.

Fix cards cannot be rotated. That is the purpose of my illustration above. This installation at ASE was done many years ago, to accommodate the lowest common denominator. There was, and is, no "notion of naming in TERPs" that drove this installation.

[BOAC]

Fix cards cannot be rotated. That is the purpose of my illustration above.. - I think your picture is not one of those! It looks like a museum piece Narco OBS to me.

Quite honestly fiddling around to allow for fixed card aircraft is a waste of time! Anyone using it should be able to work out their displacement from a line or should not fly IFR. Otherwise how on earth would they cope with tracking a localiser outbound or track away from an NDB?

[aterpster]

BOAC:

- I think your picture is not one of those! It looks like a museum piece Narco OBS to me.

I wouldn't argue about its status as a museum piece. Nonetheless, it still meets specs and could be used today. My point in posting it was to show the blue-yellow markings below the course deviation indicator. The "twistable" analog course values at the bottom of the indicator is the selection made by the OBS knob. The OBS selection only affects VOR, not LOC. This indeed is a VOR/LOC navigation indicator with CDI, compliant scaling, OBS selector, and OBS indicator. In more modern displays, such as an HSI, the course selector serves both to position the card and when selected to a VOR facility, it also serves as an OBS.

The use of the blue-yellow indicator was quite common when I first got involved with instrument flying in 1957.

Quite honestly fiddling around to allow for fixed card aircraft is a waste of time! Anyone using it should be able to work out their displacement from a line or should not fly IFR. Otherwise how on earth would they cope with tracking a localiser outbound or track away from an NDB?

Perhaps it was all a waste of time. Unlike you I am open on that. I do know they could not achieve the clearance from very high terrain to the southwest for the missed approach procedures unless they used a localizer.

[Zeffy]

My point in posting it was to show the blue-yellow markings below the course deviation indicator.

Thread hijack alert.

Blue/Yellow LOC references were included in early jet transport avionics systems.

The FD mode selection and feedback loop were central to the investigation of a DC-9 accident at Boston July 1973 (http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR74-03.pdf).

In the report, one can find references to a "Blue Left" Sperry Flight Director mode:

http://i202.photobucket.com/albums/aa92/zeffy_bucket/BlueLeft.png

As aterpster has noted, the CDI is turned upside-down by an HSI to provide proper orientation for the crew.

The BC (nee "Blue Left") FD mode is necessary to obtain correct steering from the FD.

[SNS3Guppy]

And we won't mention the problems US pilots have flying runway heading in the UK when instructed to do so by ATC. Or will we?

We won't, because I've never found that to be the case. That is, where such isolated cases may exist, these are pilots failing to follow an established ATC direction, not a language ambiguity. It also has no bearing on the Aspen localizer back course, which is correctly labeled, with clear directions on use and application.

The Cali case wasn't an issue of a mislabled procedure, it was a case of a crew failing to obtain clarification, failing to identify, loss of situational awareness, failure to stow speed brakes, failure to verify terrain, failure to identify, and yes, miscommunication (including limited controller vocabulary). You already know this. That has no relationship to the correctly labled back course at Aspen.

One wonders how it was possible the Titanic ever sank?

An iceberg, bad metalurgy, and a failed design that allowed a single stress riser to separate the hull, but that's not important right now. Neither is the loss of the Titanic relevant to a correctly named navaid and course, procedure, and chart, flying into Aspen, Colorado.

Why on earth was the procedure not constructed on a 'front course' of 120? The g/a then back-tracks this localiser a 'course' set of 120, as in many other procedures. I am assuming, of course, that there is no requirement for a 'front course' of 300 in any procedures there, in which case I think this has all been made with unnecessarily complicated?

Because the KASE procedure, as published, eliminates reverse sensing while flying outbound.

I think there is no provision for back-course approaches in the UK, and I have no experience whatsoever in these types of approaches even flying around Europe in the capacity I do, but the give away for me is the "NB" on the chart.

Surely an explicit acknowledgement by Jepperson that the chance of ambiguity exists?

"NB?" Whether one has experience flying a back course or not, it's one basic type of instrument procedure, and if one has an instrument rating or ATP, one should understand it. The instructions on the chart are quite clear. The procedure has been designed to eliminate ambiguity errors by eliminating reverse sensing issues which might lead to disorientation. In the event one is operating with an HSI, which is nearly universally the case today, the matter is largely a non-event.

Is that claim to "normality" contingent on the fact you've called it a "back-course"?

What does "normal sensing" mean in the context of flying a localizer or back course approach? You don't understand this, or you're trying to cloud the issue? We're not talking normal psychology, here. We're not talking normal child development. We're not talking normal schools. We're talking in context about a back course facility (which the I-PKN facility is) with normal sensing.

If you're familiar at all with the concept of a back course procedure (you've stated you've got at least 4,000 hours of flight experience, and apparently you're instrument-rated, so this shouldn't come as any great shock), you'll understand the difference between normal sensing and reverse sensing. If one is instructed that one can anticipate normal sensing when flying outbound on the back course, one knows that given there are only two options (normal sensing vs. reverse sensing), the matter is made clear. One doesn't need to attempt to apply the word "normal" out of context or consider it's higher philosophical implications. Normal sensing when flying a localizer and back course means that when the little needle goes left, you follow it and go left too. (Reverse sensing, of course, means that when the needle goes left, you go right, hence the term "reverse sensing"). This procedure utilizes the back course to provide normal sensing to the pilot, and explicitly states this on the procedure chart, as well as giving only ONE course value (300 degrees) to avoid confusion. Put in 300 degrees, and all is well, one has normal sensing, and one is free to move on to live a life of religious fulfillment.

It's called a "back course" because it is indeed (get ready for it, drum-roll, please) a back course facility, and one is flying outbound on a back course (which, as every instrument student knows, provides normal sensing, as opposed to flying inbound on a back course, which provides reverse sensing).

What does "normal" mean if this is a "non-normal" approach for you?

Again, if you'll leave the procedural note in context, as it's written in plain-english, you'll understand. The procedural note says nothing about a normal approach, or abnormal approach. It specifically states "The I-PKN back course outbound is normal sensing." Again, to belabor the point, normal sensing, vs. reverse sensing. One must consider the context, and read. One can't simply see the word "normal," and apply it to any other use of the word "normal" in the English language (it isn't a normal surgery procedure, normal child, normal pet, or normal pizza, but normal sensing, exactly as it's written).

Even then I still find the note ambiguous. Is it normal sensing when you've dialled up "300" or normal sensing when you've dialled up "120"?

Where do you find "120" in the procedure? You don't. It's 300 degrees, which works whether one has a simple fixed-card CDI, or whether one is using an EHSI display. You don't need to figure out sensing, ambiguity (another one of those terms that you're throwing around out of context, here: ambiguity is a proper term when dealing with the procedure and indications thereof). You have normal sensing available, and clearly are flying outbound on a localizer back course.

The semantics is hugely important.

The semantics are important, which is why the procedure is correctly labled, accurate, and spelled out, and which is why the user is specifically given only one course value to insert, along with a clear notation that normal sensing will be available as one is flying the back course outbound. Go figure.

[Denti]

"NB?" Whether one has experience flying a back course or not, it's one basic type of instrument procedure, and if one has an instrument rating or ATP, one should understand it.

Nope, if you narrow that down to a US ATP you are right, outside of the US a backcourse is very rarely used if at all. In fact, my company tells us quite clearly that using back course procedures is prohibited as we do not train it. I learned how to fly as i did my training in the US, but haven't flown any kind of backcourse procedure since, and of course it was not a topic during my ATPL tests.

[aterpster]

Denti:

Nope, if you narrow that down to a US ATP you are right, outside of the US a backcourse is very rarely used if at all.

Thus, the reason the missed approach LDA at ASE was configured as a back course, so when using it as intended (and it would be difficult to use it not as intended) you get normal sensing.

[SR71]

Guppy,

You can holler all you like about the merits of the procedure and how it is TERPS this and TERPS that, but I, as a pilot prohibited by my airline from shooting back-course procedures like Denti (Why is that?), living in a country where there is no provision for them (Why is that?), and having not done one in at least the last 4000 approaches (not flight hours - go figure the difference) found it, initially, could be interpreted, by myself, as ambiguous.

That being the case, I surmised, perhaps erroneously, that I might not be the only one who felt that way. Of course, the fact that previous contributors alerted me to that fact clouds the issue of causality.

So I went away and looked at some notes. Now I feel better and philosophically disabused.

However, I would suggest that the ambiguity of the plate is contingent on far more than your ability to mount a vociferous defence in its favour.

To this end try and understand my analogy(s) a little less literally.

[SNS3Guppy]

You can holler all you like about the merits of the procedure and how it is TERPS this and TERPS that, but I, as a pilot prohibited by my airline from shooting back-course procedures like Denti (Why is that?), living in a country where there is no provision for them (Why is that?), and having not done one in at least the last 4000 approaches (not flight hours - go figure the difference) found it, initially, could be interpreted, by myself, as ambiguous.

I can't really figure the difference, whereas you've given no indication of your typical leg length or frequency of approaches/landings. Given that you appear to be indicating that your experience is confined to Europe, the legs must be very short, so perhaps there's some rough correlation between the number of approaches and the number of hours. I don't really care, nor is it germane to the conversation; I point this out because you brought it up.

You've been insistent on proper terminology. You don't like the name of the approach, you don't like the naming convention, either. Never the less, whereas ambiguity is an important, precise term with regard to flying VHF navigation, you're happy to confuse ambiguity and ambiguous.

Perhaps you mean nebulous, or perhaps you mean confusing. Who knows?

I don't know why your employer prohibits you from flying back course approaches. Perhaps your employer insists on a lower standard of training. Perhaps there aren't any to be hand, and you visit such a small area that it's not a problem for you. Perhaps you're operating to a very limited number of runways, all served by nice, comfy ILS's. Who knows? You asked, but given the lack of information, the only proper response is "who knows?"

I'm betting you do, and perhaps you'll even share the reason. It may change the speed at which the world rotates, so don't delay.

However, I would suggest that the ambiguity of the plate is contingent on far more than your ability to mount a vociferous defence in its favour.

I would suggest you determine the meaning of ambiguity in the context of VHF navigation. It has nothing to do with my defense (that's defense, with an "s). Vociferous is a big, aggressive sounding word, so like a strange do, we'll leave it aside.

Given that you think you mean that the approach chart is ambiguous (as opposed to the proper term ambiguity, when considering VHF navigation...your choice to harp on the correctness of the terminology here, remember), what exactly do you find ambiguous about the plain-english rendering of "The I-PKN back course outbound is normal sensing?"

We've already determined, early in the thread, that flying toward the nav facility is inbound, and flying away from it is outbound. Therefore, given that you're told it's a back course, you're told it's the outbound course, you're given the oubound course value (300) only (with no other numbers to confuse you), and you're told that it's normal sensing (as opposed to the standard expectation when flying a back course: reverse sensing), then it's really, really hard to see the information on the chart as ambiguous, unclear, improper, inaccurate, or wrong.

To this end try and understand my analogy(s) a little less literally.


A little less literally, you say, but you also told us that semantics are important. Let's be precise, you say. Okay; that's the point of this tangent the thread has taken, anyway. People are upset that the procedure doesn't appear proper, doesn't appear to be accurate, so let's be precise. You tell us semantics are important, yet you tell us not to follow along so literally. You must decide (but don't do it with ambiguity...)

The semantics is hugely important.

Indeed.

[Turbine D]

aterpster

I believe you to be correct at ASE. The airport is in a "box canyon" so to speak. There are two instrument approaches into the single runway:
1. A LOC/DME-E direct in approach.
2. A VOR/DME or GPS-C direct in approach that requires dual VHF navigational receivers.
There is a Roaring Fork Visual RWY15 for day use only with cloud deck and visual minimums.
There are four departures, three use the so called "Back Course":
1. LINDZ SIX requires a climb rate of 465 ft per NM to 10,000 and a left turn to intercept the 300° back course.
2. PITKIN TWO (RNAV) (same route as above)
3. SARDD ONE (OBSTACLE) requires a climb out to 9100 ft, a climbing turn to 270° to intercept the 300° back course. This is used to commence a holding pattern at LINDZ from which one can then proceed east or north when released by ATC.

The fourth departure is a straight out visual departure with cloud deck and visual minimums and can not be used at night.

The so called Back Course is used for missed approaches by turning right and intercepting the 300° back course. It is the only safe way out of the canyon as you are landing into the mountains with mountains on both sides at an elevation of 7820 feet.
At this time of the year you can never count on arriving or departing when you want to due to snow and gusty winds (white-out conditions), it is a very tricky airport.

As for the debate on the "Back Course" terminology, I leave that to the experts.

Turbine D

[PBL]

Terpster and Guppy,

I don't want to sidetrack the thread any more than necessary, but your comments on Cali suggest I need to clarify.

Everybody seems to want to select their favorite causal factors for a given accident, and say "it was *really* this". Analysts such as myself list and discuss all of them. If we want to prioritise some for some reason, we then provide our criteria and perform the selection. The paper which I referenced considers broadly speaking the language issues. It does not consider the others (for that, see our full analysis).

The NTSB letter on the accident to the FAA mentions the very issues that Gibbon and I discussed in the short paper I referenced. There is a reason for that.

Concerning "runway heading",
....the problems US pilots have flying runway heading in the UK when instructed to do so by ATC......

.....I've never found that to be the case. That is, where such isolated cases may exist, these are pilots failing to follow an established ATC direction, not a language ambiguity

Mistaken analysis. It is controllers not following established phraseology. The appropriate response as a pilot is to query the clearance.

And the reason it is no longer established phraseology is ..... ??

Language is an issue.

For example, people here have surmised that hiren.bhingradia is a low-time insufficiently-trained newby, or maybe a simmer, simply on the basis that heshe is not using terminology we consider appropriate. No one has yet considered whether the terminology heshe uses might be what is commonly used in hisher environment. (If so, of course, there is yet another language issue to be sorted!)

PBL

[SR71]

Guppy,

You're hot on the bandwidth, I'll give you that.

You and I both know why Jepperson do not include the note "If you fly around randomly below MSA IMC, you'll bump into something" on their ASPEN plate.

You and I both know why Jepperson include the note "I-PKN backcourse is normal sensing outbound" on their plates.

I do not feel the need to respond to the rest of your commentary for 2 reasons, one far more important than the other:

1) It adds nothing further to the discussion.
2) Judging by your existing conduct on this thread (and many others) you wouldn't afford it any respect anyway, so I won't bother.

Enjoy.

:ok:

[aterpster]

SR71:

You and I both know why Jepperson include the note "I-PKN backcourse is normal sensing outbound" on their plates.

They do on several of the departure charts and on one of the two IAP charts. Why not on both of the IAP charts? Both IAPs use the IPKN LOC for their respective missed approach procedures.

And, why does the LOC IAP require "dual VHF navigation receiver" but the VOR IAP does not.

Weird in both cases.

[aterpster]

PBL:

Terpster and Guppy,

I don't want to sidetrack the thread any more than necessary, but your comments on Cali suggest I need to clarify.

Everybody seems to want to select their favorite causal factors for a given accident, and say "it was *really* this". Analysts such as myself list and discuss all of them. If we want to prioritise some for some reason, we then provide our criteria and perform the selection. The paper which I referenced considers broadly speaking the language issues. It does not consider the others (for that, see our full analysis).

I think I covered the significant causes in Post 28 above. Language issues did not excuse that conduct. The verbal exchanges made it seem like the AAL expected the world to have ATC radar services, and that radar controllers are magicans.

Nonetheless, letting an aircraft depart protected airspace in a wild descent is beyond the pale.

[SR71]

aterpster,

That is weird.

I obviously haven't seen the full set of plates.

Having done a short stint working for Jepperson's main competitor as a Small Chart Compiler and cognizant of who actually does this kind of work, maybe the answer to that question is, oversight?

The charts go through various stages of "checking" before final submission and maybe that plate got missed?

In terms of the physics, isn't the main reason for using a backcourse procedure for the MA here, because, tracking with accuracy is most critical early on in the MA procedure where you are close to the ground and when using a beam radiating from the location of the I-PKN, you gain that accuracy where you need it?

If you used a nav aid based on the position of LINDZ the converse is true, with your ability to track accurately getting better the close you are to LINDZ.

[Zeffy]

The full set of FAA charts can be found here (http://aeronav.faa.gov/index.asp?xml=aeronav/applications/d_tpp) (click the desired effective date and search "ASE").

The fact that FAA and Jepp seem to contain the same discrepancies would tend to indicate that those discrepancies are embodied in government source.

[forget]

Having done a short stint working for Jepperson's main competitor as a Small Chart Compiler and cognizant of who actually does this kind of work, maybe the answer to that question is, oversight?

Interesting that this badly misused word should come up in a discussion on semantics. You mean supervision - not oversight. And don't go blaming Webster. :hmm: It's oversight that causes things to be missed.

[aterpster]

SR71:

The charts go through various stages of "checking" before final submission and maybe that plate got missed?

This problem obviously lies with the source. Having said that, Jeppesen used to be better at challenging such discrepencies than they are today. I need supervision, too, I reversed the IAPs in my previous post.:O

In terms of the physics, isn't the main reason for using a backcourse procedure for the MA here, because, tracking with accuracy is most critical early on in the MA procedure where you are close to the ground and when using a beam radiating from the location of the I-PKN, you gain that accuracy where you need it?

That sums it up. Nothing else would provide the navigation accuracy required to miss some really high terrain during, and just after, that missed approach turn. It is not nearly as critical for the departure procedures.

[SR71]

Interesting that this badly misused word should come up in a discussion on semantics. You mean supervision - not oversight. And don't go blaming Webster. It's oversight that causes things to be missed.

We're a long way from the OP's question but...

Two basic stages (if not more) in chart compilation...

So, perhaps an oversight on the part of the compiler when transcribing the FAA document into the Jepp document (or in this case, from the FAA team actually putting the original document(s) together in the first place?), which, then, at the various stages of quality control/supervision (call it what you want) further up the editorial heirarchy, were also.....what?

So I'm not sure I understand your distinction.

That sums it up. Nothing else would provide the navigation accuracy required to miss some really high terrain during, and just after, that missed approach turn. It is not nearly as critical for the departure procedures.

With this in mind, the VOR procedure at the same field makes a mockery of this type of justification!

Presumably it is rarely flown in comparison to the LOC?

:E

[aterpster]

SR71:

With this in mind, the VOR procedure at the same field makes a mockery of this type of justification!

Presumably it is rarely flown in comparison to the LOC?

I suspect the VOR IAP is flown more because it is authorized for GPS overlay.

I don't follow why you believe the VOR IAP makes a mockery of the missed approach LDA guidance (if that is what you mean).

The valley in which the airport lies has more than adequate room for the intermediate and final segments required for a VOR IAP. The missed approach segment is limiting for both the VOR and LOC IAPs, thus the IPKN LDA guidance is equally critical for both missed approach procedures.

Having said that, in the event of a missed approach folks with RNAV typically fly an RNAV course that overlays the IPKN LDA. Technically, that is not legal, but in practice it works fine.

[SNS3Guppy]

You and I both know why Jepperson do not include the note "If you fly around randomly below MSA IMC, you'll bump into something" on their ASPEN plate.

You and I both know why Jepperson include the note "I-PKN backcourse is normal sensing outbound" on their plates.

I don't presume to know why Jeppesen may include a warning on their chart, but your example is ridiculous. The warning, however tongue-in-cheek you intend to be, is nonsensical, as flying below MSA doesn't guarantee that one will hit something nor does doing so while in instrument meteorological conditions. Accordingly, such a warning would be stupid. Furthermore, as MSA is provided for every chart and is standardized, and the significance thereof fully understood, a nonsensical incorrect note regarding it's application would be superfluous.

NACO publishes the Aspen charts (as does Jeppesen) with a notation on the localizer course because it serves to clarify the procedure and show very plainly what is to be done and what is to be expected. Proper terminology is used, specifying normal sensing vs. reverse sensing. Procedural notes are used on approach, arrival, and departure charts where necessary to clarify the procedure, and that's exactly what is done with the statement "I-PKN backcourse is normal sensing outbound."

Perhaps you know something more about this that you're not telling us? You stated that you and I have a collective knowledge about that statement, and I very much doubt that's true, so if you have additional insight to offer, spit it out. I'm all ears.

With this in mind, the VOR procedure at the same field makes a mockery of this type of justification!

Presumably it is rarely flown in comparison to the LOC?

I've flown the VOR procedure many times at KASE. How, exactly, does it make a mockery of Aterpster's comments?

The localizer approach to the runway at ASE takes place through a different canyon than the departure while following the back course. Furthermore, the canyon and terrain widens and opens up as one departs away from Aspen on the back course, toward Lindz. Aterpster's comments are accurate and correct.

Most operators who fly into Aspen won't fly the approaches if the weather is below Red Table VOR, and won't go in there at night. Night restrictions and circling restrictions took place a few years ago following a well-publicized crash. I've circled there many times in the past, as well as arrived and departed at night, before these changes took place. My personal preference is arriving in the day when I can see the runway from the start of the procedure, and this is how most operators go there, too.

Insofar as your assessment of Aterpster's comments regarding the necessity for the accurate back-course guidance on the missed approach, there's no inconsistency. The VOR and Localizer approaches have different ground tracks, different obstacles on the approach, and different initial altitudes. Whereas the VOR approach begins at the highest terrain, it provides the most accurate guidance closest to that terrain. The localizer approach provides accurate guidance throughout, but most accurate closer to the runway. Both execute their missed approaches at about the same place, using the same procedure, and both utilize the back course for accurate course guidance terrain avoidance during the missed.

In turn, the localizer back course is most accurate near the transmitter, which is where it's closest to the terrain and the most critical. As one climbs out toward LINDZ, one gains terrain clearance vertically and laterally, and the canyons open up. The localizer back course is well placed to provide the most accurate course guidance where it's most needed, and there is no "mockery" of anything. It's actually a well-reasoned approach, particularly given the terrain. If you've never flown there, you might not fully understand why. What you would understand, however, is what's required of you as a pilot, because it's clearly shown on the approach charts and departure procedures.

[galaxy flyer]

Aterpster

Perhaps, Jeppesen was better at challenging the FAA TERPS office when their V-P in charge was named Terpstra. Jim is wonder of knowledge on the subject and, in my two meetings, a gentleman.

GF

[SNS3Guppy]

Oh, sure. Let the cat out of the bag, why dontcha!

[aterpster]

galaxy flyer:

Perhaps, Jeppesen was better at challenging the FAA TERPS office when their V-P in charge was named Terpstra. Jim is wonder of knowledge on the subject and, in my two meetings, a gentleman.

Knew Jim well and worked with him a lot. His successor is a sharp guy, too.

This has more to do with staffing levels and insights of past workerbees vs. present.

It is somewhat like the FAA staffs who design these procedures. They used to be pilots and used to be more accountable to the various FAA regions.

[SR71]

aterpster,

My comment was merely drawing an analogy between the fact that, if one accepts that you want your precision guidance close to the nastiest terrain, then one presumably also accepts one wants it closest to the runway. But tracking away from the DBL towards the runway obviously isn't giving you that.

Then I thought about it, and, I guess there isn't much point sticking a VOR at the bottom of a valley, and bearing in mind you locals who know the terrain say there is room for manoeuvre in the vicinity of the MAP, the benefits of locating the beacon out there outweigh the contravention of the general principle in the aforementioned paragraph.

In addition Guppy makes the good point about the benefit on the VOR approach:

Whereas the VOR approach begins at the highest terrain, it provides the most accurate guidance closest to that terrain

However, Guppy also says:

I don't presume to know why Jeppesen may include a warning on their chart...

then says

NACO publishes the Aspen charts (as does Jeppesen) with a notation on the localizer course because it serves to clarify...

so really, unless he is playing on the distinction between NACO and Jepp, he knows what the note is there for like I said.

But, purely in the interests of curiousity:

1) Why is that note not on the FAA VOR plate? Is it on the Jepp VOR plate?
2) Why does the FAA plate suggest dual nav receivers are needed for the VOR and not the LOC? What do the Jepp plate(s) say?

:confused:

[aterpster]

SR71:

But, purely in the interests of curiousity:

1) Why is that note not on the FAA VOR plate? Is it on the Jepp VOR plate?
2) Why does the FAA plate suggest dual nav receivers are needed for the VOR and not the LOC? What do the Jepp plate(s) say?

Jepp and FAA charts are identical as to the notes, or lack thereof. The FAA has been informed of the discrepencies today. Stay tuned.

[galaxy flyer]

You think this confusing, the GLEX nav database approaches for KASE do NOT match any of the plates. VMC at Red Table or join the crowd at Rifle or Eagle.

GF

[Zeffy]

GF

You think this confusing, the GLEX nav database approaches for KASE do NOT match any of the plates. VMC at Red Table or join the crowd at Rifle or Eagle.

That's because the NZ-2000 FMS doesn't do any circling-only approaches. So it's not just at Aspen.

The Aspen approaches in your database are Special Approaches.

Check this recent "Direct-to" Newsletter (http://www51.honeywell.com/aero/common/documents/FMS_DirectTo_3rd_Editionrev1.pdf.pdf).
Question: Some approach procedures do not match the paper charts. Why?

Answer: Our The NZ-2000 database contains some special instrument procedures which require written authorization from your Principal Operations Inspector or Flight Standards District Office prior to use. Special charts are required in all cases and additional aircrew training and specific aircraft performance may be required. A current list of special approached can be obtained from honeywellaes.com. As well as the special procedures that are included in the navigation database, FMS software versions NZ6.0 and Primus Epic 7.0 and prior do not support circling approaches. If your FMS software version does not support circling approaches, they will not be available for selection into the flight plan.
The Aspen Specials are a boon to operators willing to obtain the requisite approvals from FAA Flight Standards.

There's a straight-in version of the LOC/DME-E (Approach title is LOC/DME Rwy 15) and an RNAV (GPS) Rwy 15.

[galaxy flyer]

Thanks, Zeffy, one learns something everyday, if one pays attention.

GF

[tommy1-8706]

Flt Sim 2004 instals IPKN as a Localiser with course 120 degrees.
Hence, heading 300 in a Cessna, say, the needle is not normal sensing.

[PBL]

terpster and SR71 have raised the issue of nav data base integrity (paper or electronic, issues are similar). It's a lot more complicated than just a couple of places where things can go wrong.

I don't recall either terpster or SR71 being on the bluecoat list. The Bluecoat 2001 annual meeting was held at LHR just a month after 9/11. It wasn't super-well attended because of that, but there were some very informative talks indeed. One was from Lee Carlsen, of Smiths, in Grand Rapids, Michigan, who talked about the issues of nav data base integrity. I wrote up a conference report. Here are my notes on Lee's talk. I apologise for the length.

I am also concerned about thread creep. Over the time I've been on PPRuNe I think I have tried to start three threads. Each one has silently disappeared within minutes of my starting it. However, my contributions to existing threads don't disappear. JohnT moderates transparently and I'm sure he will make the necessary structural changes if this is too much creep.

[begin Bluecoat 2001 notes on Lee Carlsen's talk]

Lee Carlsen told us about Nav database integrity, lavishly illustrated with some unnerving photos from Unusual Aviation Pictures (http://www.aviationpics.de) . He succeeded in persuading me, at least, of the significance of this problem of heterogeneous engineering. The chain is as follows.
1. Survey;
2. Compilation of survey data by the state or official agencies;
3. Data given to DB providers (Jeppesen, Thales, etc) for processing;
4. Data processed by DB providers;
5. Formatted data given to Navionics providers for formatting and compactification for their products;
6. Product-adapted data returned to DB provider for distribution to customers;
7. Distribution to customers;
8. Installation in airplane;
(9. Pilot's fingers......).
During any of these processes, data could become corrupted. Surveyors make mistakes (or, in some cases, require and provide half their data as WGS-84 and another half using traditional measures, as in Mexico), and at any other point in processes 2 through 6 finger trouble at data entry or lack of correctness of programs processing the data can cause corruption. Customers may not necessarily install new data correctly. And all that before it gets to the pilot. Lee gave us a quick survey of the methods that can be reasonably applied to assure high integrity: tools can be provided to the DB producers to check output against input for steps 4 and 5, and to check output to step 6 against output to step 4 (and thus against input to step 4 for those with a tool for this also). Output can be assured wrt input for steps 3 and 7 by including error detection (or even error-correcting encoding) on the distribution medium. Such methods could also be used to prevent successful installation if there is any data corruption on the medium.

However, while all this is technically trivial, it is a significantly large if not gargantuan task of heterogeneous engineering involving many actors, some of whom (such as the states) are not necessarily motivated by any externalities such as a threat of getting sued over mistakes.

In my own work I encounter data integrity problems, and their significance for safety-related systems cannot be underestimated. But the problem of assuring integrity seems to be much more difficult than I had heretofore thought it.

[end Bluecoat 2001 notes]

PBL

[stubby1]

The funda is that your instrument senses the two lobes and assumes that you are flying the set course in ILS.
so in this case you put the course to the final & arm the back course.
the confusion is over the term "back course' which actually means something else (behind the localiser). however the use of this reverses the lobes & you get correct guidance on the outbound. Backcourse can be simply read as reversing the sense. you can also use it in flying the actual back course ( not in India).
.

read this slowly to digest. you can also check with do-228 pilots for clarification.

here you are flying outbound of front course.

[aterpster]

tommy1-8706:

Flt Sim 2004 instals IPKN as a Localiser with course 120 degrees. Hence, heading 300 in a Cessna, say, the needle is not normal sensing.

That program has many errors. It was written by programmers, not experienced pilots.

It's a game, not a simulator.:)

[aterpster]

PBL:

In my own work I encounter data integrity problems, and their significance for safety-related systems cannot be underestimated. But the problem of assuring integrity seems to be much more difficult than I had heretofore thought it.

I can only speak to the process in the U.S.

1. Survey issues and significant missed obstacles are resolved in initial flight inspection.

2. Source data for government chart-makers and third-party chart-makers is often, but not always, identical.

3. Errors in procedural data notes, such as uncovered in this thread at ASE, are a very weak link in the process, but this affects charts, not databases. And, incorrect or confusing procedural notes tend to create a "primrose path."

4. The FAA itself shows its own doubts about database integrity by requiring a second round of very controlled nav database verification for RNP AR IAPs (the "golden database.") (RNP AR is being terribly overused in the U.S., and well beyond its intended purpose, but that would make for its own thread.)

[galaxy flyer]

Aterpster

I'd like to hear your thoughts on the overuse of RNP AR IAPs, either here, in a separate thread or off-line. I can PM an email address, if you rather

GF

[aterpster]

gf:

I'd like to hear your thoughts on the overuse of RNP AR IAPs, either here, in a separate thread or off-line. I can PM an email address, if you rather.

Example: KGPI Runway 20, great application; Runwy 2, unnecessary.

Example: KRDU, all runways unecessary except for presumed fewer (green) flight path miles. This is like killing flies with a shot gun. But, the FAA and ICAO failed to develop comparable flight path criteria for fuel savings and non-critical obstacle clearance.

[aterpster]

It took some time but the FAA issued these NOTAM amendments today:

!FDC 1/3701 ASE FI/P ASPEN-PITKIN CO/SARDY FIELD, ASPEN, CO. VOR/DME OR GPS C, AMDT 4F... CHART PLANVIEW NOTE: I-PKN BACK COURSE OUTBOUND IS NORMAL SENSING. THIS IS VOR/DME OR GPS C, AMDT 4G.

!FDC 1/3699 ASE FI/P ASPEN-PITKIN CO/SARDY FIELD, ASPEN, CO. LOC/DME E, AMDT 1... CHART PLANVIEW NOTE: DUAL VHF NAVIGATION RECEIVERS REQUIRED. THIS IS LOC/DME E, AMDT 1A.

[SNS3Guppy]

Good job. Another great mystery solved (and fixed).