ILS DME
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Substitution of a suitable RNAV system for DME is authorized for aircraft of U.S. registry under Advisory Circular 90-108, which is available on the FAA's website for download.
So if the approach plate clearly states "DME REQUIRED" AND there are defined DME fixes on the final approach segment, I would believe that RNAV could NOT be legally used in place of DME.
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Question nr1:NO
Question nr2:YES
DME on top of chart is not mandatory if replaced by other means(timing,radial..)
DME next to minima is Mandatory.
Now if you use Lido,you must have charts explanation,please have a look.
Question nr2:YES
DME on top of chart is not mandatory if replaced by other means(timing,radial..)
DME next to minima is Mandatory.
Now if you use Lido,you must have charts explanation,please have a look.
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Interesting. That would mean that no 737 could legally fly an ILS into EDDP as that has DME next to its minima box in LIDO and that DME is based on a different frequency than the ILS. Still we do fly it, just replace the DME with FMC computed waypoints.
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Intruder:
You are missing a critical word in Paragraph 8.b, and I quote:
"8 b. Substitution on a Final Approach Segment. Substitution for the NAVAID (for example, a VOR or NDB) providing lateral guidance for the final approach segment."
That prohibits substitution of the localizer, not the DME.
However, such substitution is NOT allowed on the final approach segment, per par. 8.b of that AC...
"8 b. Substitution on a Final Approach Segment. Substitution for the NAVAID (for example, a VOR or NDB) providing lateral guidance for the final approach segment."
That prohibits substitution of the localizer, not the DME.
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Here is the entire advisory circular for those who are interested. Paragraph 8 c. is more on point:
AC 90-108 - Use of suitable Area navigation (RNAV) system on Conventional Routes and Procedures ? Document Information
AC 90-108 - Use of suitable Area navigation (RNAV) system on Conventional Routes and Procedures ? Document Information
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"8 b. Substitution on a Final Approach Segment. Substitution for the NAVAID (for example, a VOR or NDB) providing lateral guidance for the final approach segment."
That prohibits substitution of the localizer, not the DME.
That prohibits substitution of the localizer, not the DME.
To me, in context, "lateral" means in the XY plane, as opposed to vertical (Z axis). RNAV includes lateral and vertical guidance/navigation (LNAV and VNAV), and LNAV or lateral guidance/navigation includes azimuth and distance.
I have trouble resolving that, in context, "lateral" means side-to-side or Y axis (or LOC, as you noted) movement, as opposed to longitudinal (or DME to a straight-ahead NAVAID) guidance. After all, DME/DME or GPS or WAAS updating requirements of par. 11 provide provide primarily "lateral" (XY plane), as opposed to vertical, updating.
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Intruder:
I recommend you contact the department that wrote AC 90-108. I am not going to debate with you an official FAA document, which everyone involved in IFR operations in the U.S. accepts, understands, and has used and related preceding documents ever since the FAA first authorized the substitution of suitable RNAV navigation equipment for DME.
I accept that is what it means to you. 
Again, I recommend you contact the FAA department that wrote AC 90-108.
Please provide a reference for context definition of the term "lateral guidance" in par. 8.b, as well as "lateral navigation" in 8.c.
To me, in context, "lateral" means in the XY plane, as opposed to vertical (Z axis). RNAV includes lateral and vertical guidance/navigation (LNAV and VNAV), and LNAV or lateral guidance/navigation includes azimuth and distance.
I have trouble resolving that, in context, "lateral" means side-to-side or Y axis (or LOC, as you noted) movement, as opposed to longitudinal (or DME to a straight-ahead NAVAID) guidance. After all, DME/DME or GPS or WAAS updating requirements of par. 11 provide provide primarily "lateral" (XY plane), as opposed to vertical, updating.
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De facto,
Thanks for reply!!
I did look at the legend and found it to be confusing! I did bring it up with the flight department and they are looking into it .
To me if the header says, for example, ILS+DME than the DME is required, if it merely says ILSDME than it becomes more confusing! Annex 6 says that only the navigation device providing lateral guidance should be mentioned in the header. Other navigation devices required should be mentioned in the plan view under a note. It seems lido makes a mistake in this sense according to me. Further more, reviewing many charts LIDO also seems to be inconsistent in that sometimes it designates some ILS's with a DME in the minima box when it doesn't say ILSDME in the header and sometimes it has merely ILS in the header with an ILS that has DME and it states DME in the minima box!!
I forwarded the question to the flight department and they are looking into it, however, I wanted to get some input from fellow proffesionals!!
My company comes out with a scenario each month to think about. The scenario was, you are flying to Ams and the only ALT is EHEH, the WX is right at LOC minima(or any NPA) but the DME is inop. EHEH is a cat 1 field so in order to plan it you need NPA mins. So do you in the planning phase need the DME to be operative? Or can you use FMS to substitute for the inop DME? Further more, in actually diverting and flying the ILS can you do this or do you need the DME to be operative?? In my opinion, when flying any ILS you need an OM or equivalent position, the question is? How do you determine equivalent position? To me FMS is adequate to determine equivalent position!!
Like I said, I wanted to get some input
Thanks for reply!!
I did look at the legend and found it to be confusing! I did bring it up with the flight department and they are looking into it .
To me if the header says, for example, ILS+DME than the DME is required, if it merely says ILSDME than it becomes more confusing! Annex 6 says that only the navigation device providing lateral guidance should be mentioned in the header. Other navigation devices required should be mentioned in the plan view under a note. It seems lido makes a mistake in this sense according to me. Further more, reviewing many charts LIDO also seems to be inconsistent in that sometimes it designates some ILS's with a DME in the minima box when it doesn't say ILSDME in the header and sometimes it has merely ILS in the header with an ILS that has DME and it states DME in the minima box!!
I forwarded the question to the flight department and they are looking into it, however, I wanted to get some input from fellow proffesionals!!
My company comes out with a scenario each month to think about. The scenario was, you are flying to Ams and the only ALT is EHEH, the WX is right at LOC minima(or any NPA) but the DME is inop. EHEH is a cat 1 field so in order to plan it you need NPA mins. So do you in the planning phase need the DME to be operative? Or can you use FMS to substitute for the inop DME? Further more, in actually diverting and flying the ILS can you do this or do you need the DME to be operative?? In my opinion, when flying any ILS you need an OM or equivalent position, the question is? How do you determine equivalent position? To me FMS is adequate to determine equivalent position!!
Like I said, I wanted to get some input
Last edited by flyburg; 20th Oct 2014 at 09:53.
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My company comes out with a scenario each month to think about.
We moved away from "DME" in the title a few years ago, I think because of database issues: it was a "number of characters in the FMS database naming convention" limitation.
We now have only "VOR", "NDB" or "ILS" named procedures, but the DME requirement is stated on the chart:
We now have only "VOR", "NDB" or "ILS" named procedures, but the DME requirement is stated on the chart:
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The point is, flyburg, by posing the question here you will get any number of answers - from wannabees, armchair quarterbacks, flt simmers, experts, self-professed experts etc etc all of which may or may not be correct for your operation.The ONLY correct answer is what YOUR company tell you.
There are two answers, of course, one as above and then the 'practical' one, which in the case of EHEH would be just get on with it (possibly 'illegally') , monitoring ANP. However, in the odd case elsewhere where lateral manoeuvring may be 'forbidden' until the published MAP you WILL need to know where that is - even on your ILS.
There are two answers, of course, one as above and then the 'practical' one, which in the case of EHEH would be just get on with it (possibly 'illegally') , monitoring ANP. However, in the odd case elsewhere where lateral manoeuvring may be 'forbidden' until the published MAP you WILL need to know where that is - even on your ILS.
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It is a good thing you ask your airline directly...after reading LiDO charts...i agree there seems to be some unclear wording indeed.
Not only rnav equipped aircraft use lido charts i reckon,in there lies the problem.
Not only rnav equipped aircraft use lido charts i reckon,in there lies the problem.
Correct. If you can't use GNSS (because it is not stated as such on the chart), as a replacement for the DME if the DME (or the on-board DME receiver) is U/S, then you can't do the approach.
In this case, there is an alternative ILS, using the DME on the glidepath. GNSS cannot be used in that case.
In this case, there is an alternative ILS, using the DME on the glidepath. GNSS cannot be used in that case.
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De facto,
Your answer was correct! The procedure name is merely taken from the IAP an has no meaning unless it has a + symbol.
If it has a navaid in the minima box then that navaid is required. However, company came back and said that LIDO is not very consistent in their charting.
Why for example does it sometimes include the identifier of the navaid in the minima box and sometimes it doesn't?
For example EDDP, it states DME for the ILS approaches but then specifically the ident for the LOC only approach!!
Furthermore EHEH again, according to LIDO you can't fly this approach if the DME is inop but if you would use Jeppesen I can't see a reference that you wouldn't be able to fly the approach if the DME is inop.
Your answer was correct! The procedure name is merely taken from the IAP an has no meaning unless it has a + symbol.
If it has a navaid in the minima box then that navaid is required. However, company came back and said that LIDO is not very consistent in their charting.
Why for example does it sometimes include the identifier of the navaid in the minima box and sometimes it doesn't?
For example EDDP, it states DME for the ILS approaches but then specifically the ident for the LOC only approach!!
Furthermore EHEH again, according to LIDO you can't fly this approach if the DME is inop but if you would use Jeppesen I can't see a reference that you wouldn't be able to fly the approach if the DME is inop.
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You know what would have been really useful would have been a post of the LIDO chart for EHEH since many never see this type of chart. I assume LIDO are at the 'cheap' end of chart production. You gets wot u pays for.
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I can only post a snapshot picture of the approach but don't know how to do that unfortunately.
LIDO is Lufthansa integrated dispatch operations or something, I didn't realize they are the cheap end of chart productions
LIDO is Lufthansa integrated dispatch operations or something, I didn't realize they are the cheap end of chart productions