ILS DME

[flyburg]

Frankly admit, I'm at a loss

When using LIDO charts, the header says ILSDME

The minima box specifies cat1dme

are you legally permitted to fly the ILS when the DME is inop? There are coded FMS waypoints to establish the equivalent position!

Are you in the planning fase allowed to plan this airport as an alternate? In the profile box it has timing to determine the mapt.

What I'm asking, if it says in the header ILSDME is the DME required or are you allowed to apply the inop component table and substitute the inop DME by FMS position

[BOAC]

inop component table - what is that and what does it say?

[MCDU2]

Post a chart or tell us which airfield and runway. Also is there another dme to use such as off a VOR?

[flyburg]

Eindhoven EHEH

[BOAC]

How do you propose to determine MAP?

[flyburg]

Is that a trick question?

ILS when reaching the DH, loc by timing from the coded FMS waypoint overlaying point D.

That was the question, you can fly it without DME but are you allowed when it says DME in the approach title?

[Piltdown Man]

Hi Flyberg,

I think the the answer you are looking for is in the Lido Legend booklet, page LAT 410 where it states: "If two or more independent NAVAIDs or components thereof are required, they are separated by a ”+” (plus) and the principal NAVAID used for final approach and for the determination of landing minima". As both of Eindhoven's approaches are written as ILS DME Y, your plan of substituting an FMS fix to independently confirm your position is a good one. But it has to be between three and five miles so you can confirm you haven't picked up a false glideslope. Therefore I believe you can use EHEH as an alternate with standard ILS minima when the DME in U/S. But rather interestingly, the NDB DME approaches require the EHV DME to determine crossing altitudes yet the neither of these approaches are written as NDB+DME. I shall ask my colleague tomorrow. Ex Koko's are clever chaps and know most things.

[OhNoCB]

I don't know LIDO charts but on the Navtech I have beside me for Gatwick, the non LVO options are ILS+DME, LOC+DME and Circling. There is also a note to say that aircraft unable to receive the DME will be given RADAR ranges at FAP and 4nm.

Perhaps this is a legal requirement if there is no DME (I don't know).

[flyburg]

Hi PM,

That was my initial thought as well, however, how do you read LAT690 approach minimum sub designator? This suggest that DME is required!

Thanks

[aterpster]

The OP didn't state which ILS at EHEH. Here are both of them:

http://i201.photobucket.com/albums/aa214/aterpster/11-1_zps72b9a728.jpg

http://i201.photobucket.com/albums/aa214/aterpster/11-2_zps6d0c98bb.jpg

Here is an ILS in the U.S. that requires DME if the G/S is unavailable. Note that the DME fixes are named, which is FAA policy. Those named fixes can be substituted for DME in an RNAV equipped aircraft:

http://i201.photobucket.com/albums/aa214/aterpster/KACVILS32_zps20a37c35.jpg

[BOAC]

Those named fixes can be substituted for DME in an RNAV equipped aircraft:- why does the Jepp not reflect this? It clearly states 'DME Required' which to me is a clear statement. Is that in bold print or is it just the scanned copy?

[Mach Jump]

It's always been my understanding that if both ILS and DME are in the title, then they are both required for the approach, unless there is provision for radar callouts of the significant ranges. I'm not familiar with LIDO charts, but, if the significant points are only identified by DME ranges, then how are you going to cross check the glideslope without DME? I know that some of my colleagues think that GPS range from the threshold is acceptable as 'DME' but I'm not of that opinion.

[MarkerInbound]

BOAC -Jepp does print the restriction in bold. To the OP, I'd say don't go missed.:cool:

[aterpster]

BOAC:

- why does the Jepp not reflect this? It clearly states 'DME Required' which to me is a clear statement. Is that in bold print or is it just the scanned copy?

It is in bold print. For all I know a suitable RNAV system may not be an authorized substitution for DME for foreign operators. The Jepp chart is not limited to use by FAA registered aircraft.

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.

[glendalegoon]

arcata/eureka, a very, very foggy place. once used for earliest experiments in blind landings. been there with two different airlines. unique airport!

[BOAC]

The implementation of RNAV approaches appears to be a worldwide muddle with different 'rules'/'excepetions'/'authorisations' etc depending on national and even sometimes company rules. A minefield. Such a shame, since the principle is sound. It would appear the OP simply needs to ask his/her company for the answer rather than PPrune.

[de facto]

If your minima show CAT1 DME ,then DME is required.
If your approach minima can be used with time for example (as a back up) then DME will not be shown next to the approach type.

[BOAC]

If your minima show CAT1 DME ,then DME is required. - not much help with a Jepp!

[de facto]

His question was ,using LIDO,if minima show CAT1 DME 200ft/550rvr then to legally fly that ILS, DME must be operative.

[flyburg]

De facto,

Actually two questions

1 If DME stated in tittle is DME required?

2 if DME stated in minima box is DME required

This only for lido charts as jeppessen charts seem to use another logic!

Inclined to believe your answer, but a lot of inconsistencies

Look for example at EHEH as I gave, then at nairobi! ILSDME not stated in the title, however, it is stated in the minima box! Several coded FMS waypoints and even a note that missed approach timing is NA. Can I or can I not fly an ILS with the DME inop(obviously not a loc approach since the note says timing not to be used and the only way to identify Missed approach point is DME)?

[Intruder]

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.
However, such substitution is NOT allowed on the final approach segment, per par. 8.b of that AC...

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.

[de facto]

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.

[Denti]

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.

[aterpster]

Intruder:


However, such substitution is NOT allowed on the final approach segment, per par. 8.b of that AC...

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.

[aterpster]

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 (http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentid/946030)

[Intruder]

"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.
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.

[Capn Bloggs]

RNAV includes lateral and vertical guidance/navigation (LNAV and VNAV)
Not here. RNAV is "Area Navigation".

[aterpster]

Intruder:

Please provide a reference for context definition of the term "lateral guidance" in par. 8.b, as well as "lateral navigation" in 8.c.

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.

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 accept that is what it means to you. :)

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.

Again, I recommend you contact the FAA department that wrote AC 90-108.

[flyburg]

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

[BOAC]

My company comes out with a scenario each month to think about. The whole implementation of RNAV procedures across the board seems to me 'a dog's breakfast' and would appear to be significantly company manual dependent. So, since they have asked the question, one hopes ?someone knows? and therein lies your (only correct) answer...............

[flyburg]

Thank you BOAC!

[Capn Bloggs]

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:

http://s26.postimg.org/r3rbd7qa1/DME_Reqd.jpg (http://postimage.org/)

[BOAC]

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.

[de facto]

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.

[Capn Bloggs]

Furthermore, a lot of our charts allow GNSS to replace the DME:

http://s22.postimg.org/udb2pt94h/GNSS_in_lieu.jpg (http://postimage.org/)

[Intruder]

In that case, does lack of specific permission for the replacement mean it is NOT allowed?

[Capn Bloggs]

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.

[flyburg]

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.:confused:

[BOAC]

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.

[flyburg]

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

[BOAC]

The clue might be here company came back and said that LIDO is not very consistent in their charting. - If they are not 'cheap' then you are being ripped off:) If you wish to PM me a link to dropbox or whatever I will post for you.

[flyburg]

How do you post a picture from your IPad on this forum?

[aterpster]

How do you post a picture from your IPad on this forum?

Post it on Photobucket or similar service, then link it here using the "Insert Image" option.

[BOAC]

Lido chart posted for flyburg

http://img.photobucket.com/albums/v293/boacphotos/foto_zps3d153052.jpg

[Denti]

Quite honestly i wouldnt read out of that chart that my DME receiver has to be operable as the relevant DME distances are backed up by RNAV waypoints which would be coded in the database for that approach.

However, as the DME is based on the LOC frequency there shouldn't be that big a problem to begin with as tuning of the ILS gives both the ILS and the DME information unlike EDDP where you would have to tune the ILS and another navaid to receive both the ILS and the DME, which is difficult to do with just two pilot tuneable nav receivers as both are needed for the ILS.

[BOAC]

as tuning of the ILS gives both the ILS and the DME information - except as per post #1?

flyburg - having seen the chart, I repeat - it is a company problem. They MUST make clear to crews how to interpret the charts with which you are provided. I E IF 'CAT1 DME' is to be interpreted as DME required or 'where RNAV waypoints are charted and coded in the FMC database, RNAV may be substituted' etc etc. I cannot interpret that chart. We can guess, pontificate and surmise all day and night and not be 'right'. Yes, it is perfectly practical and safe at EHEH on that procedure given the required ANP, but as I posted before, the ONLY correct answer is in your Ops Manual. I assume you have diligently ploughed through all LIDO chart guidance material and there is no clue?

[flyburg]

Yes I have, unfortunately, the wording in the legend are ambiguous.

I left it at the company. I started the discussion here in hope of getting some input from other LIDO users but I'll just wait for the official answer.

Thanks all for the input!!

(and thanks for taking the time posting the chart BOAC).

[chkflgtpilot]

This is a very interesting discussion! I also have to rely on LIDO nowadays, and I agree that it is not always crystal clear how the information should be interpreted. However, one should assume that the published material is based on official documentation such as essentially AIP. Unfortunately, I have previous experience from other manual systems that compliances with the AIP are not always 100%.

If you enter "AIP Netherland" on Google, you will after some clicking find the "Electronic AIS publications" and from there you should be able to find the document "AD 2.EHEH-IAC 21.1" (PDF) describing the "ILS / DME Y" including "GP INOP".

Even in this (more or less) official document the EH-waypoints are described (including coordinates). In fact, also the coding of the FMS NDB is described in the text pages (which you as a pilot rarely has a reason to care about). However, what is interesting is Note 2 on the IAC, namely - "Given EH-waypoints beyond the FAF must be considered to be supplementary information to the published non-precision final approach (see also page EHEH AD 2.22)."

To me, this sounds like the EH-waypoints officially are for guidance (or awareness) only after the FAF, which harmonizes with an official requirement for DME. Furthermore, note that there is no officially published WP for the MAPt in the document AD 2.EHEH-IAC 21.1, but the reference is "THR 0.2 EHO." I.e. you need DME to "officially" determine the MAPt, while LIDO has the WP "RW21" on their chart (not 100% consistent with the AIP). :hmm:

Do you need to be able to determine the MAPt located at the threshold if you fly an ILS approach? The DA is in any case well before the threshold, and a missed approach should be initiated at DA at the latest. In reality, this is unlikely to be a problem, but formally a missed approach shall be flown via the MAPt, located where?

As usual, it is not always easy to get the official theory work together with the everyday practice. ;)

I am looking forward to hear what reply you get from your company!