mark767 Posted August 30, 2015 Share Posted August 30, 2015 Yesterday I flew the AAL flight from KDFW to KEGE with the planned arrival being the LDA 25. I was flying the PMDG 737 (yes, even though AA used the A319 on this particular flight). The FMC was programmed correctly for the waypoints on the LDA but when I selected LOC the aircraft veered quite far off course. Note that I did have the course of 246 programmed in correctly. I ended up abandoning the LOC and going back to LNAV to complete the arrival. So my question is this....is there an error in the way the ILS is programmed in this scenery ? Link to comment Share on other sites More sharing options...
AKar Posted August 30, 2015 Share Posted August 30, 2015 The loc array is quite a bit offset there - I wouldn't expect anything else! Link to comment Share on other sites More sharing options...
Voyager Posted August 30, 2015 Share Posted August 30, 2015 Hi Mark In fact this is an approach not aligned with the runway and once the DME information is essential. Just this information is missing and the FMS doesn't know where it's. See the screenshot below. KEGE LOC / DME I-ESJ 109.75 (localizer) Cheers, Voyager Link to comment Share on other sites More sharing options...
wulfbindewald Posted August 30, 2015 Share Posted August 30, 2015 Here a pic, which shows the wrongly aligned localizer named I-EGE. I guess this is an old definition when FSX came up.... Acc. to the KEGE manual the LDA/DME RWY25 (I-ESJ, 109.75) should contain a glide path with an offset of 3.9°, starting from the rwy fwd. end and includes only a glide path and DME, but not a glide slope. IMO this should be better highlighted in the support forum. Wulf Link to comment Share on other sites More sharing options...
AKar Posted August 30, 2015 Share Posted August 30, 2015 Acc. to the KEGE manual the LDA/DME RWY25 (I-ESJ, 109.75) should contain a glide path with an offset of 3.9°, starting from the rwy fwd. end and includes only a glide path and DME, but not a glide slope. I'm not sure what you're saying? Glide or not glide? Anyways, there is a glideslope antenna at somewhat "short" from the regular touchdown area, and a localizer antenna definitely offset from the runway centerline out there behind the airport. The localizer course should go approximately over the runway threshold as measured in Google Earth, and I checked my measurement against the official localizer heading and that matches. I posted a pic of the localizer position above but unfortunately Dropbox is down so it is not visible. Edit: now working! Anyways, your red boxes seem to point a bit missed from the actual localizer array location, though it is hard to say accurately. The glideslope position may be also just a bit too far, but again, hard to say. Link to comment Share on other sites More sharing options...
Voyager Posted August 30, 2015 Share Posted August 30, 2015 Hi Mark Well, in short: Mark you'll not be able to do the LDA 25 because the FMC will not solve the problem of discontinuity: it has a direction (course) but has no distance indication (KEGE rendition lost DME). That's why the FMC disarms the final approach on localizer. IMHO, you can launch the ticket for this lack of DME at I-ESJ 109.75 frequency in the appropriate forum: http://www.orbxsystems.com/forum/forum/15-full-terrain-experience-ftx-payware-support-forum/ Cheers, Voyager Link to comment Share on other sites More sharing options...
mark767 Posted August 30, 2015 Author Share Posted August 30, 2015 I understand that it is ofset but the path goes through waypoints AQUILA WEHAI AIGLE WASHI CIPKU. This should happen if you fly LNAV through these waypoints or fly the ILS 25 on a course of 246 at frequency 109.75 but it does not seem to do so. I will give it another try this afternoon to see if I am missing something here. Link to comment Share on other sites More sharing options...
AKar Posted August 30, 2015 Share Posted August 30, 2015 Yes indeed it should. And that is easily confirmed to be consistent with actual location by independent data by comparing some sources. It likely is off then in the scenery - maybe this is an issue with mag vs true heading? The locs should be aimed to true heading only when reproducing the world. -Esa Link to comment Share on other sites More sharing options...
mark767 Posted August 30, 2015 Author Share Posted August 30, 2015 Yes indeed it should. And that is easily confirmed to be consistent with actual location by independent data by comparing some sources. It likely is off then in the scenery - maybe this is an issue with mag vs true heading? The locs should be aimed to true heading only when reproducing the world. -Esa Interesting. I just tried it again in the PMDG NGX. The setting for Mag vs True was default so maybe that is the issue. Anyway, I tried it again and there is a direrging path between the chart path and the path flown on the LOC. Turns out it still puts you on an offset ILS and pretty easy to land but in IMC conditions I don't think anyone would be very comfortable moving off the charted path with the terrain surrounding this airport. Link to comment Share on other sites More sharing options...
Rob Newman Posted August 30, 2015 Share Posted August 30, 2015 Acc. to the KEGE manual the LDA/DME RWY25 (I-ESJ, 109.75) should contain a glide path with an offset of 3.9°, starting from the rwy fwd. end and includes only a glide path and DME, but not a glide slope. Just to clarify a point, and clear up some terminology (as a CFII I am a bit anal when it comes to terminology ): GLIDESOPE = An antenna based vertical guidance associated with an ILS approach. The most sensitive of all vertical guidance due to the perfect alignment of the antenna with the runway. GLIDEPATH = A computed or antenna based vertical guidance associated with RNP, VNAV and LDA approaches. Works the same as an ILS glideslope but usually set to be less sensitive. APPROACH COURSE = The Lateral component of any approach, Precision or Non-Precision. OFFSET COURSE = An approach course set specifically and deliberately to be offset from the runway heading. Sounds almost like the phrase "Glidepath" was being used to refer to the offset course here... Just wanted to correct that Additionally, it's mentioned that there is no Glideslope at KEGE... In fact there is. It's referred to as a Glidepath rather than glideslope due to it's offset nature, but the LDA 25 approach does indeed contain vertical guidance: The green highlights here refer to the glidepath of the approach... It's a little confusing as "GS" is used and not "GP", but that's just standard. As you can see, following a Glidepath allows you to descend further before reaching your decision altitude (DA), rather than leveling off at the non-glidepath minumum descent altitude (MDA). Ok... I feel better now Link to comment Share on other sites More sharing options...
mark767 Posted August 30, 2015 Author Share Posted August 30, 2015 The chart is a little confusing because you are actually well above the GP until just before WASHI (which now that I look at it does coincide with the chart). My concern was more with the offset course here because it does not follow the chart at 246 degrees. Link to comment Share on other sites More sharing options...
wulfbindewald Posted August 30, 2015 Share Posted August 30, 2015 Additionally, it's mentioned that there is no Glideslope at KEGE... In fact there is. It's referred to as a Glidepath rather than glideslope due to it's offset nature, but the LDA 25 approach does indeed contain vertical guidance: Thanks for the clarification, Rob. Good to know that there is vertical guidance too. Now a correction would be highly appreciated....for safe landing in bad weather conditions ;-) . Wulf Link to comment Share on other sites More sharing options...
Dave_YVR Posted August 31, 2015 Share Posted August 31, 2015 Try flying the approach in something that doesn't rely on navdata to actually "fly the approach". The scenery is using the stock ILS, we see that there's no DME and it's set on a 3.0 degree gp vs 3.8. The issues raised here I think are from the Navdata more than anything. Link to comment Share on other sites More sharing options...
Edward Boyte Posted August 31, 2015 Share Posted August 31, 2015 Hello, Thanks for reporting this. We're currently fixing and testing this and will send out a hotfix very soon. Sorry for this bug! Link to comment Share on other sites More sharing options...
AKar Posted August 31, 2015 Share Posted August 31, 2015 Interesting. I just tried it again in the PMDG NGX. The setting for Mag vs True was default so maybe that is the issue. Anyway, I tried it again and there is a direrging path between the chart path and the path flown on the LOC. Turns out it still puts you on an offset ILS and pretty easy to land but in IMC conditions I don't think anyone would be very comfortable moving off the charted path with the terrain surrounding this airport. The setting in the airplane doesn't matter. The thing is that localizers and glideslopes (-paths) are physical arrays that point into a given true direction. The sim by default uses older magnetic variation, and many users have updated that to some newer, meaning that the magnetic headings may differ from the ones in charts. However, all the time the localizer of course points to the very same actual, physical, real direction, and this remains unchanged no matter how the real or the sim world magnetic variation changes. This is why these should be referred against true headings because that works regardless of any magvar mismatches. Note that the airplane following the loc goes over the same physical path regardless of any heading settings (just the displayed magnetic may be different). Anyways, that's not likely the source of this issue if it is a stock ILS indeed. I just remember seeing some scenery updates in which the ILS headings were forced to correct magnetic headings while the developer obviously had an old magnetic variation database - resulting in wrongly offset localizers! Link to comment Share on other sites More sharing options...
wulfbindewald Posted September 18, 2015 Share Posted September 18, 2015 Hello, Thanks for reporting this. We're currently fixing and testing this and will send out a hotfix very soon. Sorry for this bug! Is the KEGE hotfix still under preparation or do I miss any update? My FTXCentral does not indicate any available update. Wulf Link to comment Share on other sites More sharing options...
Jarrad Marshall Posted September 18, 2015 Share Posted September 18, 2015 G'day Wulf, It's still coming - FTX-C will let you know once it's out Cheers Link to comment Share on other sites More sharing options...
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