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Guest yhfok

B744 Manual ILS Tuning -- Airports with Duplicate LOC F...

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Guest yhfok

Dear all,I know that the CDU format for manually tuning the ILS is XXX.XX/YYY, where XXX.XX is the LOC frequency and YYY is the inbound course. This is all good, except for airports with multiple LOC that share the same frequenct. My question is, for airports like KORD and KEWR where multiple LOCs share the same frequency. How can I specify with one to tune to?We were on approach from the East to KORD for the ILS 10 approach, which is on 111.10 MHz, but the FMC picked up the LOC for ILS 27L instead since it shares the same LOC frequency. As a result, we were unable to fly the ILS 10 approach.I have tried entering NNNN where NNNN is the LOC identifier, but the CDU returns a INVALID ENTRY message.Can anyone please advise how to solve this problem?Many thanks!!Best regards,Sunny Y. H. Fok

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Same localizer frequencies for both ends of runway is very common.I assume you have selected ILS10 as the approach, and you meant you picked up ILS28 approaching from the East (9R/27L changed to 10/28 last cycle). This is normal, in fact if you kept the nav tuned to an ils frequency as you flew cross county it would pick up every approach on that frequency as you flew by. What should happen is the annunciator will show ITSL until abeam the airport, then it will dissappear and when it returns it will show IMED (LOC IDs).Come to think of it, I think the annunciator over the PFD gets it's information from the FS9 scenery files. Sometimes the course it provides is different from the course that needs to be set for the approach in the 737, which is set manually. Anyway, it's display is only dependent on PMDG for giving it a spot to appear.


Dan Downs KCRP

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Guest yhfok

>I assume you have selected ILS10 as the approach, and you>meant you picked up ILS28 approaching from the East (9R/27L>changed to 10/28 last cycle). This is normal, in fact if you>kept the nav tuned to an ils frequency as you flew cross>county it would pick up every approach on that frequency as>you flew by. >>What should happen is the annunciator will show ITSL until>abeam the airport, then it will dissappear and when it returns>it will show IMED (LOC IDs).My bad, I meant ILS 28 when I said ILS 27L. We approached from the East, so the FMC picked up ILS 28 (ITSL) first and it never switched to ILS 10 (IMED).Same thing happened on departure from KEWR. We were on the MARINER 2 departure off rwy 4L, which requires ILS 4R DME (IEZA). ILS 4R and ILS 22L share the same frequency, so the FMC picked up the LOC for ILS 22L (ILSQ) instead, since that's the one closest to threshold 4L. We tried switching to ILS 4L (IEWR), but ILS 4L also shares frequency with ILS 22R. Again, the FMC picked up the one closest to our position, i.e. ILS 22R (IJNN). As a result, we weren't able to fly the required SID.In real life, the ILS at both ends of the runway are never on at the same time, so the real aircraft doesn't run into a similar problem. But unfortunately in FS, all ILS at a given airport are on 100% of the time regardless of the active approaches in use.>Come to think of it, I think the annunciator over the PFD gets>it's information from the FS9 scenery files. Sometimes the>course it provides is different from the course that needs to>be set for the approach in the 737, which is set manually.>Anyway, it's display is only dependent on PMDG for giving it a>spot to appear.I've tried manually tuning the frequency and OBS, but it still stays tuned to the first one that the FMC picks up. Luckily, everytime we encountered this problem, we were in VMC so we were able to proceed with a visual approach.The common thread is that all three times this has happened (KORD, KEWR, and KIAH), all three airport sceneries are made by Simflyers. Could this be a factor?

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Did you try shooting the approach regardless of what the annuciator was reporting? If not, give it a try. I believe the Simflyers stuff is pretty good, but it could be an error in their bgl files... I'd like to hear back that the approach works even if the ident feature is not good.


Dan Downs KCRP

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Use AFCAD to check out the localizers with the shared frequency at opposite ends. Make sure backcourse is not checked and save the file.By default, FS9 localizers have their backcourse enabled and at the default airports where the same LLZ frequency is shared at opposite runway ends you need to turn off the backcourse as it is in normal operations in the real world. This prevents your aircraft from capturing the wrong one.LLZ backcourse should only be enabled with authorized back course approaches and if not sure you can leave it on where the frequency is exclusive at one end of the runway.


Ron Ginsberg
KMSP Minnesota, Land of 10,000 Puddles
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I believe there is a known problem that airports built using FS2k2 style code (for example, SCASM) have a problem when ILS on both runway ends are on the same freq. Normally, the FS2k2 scenery will stop the display of "AFCAD" scenery (either default or addon AF2 file). The default or addon AF2 control the other aspects of the airport, including IIRC comms and services. But when the ILS are defined in the FS2k2 scenery and both runway ends share a freq, this seems to cause a conflict with the ILS definitions in the default or addon AF2. I think the correct solution is to remove all ILS entries from the FS2k2 scenery and use the AFCAD (that is, BGLCOMP) definitions for all ILS.I'm pretty sure that those simflyers airports were FS2k2 "upgraded" to FS9. I don't think that just unchecking the backcourse attribute in an AFCAD AF2 file and then installing that will fix it.I don't own those sceneries, but I see there is a fix file from simflyers, the readme suggests it will fix your problem:http://www.simflyers.net/aitraffic/files20...Trafficfix1.zipscott s..

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Guest yhfok

>Did you try shooting the approach regardless of what the>annuciator was reporting? If not, give it a try. I believe the>Simflyers stuff is pretty good, but it could be an error in>their bgl files... I'd like to hear back that the approach>works even if the ident feature is not good.What you've suggested would be an invitation for the FAA to come to your door and rip up your IFR licence. :(A bad identifier automatically means the approach is unusable, not only in real life (as it is illegal to do so), but in FS as well since that usually means the LOC/GS indications will be wrong.Since we could not properly identify the ILS, we shot a visual appr instead while leaving the ILS displayed in the PFD. We had to switch off the FD since the ILS indications were incorrect (reverse sensing LOC and no glidepath indications).

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Then I believe you have an issue with Simflyers.


Dan Downs KCRP

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