Changing ILS Frequency in FMC

[Heronjr 3]

Hi Kyle,

My scenery and aircraft are updated monthly to the last Navigraph AIRAC (1706) and all the OMDB scenery frequencies are the same of the real world published charts, as it is a high quality commercial add on (Fly Tampa  Dubai Rebooted). 

I repeat, the problem is,  when coming left downwind, as the aircraft turns base to 12R , it captures the letters of runway 12L (IDBR) but maintains the frequency 109.50, which is the correct 12R frequency, thus provoking a mismatch and spoiling the approach. You can clearly see the wrong letters on PFD/MFD

Otherwise, if I come from the right downwind, i.e. using other STAR, the aircraft correctly captures the ILS 12R and does the approach as programmed. 

I'll rephrase the question: Why the aircraft picks another runway data if the FMC is already programmed to the original one? 

Does this happens in real world? If so, how to avoid?

Please see the BUBI1B STAR (page 10-2) and the ILS approaches ((pages 11-1 to 11-2) at:

http://vau.aero/navdb/chart/OMDB.pdf

Try this approach with a QOTS programing it to land on 12R using this star. 

Best

[scandinavian13 5,192]

10 minutes ago, Heronjr said:

My scenery and aircraft are updated monthly

Your scenery is not updated monthly. This is false.

10 minutes ago, Heronjr said:

You can clearly see the wrong letters on PFD/MFD

This is data reported by the sim, itself, not the aircraft or the aircraft's database. In other words, our code is reading what your sim is providing to it.

11 minutes ago, Heronjr said:

Why the aircraft picks another runway data if the FMC is already programmed to the original one? 

I answered this in my earlier post: your aircraft data (real world), does not match up with the sim (not real world). Update the sim.

12 minutes ago, Heronjr said:

Does this happens in real world? If so, how to avoid?

It does not. They ensure their data matches. You, on the other hand, have not.

Check by doing the following:

Load the sim, and go to an airport where you are seeing this issue. Open the simulator's map. Click on one of the runways where you are seeing the issue and observe the data. I'm willing to bet it's the wrong data.

[downscc 1,327]

11 hours ago, Heronjr said:

Normally, this is a situation in which you're preoccupied with other procedures for safe landing and then, at that point, you have to quickly peel a pineapple!

This is why the crew does a pre-arrival briefing.  The approach is studied, and in the sim you can verify frequencies on the platform map, missed approach planned, alternates, expected arrival, and anything unusual.  Good time to start this is before TOD before it gets busy.

[Heronjr 3]

Sorry, you're correct Kyle, my scenery is not monthly updated. Only the aircraft and tools which have Navdata contracted.

My FSX Map of FlyTampa OMDB says for ILS data:

12L - IDBL - 110.10

12R - IDBE - 109.50

30L - IDBW - 111.30

30R - IDBR - 110.90

Which are exactly the numbers/letters shown in the 2017 published approach plates on the link I gave you.

The change I saw while turning base was on the identifiers (IDBE to IDBR) but the frequency on NAV/RAD was still 109.50, however, the approach failed.

In order to organize our discussion, at that time, I put the navigation on HDG, made a turn, rebuilt the approach on DEP/ARR page, and intercepted the localizer 30R from the right and it did work, proving that the scenery frequencies were the same as the aircraft frequencies.

Best

[downscc 1,327]

12 minutes ago, Heronjr said:

The change I saw while turning base was on the identifiers (IDBE to IDBR) but the frequency on NAV/RAD was still 109.50, however, the approach failed.

You had IDBR on the PFD when the frequency was set to IDBE 109.5?? That is unexpected.  The FlyTampa scenery still has the correct frequencies for the ILS. I cannot think of any way for IDBR to appear on your PFD.

[Heronjr 3]

Dan,

Yes, IDBR was set to IDBE and I lost data for approach. Before turning base, I could see the IDBE, the LOC and the GS for the assigned runway 12R. This has happened to me twice on OMDB and once at LatinVFR KMIA.

My guess is I was intercepting the localizer on LNAV, and there is a warning on FCOM about this. (NP.21.47), but I'm not sure if this is exactly the case.

I will make some tests on this circuits and see if using HDG to join works.

Best,

[icemarkom 59]

Suggestion: fly the approach with some other airplane, and see what happens. That should tell you for sure whether it's your simulator, or a bug in PMDG aircraft.

[downscc 1,327]

13 minutes ago, Heronjr said:

Yes, IDBR was set to IDBE

You lost me here.  Two different ILS frequencies, you cannot set one to the other.

[Heronjr 3]

I have just flew the approach 12R to OMDB using BUBI1B star.During the downwind leg, it correctly tuned the ILS 12R on 109.50 IBDE (as always).

Then, before the base left turn, I deactivated LNAV and did the turn using HDG. It captured the LOC and G/S like a charm. You can leave VNAV as you wish, or FLCG.

Juergen, try your fly to OMDB turning to final using HDG instead of LNAV.

Please, read the warning in FCOM (NP 21.47). I don't know if that's the answer. Don't think it's a bug.

Best,

[Budbud 227]

Hi,

The ILS autotune has nothing to do with the roll mode used. It just look up in the nav database the frequency and course corresponding to the ILS selected in the DEP ARR page of the CDU.

The warning in the FCOM just refers to the fact that the interception of the localizer may not be achieved when using LNAV. But in now case it refers to a loss of the ILS data.

[Heronjr 3]

14 hours ago, Budbud said:

Hi,

The ILS autotune has nothing to do with the roll mode used. It just look up in the nav database the frequency and course corresponding to the ILS selected in the DEP ARR page of the CDU.

The warning in the FCOM just refers to the fact that the interception of the localizer may not be achieved when using LNAV. But in now case it refers to a loss of the ILS data.

In this case, I'll do some more tests using LNAV and HDG to join LOC at airports with parallel ILS runways and, if the frequency problem persists, open a ticket I will.

Best,