With all due respect Paul, I think it does affect the NGX. I flew into RW 25L at KLAS in the iFly737 and the FMC indicated the NAV1 freq was 111.75, Course 255. I set the NAV 1 and NAV 2 frequencies to 111.75. When I enabled the APP, the course heading automatically changed from 000 to 255 and the aircraft landed on the runway dead center. I flew the 737NGX and the FMC indicated the NAV1 freq was 111.75, Course 255. But, when I enabled the APP, the course heading changed to 257 and the aircraft was positioned for landing on RW 25L on the right side of the runway. With the APP enabled, I was unable to change the freq to 255 to get back on course. So it is strange to me that the FMC reads one thing and the course heading on the aircraft panel reads 257 on the PMDG737NGX. I used the latest Navigraph cycles. I found the same thing happened when trying to land on RW 25R with both aircrafts. I hope there will be a fix in SP1. Best regards,Jim Young

257 is the FSX default localizer course for KLAS 25L and 25R - this is what is hard-coded in the FSX airport scenery for the (unmodified) KLAS. Of course, the actual course in the real world is 255. The Navigraph AIRAC FMS database is based on the real-world current data, so it shows 255. In a real ILS receiver, the course dialed into the HSI or MCP really doesn't matter in terms of the aircraft's ability to accurately track the centerline. The ILS transmitter at the far end of the landing runway uses an array of directional antennas to generate two overlapping beams. The left side beam is modulated by a 90 Hz audio tone, and the right beam by a 150 Hz tone. When the two tones are equal in strength in the ILS receiver, it "knows" that the aircraft is aligned on the centerline, and drives the localizer needle to the center. If the 90 Hz tone is stronger, then the aircraft is to the left of centerline, and the needle moves right to indicate the direction to fly to get back on course. Likewise, if the 150 Hz tone is the stronger of the two, then the aircraft is to the right of center, and the needle moves to the left. The glideslope transmitter works in a similar fashion, though the actual radio frequencies are in the 300 MHz range, and the two beams are aligned vertically rather than horizontally - with the 90 Hz beam aligned above the glideslope center, with the 150 Hz beam aligned below. However, FSX, (and previous versions of FS) seem to act almost as if the ILS localizer is actually a VOR radial. A (real world) VOR operates on an entirely different principle than an ILS, even though both are tuned using the same NAV receiver, and both display on the same instrument. Suffice to say that when tracking a VOR radial, the specific course dialed in on the HSI or MCP does matter - and if the course is set incorrectly, the track over the ground will be offset to one side or the other of the desired track. This brings up a question: were you using the default FSX version of KLAS, or one of the commercial KLAS add-ons, in which the AFCAD has been corrected so that the localizers match the real-world values? And a question for Ryan: Does the localizer autotune "know" when the airport is based on a modified AFCAD, and will it use the modified localizer course in lieu of the FSX default? I would think so, since the modified AFCAD should be higher in the scenery database priority list, thus overiding the FSX default value.

Is there a way to know which airports this issue will be experienced at? It would be nice to not to have to test the airfield's ILS before each flight... Also, any insight if PMDG has logged this as a bug/issue? Thanks,Sam Kharey

Yes, if you have FS Commander. You use the "goto airport" menu function to center the map on the airport of interest. Then, zoom in, and click on the button to display the ILS localizers for all runways. If a localizer is offset due to incorrect data in the FSX scenery database, (or because the real-world localizer really is offset), then it will show very clearly on the FSC map. The map display will also show the default FSX localizer course associated with any ILS-equipped runway.

Gents, Data for the ILS target course are obtained directly from FSX (simconnect) which in turn reads them from the AFCAD file. Data include both the target course AND the magnetic deviation. I know of the FSDT KLAS issue. There is a mix up with mag var / front course there. I suggest you contact the vendor and ask them to sort it out (or rather to make their data compatible to the FS mag var tables on the spot). Not our problem.

257 is the FSX default localizer course for KLAS 25L and 25R - this is what is hard-coded in the FSX airport scenery for the (unmodified) KLAS. Of course, the actual course in the real world is 255. The Navigraph AIRAC FMS database is based on the real-world current data, so it shows 255. This brings up a question: were you using the default FSX version of KLAS, or one of the commercial KLAS add-ons, in which the AFCAD has been corrected so that the localizers match the real-world values?

According to my version of the default FSX w/Acceleration, the ILS for KLAS is 255 for 25L (open World/Map on FSX menu). Course heading 257 does not show up anywhere on my version of FSX. I do have FSDT KLAS installed and it shows 255 for 25L too. I disabled the FSDT version to get to the default version. So, not sure where you came up with heading 257 for the default. Best regards,Jim

Gents, Data for the ILS target course are obtained directly from FSX (simconnect) which in turn reads them from the AFCAD file. Data include both the target course AND the magnetic deviation. I know of the FSDT KLAS issue. There is a mix up with mag var / front course there. I suggest you contact the vendor and ask them to sort it out (or rather to make their data compatible to the FS mag var tables on the spot). Not our problem.

Like I stated before, the default and the AFCAD from FSDT reads 255 for RW 25L. Which vender are we suppose to contact? Navigraph? And, why does the iFly737 version show 255 for RW 25L and on the panel too? Just trying to get this clear for everyone. Best regards,Jim Young

According to my version of the default FSX w/Acceleration, the ILS for KLAS is 255 for 25L (open World/Map on FSX menu). Course heading 257 does not show up anywhere on my version of FSX. I do have FSDT KLAS installed and it shows 255 for 25L too. I disabled the FSDT version to get to the default version. So, not sure where you came up with heading 257 for the default. Best regards,Jim Like I stated before, the default and the AFCAD from FSDT reads 255 for RW 25L. Which vender are we suppose to contact? Navigraph? And, why does the iFly737 version show 255 for RW 25L and on the panel too? Just trying to get this clear for everyone. Best regards,Jim Young

No not Navigraph. The values included there are for display only. We ready what FSX reports and FSX reports what is in the AFCAD file in combination with the mag var coded there in combination with the "overlayed" mag var from magdec.bgl (thus the TRU/MAG conversion issue is not that simple). Some value coded in is incompatible with the other.

With all due respect Paul, I think it does affect the NGX. I flew into RW 25L at KLAS in the iFly737 and the FMC indicated the NAV1 freq was 111.75, Course 255. I set the NAV 1 and NAV 2 frequencies to 111.75. When I enabled the APP, the course heading automatically changed from 000 to 255 and the aircraft landed on the runway dead center. I flew the 737NGX and the FMC indicated the NAV1 freq was 111.75, Course 255. But, when I enabled the APP, the course heading changed to 257 and the aircraft was positioned for landing on RW 25L on the right side of the runway. With the APP enabled, I was unable to change the freq to 255 to get back on course. So it is strange to me that the FMC reads one thing and the course heading on the aircraft panel reads 257 on the PMDG737NGX. I used the latest Navigraph cycles. I found the same thing happened when trying to land on RW 25R with both aircrafts. I hope there will be a fix in SP1.

I have not flown the NGX into FSDT KLAS yet but here is what I found with a little research. The Real World Charts show hdg 255 for 25L, FSDT Scenery shows hdg 255, Default FSX shows hdg 255, BUT FS Commander 9 shows Hdg 257 as stated above. But since Dr. Vaos said he is aware of the problem at KLAS maybe he can enlighten us on which vendor is causing the problem at KLAS. I am willing to bet it is FSX causing the issue as stated above. But if you have FSDT KLAS Scenery then it is weird that they have not corrected this. As to why it works with the I-Fly and not the NGX that is something I would like to know the answer to as well. As for not being able to change the course read below. NGX Introduction Manual Page 56

SET FSX LOC CRS: When it comes to navigation data, FSX has an inherent weakness in that data related to ILS/LOC stations is hard coded into the simulator and is not updated to keep it current with the normal magnetic shift. The end result is that the localizerfinal approach course in the FSX world will sometimes vary from the real world. Since many users are also using real-world navigation charts, this can create some confusion and can also create problems if the LOC course is not correctly set to match the FSX hard-coded information. (The airplane cannot fly the localizer properly if the CRS knob is set incorrectly.) To compensate for this, we recommend setting this option to ON, and we will read the appropriate FSX localizer course and adjust the setting for you, thus saving you time and frustration.

I only see 3 possible options when you encounter a problem like this. 1) If you are using the Stock FSX Airport Scenery you can get an updated AFCAD. There are many free ones available in the AVSIM Files section. 2) If you are using Payware Airport Scenery you can contact the Vendor for a solution. 3) If option 1 and 2 are not possible then you will just have to hand fly it in manually.

Thanks Paul for the info. It looks like "SET FSX LOC CRS" is the solution for PMDG aircraft. Others in this thread have mentioned this too but I appreciate the effort to get the quote from the PMDG Manual and put it here for all to see. Personally I try to stay away from the Autoland feature and manually bring the aircraft in for a landing. However, I can see a problem if visability is down to near zero and you're trying to land IFR. The wrong course setting could easily terminate a bunch of virtual passengers if you aren't paying attention just before touchdown. Best regards,Jim Young

Question: Is anyone seeing this at DEFAULT FSX airports? If so I need to know where. We can't control what addon companies are putting in their local magvar. That's the problem with FSDT KLAS - the local magvar in their AFCAD is 2 degrees off from the world magvar there - that's why the NGX calculates 257 instead of 255. If they set their local magvar to the same as the world one it'd work just fine.

Question: Is anyone seeing this at DEFAULT FSX airports? If so I need to know where. We can't control what addon companies are putting in their local magvar. That's the problem with FSDT KLAS - the local magvar in their AFCAD is 2 degrees off from the world magvar there - that's why the NGX calculates 257 instead of 255. If they set their local magvar to the same as the world one it'd work just fine.

I just wanted to state I turned off "SET FSX LOC CRS" in the Equipment section and was able to set the 255 course manually and I landed dead center. Ryan, if the local magvar in the FSDT KLAS AFCAD is 2 degrees off, why does the FMC state course 255 on the Approach page and then course 257 is placed on the panel when the APP is enabled? And, why, when I manually set the course to 255 with SET FSX LOC CRS to off, did the 737 NGX place me dead center on the FSDT KLAS 25L? If I had manually entered 257, I would have been 2 degrees to the right of the runway. Perhaps FSDT updated their AFCAD and you did not have the current one? And, why, when I flew the iFly 737 as discussed earlier, was I able to land dead center on runway 25L after enabling the APP and the course on the panel was 255? So far I haven't seen this except at KLAS and I land at a lot of default airports. I haven't seen it at any other FSDT airport so far and I own most of them. Just KLAS. In any case, I can handle it by setting the course manually in the future. Best regards,Jim Young

would have been 2 degrees to the right of the runway. Perhaps FSDT updated their AFCAD and you did not have the current one?

I Think people are getting confused on what AFCAD and AIRAC files are and what they actually do. AFCADs are files that store the Sceneries in FSX, they contain all the NDBs VORS, ILS, RWYs, Taxiways, Terminals and Buildings. AIRACs are files that update your FMC with the latest SIDs, STARS, and procedures and a new one comes out every month to cover any changes that were made at real world airports. PMDG is in the Aircraft Business, FSDT is in the Scenery Business and Navigraph is in the Navigation Business. The NGX FMC just uses the information from AFCAD and AIRAC files and that is it. A good example is the Movie Die Hard 2 at Washington Duells (KIAD) Yeah I know it is a movie and not sure if they could actually do that in the real world. But do you remember how the terrorists changed the ILS and made the plane fly into the ground? It was not the pilots or Planes fault. The aircraft was using the information currently available to it. Same thing applys here. So whether Microsoft desgined the Airport or a Payware Developer made the airport, if there is a error in the scenery then the only one that can fix it is the developer. Or if your lucky some freelancer was kind enough to take the time and make a new AFCAD to correct the problem. Same thing goes for the AIRACs files and it has happened before. If they screw up an airport and have you flying donuts around it that is their error and they are the only ones that can fix that.

HelloIf you also use Mytraffic X be sure to check that you have disabled the MT afcad for KLAS "BR2_KLAS.bgl" as this afcad has 257 for 25L

Hello If you also use Mytraffic X be sure to check that you have disabled the MT afcad for KLAS "BR2_KLAS.bgl" as this afcad has 257 for 25L

That never occured to me to think about that, I wonder if that could be the culprit.

HelloHaving disabled the MT afcad and run the FScommander D/Base builder, FScommander now shows that the course is 257 taken from \FSX\Scenery\0202\scenery\APX17190.bgl which is a standard FSX file.However on starting up FSX and going to KLAS a check of the FSX map shows 255.Where is the FSX map getting this data from if not APX17190.bgl.I have no third party scenery installed for the usa at all?

Using Peter Dowsons "makerunways" I have extracted this info, don't know if it helps. Enabled Aerosoft US Cities afcad just for those who maybe using that afcad. FSDT KLAS Secondary ILS: ILAS 110.30 Hdg: 269.9 , Flags: GS DME BC "ILS/DME 25R" *** Runway *** KLAS0071 Lat 36.076378 Long -115.169899 Alt 2180 Hdg 75 Len 14495 Wid 150 *** Runway *** KLAS0252 Lat 36.076416 Long -115.120705 Alt 2180 Hdg 255 Len 14495 Wid 150 ILS 110.30, Flags: GS DME BC Runway 7R/25L centre: N36:04:25.1152 W115:08:37.0012 2180ft Start 7R: N36:04:25.0828 W115:09:39.0908 2180ft Hdg: 89.9T, Length 10512ft Computed start 7R: Lat 36.073627 Long -115.161445 Start 25L: N36:04:25.1800 W115:07:34.9829 2180ft Hdg: 269.9T, Length 10512ft Computed start 25L: Lat 36.073658 Long -115.125771 Hdg: 89.940 true (MagVar 15.000), Asphalt, 10512 x 150 ft Secondary ILS ID = IRLE Secondary ILS: IRLE 111.75 Hdg: 269.9 , Flags: GS BC "ILS 25L" *** Runway *** KLAS0072 Lat 36.073627 Long -115.161446 Alt 2180 Hdg 75 Len 10512 Wid 150 *** Runway *** KLAS0251 Lat 36.073658 Long -115.125771 Alt 2180 Hdg 255 Len 10512 Wid 150 ILS 111.75, Flags: GS BC FSX"ILS 25L" *** Runway *** KLAS0072 Lat 36.073620 Long -115.161469 Alt 2180 Hdg 75 Len 10512 Wid 150 *** Runway *** KLAS0251 Lat 36.073650 Long -115.125793 Alt 2180 Hdg 255 Len 10512 Wid 150 ILS 111.75, Flags: GS BC Runway 1R/19L centre: N36:05:10.8560 W115:09:38.0012 2180ft Start 1R: N36:04:28.4518 W115:10:02.2603 2180ft Hdg: 24.9T, Length 9783ft Computed start 1R: Lat 36.074177 Long -115.167533 Offset Threshold primary: 491 feet Start 19L: N36:05:53.2278 W115:09:13.7406 2180ft Hdg: 204.9T, Length 9783ft Computed start 19L: Lat 36.098522 Long -115.153573 Offset Threshold secondary: 878 feet Hdg: 24.860 true (MagVar 15.000), Asphalt, 9783 x 150 ft *** Runway *** KLAS0012 Lat 36.074177 Long -115.167534 Alt 2180 Hdg 10 Len 9783 Wid 150 *** Runway *** KLAS0191 Lat 36.098522 Long -115.153572 Alt 2180 Hdg 190 Len 9783 Wid 150 Runway 7L/25R centre: N36:04:34.7687 W115:08:43.1699 2180ft Start 7L: N36:04:34.7039 W115:10:08.6589 2180ft Hdg: 89.9T, Length 14495ft Computed start 7L: Lat 36.076305 Long -115.169921 Offset Threshold primary: 2139 feet Start 25R: N36:04:34.8335 W115:07:17.6809 2180ft Hdg: 270.0T, Length 14495ft Computed start 25R: Lat 36.076344 Long -115.120728 Offset Threshold secondary: 1397 feet Hdg: 89.950 true (MagVar 15.000), Asphalt, 14495 x 150 ft Secondary ILS ID = ILAS Secondary ILS: ILAS 110.30 Hdg: 270.0 , Flags: GS DME BC "ILS/DME 25R" *** Runway *** KLAS0071 Lat 36.076305 Long -115.169922 Alt 2180 Hdg 75 Len 14495 Wid 150 *** Runway *** KLAS0252 Lat 36.076344 Long -115.120728 Alt 2180 Hdg 255 Len 14495 Wid 150 ILS 110.30, Flags: GS DME BC Aerosoft US CitiesRunway 7R/25L centre: N36:04:25.1152 W115:08:37.0592 2180ft Start 7R: N36:04:25.0504 W115:09:39.0552 2180ft Hdg: 89.9T, Length 10512ft Computed start 7R: Lat 36.073627 Long -115.161468 Start 25L: N36:04:25.1476 W115:07:35.0631 2180ft Hdg: 269.9T, Length 10512ft Computed start 25L: Lat 36.073658 Long -115.125794 Hdg: 89.940 true (MagVar 15.000), Asphalt, 10512 x 150 ft Secondary ILS ID = IRLE Secondary ILS: IRLE 111.75 Hdg: 269.9 , Flags: GS BC "ILS 25L" *** Runway *** KLAS0072 Lat 36.073627 Long -115.161469 Alt 2180 Hdg 75 Len 10512 Wid 150 *** Runway *** KLAS0251 Lat 36.073658 Long -115.125793 Alt 2180 Hdg 255 Len 10512 Wid 150 ILS 111.75, Flags: GS BC Runway 1R/19L centre: N36:05:10.8560 W115:09:38.0012 2180ft Start 1R: N36:04:28.4518 W115:10:02.2603 2180ft Hdg: 24.9T, Length 9783ft Computed start 1R: Lat 36.074177 Long -115.167533 Offset Threshold primary: 491 feet Start 19L: N36:05:53.2278 W115:09:13.7406 2180ft Hdg: 204.9T, Length 9783ft Computed start 19L: Lat 36.098522 Long -115.153573 Offset Threshold secondary: 878 feet Hdg: 24.860 true (MagVar 15.000), Asphalt, 9783 x 150 ft *** Runway *** KLAS0012 Lat 36.074177 Long -115.167534 Alt 2180 Hdg 10 Len 9783 Wid 150 *** Runway *** KLAS0191 Lat 36.098522 Long -115.153572 Alt 2180 Hdg 190 Len 9783 Wid 150 Runway 7L/25R centre: N36:04:34.9955 W115:08:43.8844 2180ft Start 7L: N36:04:34.9307 W115:10:09.5535 2180ft Hdg: 89.9T, Length 14495ft Computed start 7L: Lat 36.076370 Long -115.170120 Offset Threshold primary: 2139 feet Start 25R: N36:04:35.0926 W115:07:17.0533 2180ft Hdg: 270.0T, Length 14495ft Computed start 25R: Lat 36.076408 Long -115.120926 Offset Threshold secondary: 1397 feet Hdg: 89.950 true (MagVar 15.000), Asphalt, 14495 x 150 ft Secondary ILS ID = ILAS Secondary ILS: ILAS 110.30 Hdg: 270.0 , Flags: GS DME BC "ILS/DME 25R" *** Runway *** KLAS0071 Lat 36.076370 Long -115.170120 Alt 2180 Hdg 75 Len 14495 Wid 150 *** Runway *** KLAS0252 Lat 36.076408 Long -115.120926 Alt 2180 Hdg 255 Len 14495 Wid 150 ILS 110.30, Flags: GS DME BC

I just wanted to state I turned off "SET FSX LOC CRS" in the Equipment section and was able to set the 255 course manually and I landed dead center. Ryan, if the local magvar in the FSDT KLAS AFCAD is 2 degrees off, why does the FMC state course 255 on the Approach page and then course 257 is placed on the panel when the APP is enabled? And, why, when I manually set the course to 255 with SET FSX LOC CRS to off, did the 737 NGX place me dead center on the FSDT KLAS 25L? If I had manually entered 257, I would have been 2 degrees to the right of the runway. Perhaps FSDT updated their AFCAD and you did not have the current one? And, why, when I flew the iFly 737 as discussed earlier, was I able to land dead center on runway 25L after enabling the APP and the course on the panel was 255? So far I haven't seen this except at KLAS and I land at a lot of default airports. I haven't seen it at any other FSDT airport so far and I own most of them. Just KLAS. In any case, I can handle it by setting the course manually in the future. Best regards,Jim Young

Jim, APPROACH REF FMC page info comes from the navdata, this is the real life data that is updated every month by Navigraph. Resides in the FSX\PMDG\NAVDATA and SIDSTARS folders. SET FSX LOC CRS ON setting comes from directly querying the BGLs through SimConnect. SET FSX LOC CRS OFF uses whatever you manually input into the MCP CRS window. The navdata and the FSX course are not always the same due to FSX being 6 years old and the real life magnetic variation changes. We had to do it this way otherwise you get major mismatches.

HelloHaving disabled the MT afcad and run the FScommander D/Base builder, FScommander now shows that the course is 257 taken from \FSX\Scenery\0202\scenery\APX17190.bgl which is a standard FSX file.However on starting up FSX and going to KLAS a check of the FSX map shows 255.Where is the FSX map getting this data from if not APX17190.bgl.I have no third party scenery installed for the usa at all?

It's the two different applications of magnetic variation... airports have their own and so does the world as a whole. The local variation at LAS is 2 degrees off from what the world variation below that same spot is. That's where we think the mismatch happens.