Hi all,

 

Newbie here. I was following Mike Ray's 700s tutorial and setup the Approach to use ILS 16L. The plane autolanded as the book says it would. However, I saw that the CRS selection on the MCP set at 182 instead of the approach plate's runway heading of 163

( I am using 1209 AIRAC). I thought that the CRS setting would match the runway heading? Setting the CRS to 163 would actually cause the plane to land on the aprons (btw this is what happen with the LD767 using its auto tune ILS feature, it would set the course to 163 and missed the runway, a bug?). Any help explaining this would be greatly appreciated.

 

Thanks

Hi all,

 

Newbie here. I was following Mike Ray's 700s tutorial and setup the Approach to use ILS 16L. The plane autolanded as the book says it would. However, I saw that the CRS selection on the MCP set at 182 instead of the approach plate's runway heading of 163

( I am using 1209 AIRAC). I thought that the CRS setting would match the runway heading? Setting the CRS to 163 would actually cause the plane to land on the aprons (btw this is what happen with the LD767 using its auto tune ILS feature, it would set the course to 163 and missed the runway, a bug?). Any help explaining this would be greatly appreciated.

 

Thanks

 

Welcome to the buggy world of FSX vs the real world of accurate charts.

 

There are quite a number of airports and their associated runway/headings that do not agree with the real world and when you use real world charts expecting FSX to conform with them you get surprises. In the case of KSEA, the runways were ladi out at a course of 180.3400 instead of the correct real world heading. This is NOT a PMDG issue nor even an AIRAC navdata issue, but rather an FSX design issue. The image below (using Airport Design Editor ADE) was taken directly from the FSX stock airport files for KSEA and you can see in the Heading (red outlined) in the info box that it was deliberately left at the aforementioned 180.3400.

 

http://www.mediafire...v1kz966ty4jl63y

 

Regards

 

Airport Design Editor (ADE): http://www.airportdesigneditor.co.uk/

Just curious, why would the CRS heading affect the ILS landing? I thought if the LOC is aligned with the runway centerline and you capture it, then you be lined up on the centerline regardless of CRS.

 

I don't have access to my sim right now, but does the Ray Smith KSEA fix it? http://library.avsim.net/esearch.php?CatID=fsxafcad&DLID=146102

Just curious, why would the CRS heading affect the ILS landing? I thought if the LOC is aligned with the runway centerline and you capture it, then you be lined up on the centerline regardless of CRS.

 

I don't have access to my sim right now, but does the Ray Smith KSEA fix it? http://library.avsim...cad&DLID=146102

 

Well, for me it did. If you want payware, get ORBX, that also fixes it for most.

Just curious, why would the CRS heading affect the ILS landing? I thought if the LOC is aligned with the runway centerline and you capture it, then you be lined up on the centerline regardless of CRS.

...

 

Good airmanship practice is to set the CRS heading, just in case you have to single channel A/P land instead of a dual channel Autoland. If the course setting does not match and at the last few moments, the Autoland disengages for whatever reason, it would be nice if the CRS heading agreed with the Localizer as in real life.

I am using ORBX scenery, so I assume that it is accurate. The moment I select ILS 16L and arm the approach the CRS is tuned to 182. The chart as rendered by Aivlasoft EFB also show a front course of 163 matching the airport. EFB uses data in AIRAC to construct the chart, so I also assume that it is correct. FSX has bugs for sure, but this is the NGX. This is important for me to understand, as I am suppose to read chart and use it correctly. So what do I miss?

 

Thanks

 

Welcome to the buggy world of FSX vs the real world of accurate charts.

 

There are quite a number of airports and their associated runway/headings that do not agree with the real world and when you use real world charts expecting FSX to conform with them you get surprises. In the case of KSEA, the runways were ladi out at a course of 180.3400 instead of the correct real world heading. This is NOT a PMDG issue nor even an AIRAC navdata issue, but rather an FSX design issue. The image below (using Airport Design Editor ADE) was taken directly from the FSX stock airport files for KSEA and you can see in the Heading (red outlined) in the info box that it was deliberately left at the aforementioned 180.3400.

 

http://www.mediafire...v1kz966ty4jl63y

 

Regards

 

Airport Design Editor (ADE): http://www.airportdesigneditor.co.uk/

I see. So even using ORBX does not fix the error? How do you fix it?

Just curious, why would the CRS heading affect the ILS landing?

 

I've read somewhere that it can affect affect LOC and B/CRS tracking.

For sure I can say that it's needed to set course for correct operations of HUD, ND in APP mode and localizer deviations scales on PFD.

 

 

Btw, http://forum.avsim.n...ndow-anomalies/ .

I am using ORBX scenery, so I assume that it is accurate. The moment I select ILS 16L and arm the approach the CRS is tuned to 182. The chart as rendered by Aivlasoft EFB also show a front course of 163 matching the airport. EFB uses data in AIRAC to construct the chart, so I also assume that it is correct. FSX has bugs for sure, but this is the NGX. This is important for me to understand, as I am suppose to read chart and use it correctly. So what do I miss?

 

Thanks

 

 

I see. So even using ORBX does not fix the error? How do you fix it?

 

edit> Since, I don't own any ORBX software packages for airports, I am somewhat surprised to hear that the ORBX packages for INDIVIDUAL airports do not also correct the issue for their software packages. In that case, I won't be wasting money on their software. With ORBX, you are paying a LOT of money for individual airports. The least you should be able to expect is a correction for this issue in their packages (depending on the airport of course).

 

edit> Now, that I read another post about MagVar and how it changes over time. It could be that the FS9/FSX airport data were pretty much correct at the time of their release, but since the magnetic pole shifts around, it causes the actual heading to vary. Obviously, the further north the airport is, the more error would be introduced over time. I was actually glad to read this as it simplifies a project I'm starting up.

 

Here's a link to a possible fix: http://www.aero.sors.fr/navaids.html

 

Regards

To the OP and the rest of the respondents:

 

In ADE the FSX default AFCAD correctly has the runways oriented to 183.4 degrees TRUE!!!!. FSX has a Mag variation built in at 17.3 degrees East where actual (2010) is 16.9 degrees. But the Magnetic heading either way is still 163^ which is exactly in agreement with my Nov 2011 charts for KSEA. I don't see the problem. The ILS course for 16L is 163 MAGNETIC and that is right down the center of the runway! Oftentimes with FSX default this may not be the case, however, so it has been recommended in several threads to always unselect "automatic course settting" in the FMC options menu. That way you will always be able to MANUALLY set the correct course.

 

As a further note: Many default FSX airports DO have one or more localizers set to the wrong true heading by a fraction of a degree and this can cause problems in autoland. Best to double check the course settings through ADE or a similar AFCAD disassembler before attempting a treacherous zero-zero autoland! It is a simple task to correct them to agree with the charts and then resave the airport scenery file.

 

PS: In the RW we always manually tuned even after auto-tuning option became available. The aircraft, however, will track the localizer correctly no matter what course is set but in a RW LIFR situation when a Miss is a distinct possibility you want all the course settings and headings to agree - no time for confusion at the DH. The only exception is when an immediate turn is required in the Miss procedure. Then the turn-to heading is preset on the MCP - again to avoid that last minute confusion during a balked landing.

Go here, have a read on & the follow the further link & update the Magnetic Declination file for FSX:

 

http://forum.avsim.n...or-fs9-and-fsx/

 

The guy also does NAVAID updates based on RL changes to the AIRAC in line with the monthly cycle - all free of charge to the FS community.

 

Runways do not move or swing in heading on the real earth surface - the only thing that moves & therefore changes the published CRS is the position of the Magnetic North Pole...as all Magnetic Headings & the published CRSes are referenced to this they change ever so slightly to.

 

As the guts of FSX are now approaching 7 years of age the amount of Magnetic Declination that has occurred is quite noticeable now.

 

The MAGDEC file is easy to install...& if you don't like the result it is straightforward to reverse. If my memory serves me well the fiile gives a MAGDEC based on 2010 which is much better than the default FSX value.

 

In addition - as Craig has pointed out you should still check the alignement of the LOCALISER BEAM heading with the RWY heading using something like ADE...you will soon find out that many of them are not in alignment....this bit is not related to the changes in magnetic declination.

In ADE the FSX default AFCAD correctly has the runways oriented to 183.4 degrees TRUE!!!!. FSX has a Mag variation built in at 17.3 degrees East where actual (2010) is 16.9 degrees. But the Magnetic heading either way is still 163^ which is exactly in agreement with my Nov 2011 charts for KSEA. I don't see the problem. The ILS course for 16L is 163 MAGNETIC and that is right down the center of the runway! Oftentimes with FSX default this may not be the case, however, so it has been recommended in several threads to always unselect "automatic course settting" in the FMC options menu. That way you will always be able to MANUALLY set the correct course.

Hi,

 

I don't think I understand. According to the chart, you are correct. However, if I manually set the front course in the MCP to be as you said 163, the plane will land on the apron. If I leave it to the NGX, the course is set at 182, and the plane lands right on the center line. This is my question. I have updated the mag variation, but the same thing still occur. From the chart produced by Aivlasoft EFB, I noticed that the mag variation is 17.5, so if I add it to 163, I have 180.5. So if I use this procedure: read the mag heading of the front course from the chart, then add/substract mag variation = the front course that I should manually set on the MCP?

 

Thanks

Good points, Steve. But the OP indicates that his course is auto-tuning to 182 which is closer to the TRUE heading instead of the Magnetic heading. True, the variation has changed since 2006 but as I mentioned the ADE shows a default TRUE heading of 183.4 and within FSX the runway headings correctly align with 163 degrees and this is already in agreement with the charts so the progression of variation in SEA must have been slow enough to still have everything in line. The FSX variation for KSEA is 17.3 E and the actual (last reading for US is 2010) is 16.9 E. So that little change does not account for the OP's reported inconsistency. And BTW, updating the Mag variation for the FSX environment will still not change the variation HARD-CODED into the AFCAD by Aces.

I guess our posts overlapped Vu. When variation is East then it is subtracted from the True heading to obtain the corrected Magnetic heading BUT the true heading is never used in the PMDG NGX since it is modeled only for Magnetic course headings (thus the limitation for polar flights in the FCOM) So the only way to figure this out is to disassemble the AFCAD and check the TRUE course of the runway as well as the localizer beam in the AFCAD. Something must be amiss. Again, I am using default KSEA AFCAD and everything is in sync.

 

Ah! Try this: Place a default 737 aircraft at the start of runway 16L using the FSX world airport menu. Unpause it and note the runway heading on the HSI. Now set Nav1 to the localizer frequency (110.30) and verify that the needle is in the center when you set ECAS to APP. This should be center regardless of your course setting. Localizers only send out one directional beam frequency (VOR transmitters send out 360 frequency variations corresponding to Magnetic course radials and require course tuning). If the needle is not centered then it has been incorrectly coded in the AFCAD and that is what is causing your problem. Doulble check that you are not setting VOR tracking in the MCP instead of APP. That's all I can think of since I am unable to duplicate your problem with NGX

And BTW, updating the Mag variation for the FSX environment will still not change the variation HARD-CODED into the AFCAD by Aces.

 

I never said it would - I did say this:

 

Runways do not move or swing in heading on the real earth surface - the only thing that moves & therefore changes the published CRS is the position of the Magnetic North Pole...as all Magnetic Headings & the published CRSes are referenced to this they change ever so slightly to.

 

Nor does it need to as the instrumentation within the NG takes info from the various NAVDATA files to correctly create the ND symbology like RWYs (all using MAG HDGS) & ILS frequency/course details & this is combined with reading the MAGDEC value for that particular part of the earths surface by cross referencing to the MAGDEC file to correctly represent magnetic headings on the NGX instrumentation.

 

I would suggest the LOC Beam is not aligned correctly with the RWY inside the AFCAD or scenery (OP has not indicated if this is stock or freeware/payware) & that once these two are checked in alignment the OP deselects the automatic CRS setting function in the NGX options.

 

Inside the AFCAD the LOC BEAM HDG must match the value set for the RWY HDG for things to marry up.

 

These will be TRUE NORTH values & other than ensuring that they match they are irrelevant as MAGDEC takes care of everything else inside FSX...unless the designer of the scenery has made a complete balls up & not matched his creation to the surface of the earth.

 

We are all making assumptions here & some screenies of the AFCAD file open in something like ADE might help clear things up.

A further thought, VU. It sounds like your magnetic variation is reversed! set as West instead of East but still the course setting should not matter on an ILS or Localizer approach, so this is a puzzler. Let's eliminate the possibilities one by one. If you have a copy of the FSX ADE program or a similar AFCAD disassembler use it view the KSEA aerodrome and click on the runway and it should bring up a box that contains the specifics of that runway including its TRUE orientation. Likewise the "feather" for the localizer when clicked should also bring up the TRUE course. It could be miscoded if you have 3rd party scenery. Localizers are set to TRUE Course NEVER Magnetic. Wrongly setting it to magnetic by the scenery designer could account for your problem.