“FSTramp shows the ILS as it is contained in the scenery. The author of the scenery has probably not understood that the direction of the ILS is a true heading for FSX, but the magnetic heading for MSFS. That makes a difference of 18 degrees in CYVR.“
It's possible. Asobo might have decided to change a standard that hasn't changed since FSX, with no indication of that anywhere in the SDK. The thing that doesn't make any sense is:
- The ILS data file has two separate records for an ILS: heading and MagVar. Both are flagged as MANDATORY, the compiler won't even compile the scenery if you don't supply both.
So, what's would be the point of requiring *both* Heading and a MagVar, other than implying the Heading is meant to be True ?
So, I'm still convinced this is a bug, and FsTramp author is probably assuming the rule has changed, so he adapted is program to the bug. Want some proof ? See a post he made on MSFS forum back in March, during the Alpha ( FsNav user IS FsTramp author, you can see it in his profile )
https://forums.flightsimulator.com/t/all-ils-have-wrong-heading/49029Of course, back then he was entirely right saying the simulator had a bug if the default files really stored the headings as Magnetic:
The heading value in the BGL files is the magnetic heading. But this is wrong and does not correspond to the standard of FSX. All ILS heading must be entered as true heading
The are so many reasons why it doesn't make any sense to have Magnetic headings in the scenery database:
- The runways (and everything else that has an heading) use True heading too. This make it easier to align ILS and Runway, if they are supposed to be aligned. The only place in which you can choose to use True or Magnetic are the Approaches section.
- The Magnetic variation changes over time, if you store the headings as True ( as you should ), it would be enough to just update the MagVar .BGL, and all headings readout will now match current charts automatically, worldwide. Instead, by storing ILS data as Magnetic, when something change, you must update each and every .BGL for each and every airport that was affected.
- It defies the purpose of having a MagVar record for both the airport and the ILS.
So, what is probably happening here, is FsTramp author must have been frustrated the bug he reported hasn't been fixed, and the default ILS database is all Magnetic now, so he adapted his code to get around to it.
No problem, we can do the same, at least it would work until we'll get a clear answer from Asobo about this and if it's expected to change in the future.