In the manual for RC4 there is a short introduction to the RVSM flight levels.It says that between FL180 and FL290, aircrafts with a heading between 0 degrees and 179 degrees must maintain odd flight levelse (FL 190, 210, 230 ...) while between 180 and 359 degrees it must be even flight levels (FL 180, 200, 220 ...).Then above FL290, aircrafts should cruise at levels in 4000 ft intervals, that is FL 290, 330, 370 ... and FL 310, 350, 390 ... respectively.Now I have also read that the latter changes to odd flight levels above FL290, and that makes sense too.BUT - then it talks about 6 new flight levels; FL 300, 320, 340 ... till FL410.Where do these flight levels come in when 1) The flight levels should be in 4000 ft. intervals and especially 2) all flight levels are odd above FL290 ??Hope that someone can sort this out for me.Thanks in advance./Nicolas

Please disregard; I found the answer myself.Previously there were only odd flight levels between FL290 and FL410. Today also the even flight levels (FL300 through FL400) have been included due to much bussier skies./Nicolas

Here's a bit more from the FAA:http://www.tc.faa.gov/acb300/techreports/D..._ATCA_10-03.pdf

Here's a bit more from the FAA:http://www.tc.faa.gov/acb300/techreports/D..._ATCA_10-03.pdf

In this FAA document on p. 2, do the arrows pointing to the right mean magnetic heading 0 - 179 and the ones pointing to the left 180 - 359 ?Thanks,Zach

Yes. Internationally there are a few jurisdictions that depart from the FAA hemisphere deviation, i.e. Israel, where the hemisphere is divided on an W-E boundary. A bit outdated but download Chapter 3 from http://www.faa.gov/library/manuals/aviatio...dures_handbook/and you'll find a chart where the hemisphere is defined with the letter M meaning magnetic on one of the figures.Generally all chart courses and flight governing rules except perhaps in polar regions due to magnetic problems with compass based references are declared as magnetic.You should also know that winds in ATIS are expressed in magnetic and in METARs are expressed as true.

In this FAA document on p. 2, do the arrows pointing to the right mean magnetic heading 0 - 179 and the ones pointing to the left 180 - 359 ?Thanks,Zach

Thanks, I think I got it now. I do have a follow-up though.I have noticed that when I receive potential collision warnings from RC, in many cases the altitude that is displayed (in red) next to the AI does not match the altitude that RC announces for the same aircraft and at least in some cases, these aircarft indeed seem to be at a different altitude than the one indiocated by RC. Thus far I have noticed these discrepancies only in Super Controller airspace. In all of these cases my altimeter was set to STD (29.92). Is this something that can be corrected or is this just one of the inherent inaccuracies ?Zach

Yes. Internationally there are a few jurisdictions that depart from the FAA hemisphere deviation, i.e. Israel, where the hemisphere is divided on an W-E boundary. A bit outdated but download Chapter 3 from http://www.faa.gov/library/manuals/aviatio...dures_handbook/and you'll find a chart where the hemisphere is defined with the letter M meaning magnetic on one of the figures.Generally all chart courses and flight governing rules except perhaps in polar regions due to magnetic problems with compass based references are declared as magnetic.You should also know that winds in ATIS are expressed in magnetic and in METARs are expressed as true.

I use a TCAS in several models and I have not noticed these altitude discrepancies. What are you using to display the AI altitudes?

Thanks, I think I got it now. I do have a follow-up though.I have noticed that when I receive potential collision warnings from RC, in many cases the altitude that is displayed (in red) next to the AI does not match the altitude that RC announces for the same aircraft and at least in some cases, these aircarft indeed seem to be at a different altitude than the one indiocated by RC. Thus far I have noticed these discrepancies only in Super Controller airspace. In all of these cases my altimeter was set to STD (29.92). Is this something that can be corrected or is this just one of the inherent inaccuracies ?Zach

Does this mean that if you change heading so that you're into the other hemisphere you have to change FL? I couldn't get ronzie's link to the FAA doc to work so apologies if this is covered in there.Iain Smith