FSX Magnetic variation

[2fst4u]

with GPS open, NO wind, in New Zealand/Wellington (where variation should be 023 degrees east, correct?)

if i set my autopilot (default cessna 172) to HDG 000 degrees, my GPS says my track is 000 (well, 360 actually) degrees aswell. shouldnt my track be 023?

i cant quite get my head around this. if it is wrong, how do i correct this?

ALSO, is there away to change bearing input for wind direction in weather from TRUE to MAG? because this is also annoying

[2fst4u]

hmm. on second though, can this please be moved to "General"? it isnt really technical, just complicated/advanced

[GlennAV8R]

QUOTE (2fst4u @ Feb 24 2009, 06:30 PM) <{POST_SNAPBACK}>

with GPS open, NO wind, in New Zealand/Wellington (where variation should be 023 degrees east, correct?)

if i set my autopilot (default cessna 172) to HDG 000 degrees, my GPS says my track is 000 (well, 360 actually) degrees aswell. shouldnt my track be 023?

i cant quite get my head around this. if it is wrong, how do i correct this?

ALSO, is there away to change bearing input for wind direction in weather from TRUE to MAG? because this is also annoying

Hi there

Your autopilot and GPS will both be using degrees Magnetic, the autopilot will derive this probably from the DI which needs to be set aginst the Compass. (Press the D key)
If your magnetic heading is 360 then your true hdg at Wgtn will be 022 true. I know there is a problem with how FSX calculates Mag Var. For example, if you set the wind up to be 180 True you get some incorrect figure for the Magnetic wind, cant remember off hand but it is way out in Wellington.

Glenn.

[2fst4u]

are you sure the GPS work off magnetic heading? i didnt think it was conncted to the other instruments. can someone confirm this?

EDIT: after some experimentation, GPS does work off magnetic heading (using its gps capabilities in real-life, do they know the variation for your position and correct accordingly?).



Paraparaumu-Wellington in real life is around 198.5 True . with zero wind, minusing 21 (the correct area variation) gives me a heading of 177 Magnetic (course of 177 because of zero wind). this takes me to near enough WGTN (not sure why it isnt exact, does FSX include magnetic deviation aswell?) and this is also the GPS heading shown to fly the course.

wow. this was doing my head in and i dont know why. i think it was because of FSX's automatic variation calculation when i bring up the kneeboard.

this brings me to my next question, is there a way to change the wind input to magnetic? or not because after clicking OK, the little summary in the 'weather' dialogue box gives me a MAG bearing, wheras before i click ok, the input i give is off by what ever the variation is (and therefore a TRUE bearing).

[GlennAV8R]

QUOTE (2fst4u @ Feb 25 2009, 07:41 AM) <{POST_SNAPBACK}>

are you sure the GPS work off magnetic heading? i didnt think it was conncted to the other instruments. can someone confirm this?

EDIT: after some experimentation, GPS does work off magnetic heading (using its gps capabilities in real-life, do they know the variation for your position and correct accordingly?).



Paraparaumu-Wellington in real life is around 198.5 True . with zero wind, minusing 21 (the correct area variation) gives me a heading of 177 Magnetic (course of 177 because of zero wind). this takes me to near enough WGTN (not sure why it isnt exact, does FSX include magnetic deviation aswell?) and this is also the GPS heading shown to fly the course.

wow. this was doing my head in and i dont know why. i think it was because of FSX's automatic variation calculation when i bring up the kneeboard.

this brings me to my next question, is there a way to change the wind input to magnetic? or not because after clicking OK, the little summary in the 'weather' dialogue box gives me a MAG bearing, wheras before i click ok, the input i give is off by what ever the variation is (and therefore a TRUE bearing).

Hi again
GPS will apply the local variation to give you a magnetic heading to steer. Magnetic variation in FSX is not correct, as in Wellington for example if you input the wind direction in degrees true, the resulting magnetic wind direction as diplayed (shift z) is incorrect. I dont know if there is a way of inputing in degrees magnetic or not. I believe the data that FSX uses for variation is quite out of date, resulting in the wrong variation being applied.

Glenn

[2fst4u]

great. thanks for clearing that up

[2fst4u]

disregard