Really dumb offset question:

[Raysot]

...trying to find the "Pressure Altitude" offset. When I change the Kohlman (Baro) setting from 29.xx to 29.yy (Or some other arbitrary value) which offset do I look at to get the new pressure alt? (Or is this derived?)

I can get Aircraft Altitude easy enough, but factor in millibars and I've no idea.

Any help is appreciated.

Ray Sotkiewicz

EllieSystems.com

[Pete Dowson]

...trying to find the "Pressure Altitude" offset. When I change the Kohlman (Baro) setting from 29.xx to 29.yy (Or some other arbitrary value) which offset do I look at to get the new pressure alt? (Or is this derived?)

Hmm. These terms tend to confuse me these days (old age? ;-) ), but if you mean the altitude read from the altimeter then it is in offset 3324. I found it by searching on the word "altitude" (You see, I don't actually remember all these offsets, I have to search for them too! ;-) ).

Note that it might be in feet or metres depending on the user's choice, also readable.

Regards

Pete

[hsors]

Hi Ray. Pressure Altitude (PA) is not related to any Kohlman window setting (except when set to 1013 hPa/29.92 inHg in which case altimeter will read PA). PA is by definition the altitude above MSL of an International Standard model at which air pressure is the same as the current measured air pressure.

There is no offset in FSUIPC3 giving directly pressure altitude. What you can do is recalculate it from ambient air pressure (0x28C8) and the ISA model formulas for pressure vs altitude. Alternatively you can approximate it from Altitude above mean sea level and current QNH (both available via FSUIPC)

For FSUIPC4, pressure altitude is directly available at offset 0x34B0

Hervé

[Pete Dowson]

Thanks Hervé! And a Happy New Year to you!

[LATER]

I've had a look can get the Pressure altitude for FS9 too -- in fact I'll do so in the next interim update, and put it in the same offset as for FSX! Odd no one has asked for it before.

Best Regards

Pete

[lefteris]

...Odd no one has asked for it before....

Pete-

I think everyone's calculating this instead... you're doing enough work as it is, so we don't ask for more if we can do it on our own :-).

[Pete Dowson]

...Odd no one has asked for it before....

Pete-

I think everyone's calculating this instead... you're doing enough work as it is, so we don't ask for more if we can do it on our own :-).

Oh, rightthanks everybody! ;-).

Actually it was easy to find and furnish, so it's provided now in FSUIPC3, for FS2002 (untested) and FS2004 (tested ok). Same offset as FSUIPC4's.

Best Regards

Pete