HiHad my first PMDG B737-700 longish haul flying on VATSIM yesterday and noticed that my altitude and that reported by VATSIM were different (by 400'). I also noticed this on another aircraft also flying VATSIM in my vacinity and reporting FL370 but showing in VATSIM as FL374.As I went through the transition layer, I selected STD air pressure, which I would have thought would have corrected for any air pressure anomolies. Is it normal to show a difference between the selected flight level in the cockpit and that reported by VATSIM?

When flying on VATSIM, you may notice discrepancies like this. I think that somewhere in there the local altimeter setting is used to report altitude to VATSIM even though you've set your altimeter to standard.The key thing is to be sure that you did actually set your altimeter to STD, and then everybody else will be set the same way, so you shouldn't hit anyone.

Thanks Timothy,I suspect that you are correct. I have noticed that when changing to STD air pressure (at the transition alitude) there is no change to the altitude readout. I would have expected to see a change.It only becomes awkward (well - more embarassing really) when you file for say FL350 and ATC reports you at some other level and there seems to be nothing that you can do about it. Thanks for the response (and your great tutorials by the way!)

The controller should know this... :) If I'm not mistaken it is a small "bug" which is being fixed by a minor ASRC patch. But don't ask me where the difference comes from... (I think it has been explained on the VATSIM forum once) :) Bye, Luca

>I have noticed that when>changing to STD air pressure (at the transition alitude) there>is no change to the altitude readout. I would have expected to>see a change.STD air pressure is 2992. Thus, if you have not changed your local air pressure from 2992, there will be no change. However, if you do change it to a local air pressure which might be 2886, then you will notice a change.