Hello,Is there a way to prevent Active Sky X from altering the air pressure during the flight ?The background for this is that I am using Radar Contact 4 and RC seems to be very sensible about altiude. If I do not continously press teh B key while leveled (below FL180 of course) it will soon complain about my altitude bacause the pressure has changed. The only solution I could imagine is to fix the pressure during the flight. Other solutions will be welcome as well.In reallity one would be able to use the set pressure for at least 30 Minutes or 100mi, however with ASX & RC4 I need to constantly press the "B" key to adjoust the altimeter.Cheers,Gaston

Hi,The resulting air pressure is influenced by FSX interpolation and depiction, some of which is problematic and can cause unexpected transitions. Our data injected is as per station reports.Keeping a 'fixed' average pressure reading, or preventing variation from departure area of a certain max amount may help this, and is worth a look at for an potential enhancement feature in the next ASX revision. Please send us a suggestion to tell-us AT hifisim.com so we can log this.One thing to note however, is that it is common practice in real life to have varying pressures in different areas, especially when crossing into new air masses or through frontal zones, and thus when IFR ATC will always give you the local altimeter when you enter a new sector or have you indicate that you've received current local ATIS (for airport departure/arrival operations). It is the PIC's responsibility to adjust the altimeter appropriately so that all aircraft are flying at the expected altitudes and have appropriate separation. Changing the altimeter many times during a typical IFR flight is pretty common.Best,

The latest release of FSUIPC v 4.25 has a pressure smoothing function specifically to address this FSX issue. I've been testing it a lot recently and it works very well with ASX. Try that and you should find a far more stable pressure situation.

Thank you for the quick reply,>The resulting air pressure is influenced by FSX interpolation>and depiction, some of which is problematic and can cause>unexpected transitions. Our data injected is as per station>reports.Yes, my appologies here for this. I never ghad the problem before using ASX but this was due to the fact that exactely at that time I was doing short range flights with a CRZ altitude of 17000. For "normal" flights RC4 usually requests level changes before I do actually reach the previous level. I have now tried without ASX started and used real conditions but without updates in FSX. The same problem occurs here. I hit the "B" key to set the correct value, hittign it again about 10 seconds later gave such a difference that the altitude changed by 160 feets. 2 such changes and RC4 would complain as it complains at +/-300ft by default.>Keeping a 'fixed' average pressure reading, or preventing>variation from departure area of a certain max amount may help>this, and is worth a look at for an potential enhancement>feature in the next ASX revision. Please send us a suggestion>to tell-us AT hifisim.com so we can log this.Will do after some more thinking.>One thing to note however, is that it is common practice in>real life to have varying pressures in different areas,>especially when crossing into new air masses or through>frontal zones, and thus when IFR ATC will always give you the>local altimeter when you enter a new sector or have you>indicate that you've received current local ATIS (for airport>departure/arrival operations). It is the PIC's responsibility>to adjust the altimeter appropriately so that all aircraft are>flying at the expected altitudes and have appropriate>separation. Changing the altimeter many times during a>typical IFR flight is pretty common.Yes, you are absolutely right and that is what I said also in my initial post. However usually one would expect (special conditions excluded) that no more then 2 changes per hour or 100nm would be necessary in average, an yes possibly at sector change. Here with RC4 adjustments are required on seconds base to prevent RC from complaining.While fixing the pressure would be an easy way to fix the problem, thinking a bit more in detail its more an RC4 problem. The controller does see the flight level through the secondary radar in real world, and this is in turn the altitude measured by the aircraft and send to the secondary radar. So independent of what my real altitude ist the controller (here RC4) should use the altitude displayed on my gauge and that one was correct. Here the scenario: Aurcraft leveled at FL170 which is the assigned altitude by RC4. Now RC4 complains about the wrong altitude, the gauge however shows 17000 as the altitude is constantly maintained. As RC4 is the controller he should also see 17000 as by the secondary radar. Only when I press teh B Key now to select the real pressure the gauge will change the altitude as this is a jump and the correct altitude need to be aquired again.I will post this to RC4 support as well.Many thanks so far,Gaston

>The latest release of FSUIPC v 4.25 has a pressure smoothing>function specifically to address this FSX issue. I've been>testing it a lot recently and it works very well with ASX. Try>that and you should find a far more stable pressure>situation.Thank you for pointing me to this. So far I have only the unregistered FSUIPC installed which came with RC4, but I will consider paying for the full version now.Gaston

Update:I have now installed the full version of FSUIPC and done some further tests. First of all, yes the smoothing function helps for the pressure bumping.Now that the pressure is more stable it showed that the problem source is not the waether at all. For some reason there is a difference between the QNH and thus altitude as seen by RC4 versus the one seen by the PMDG 747.I will now go on checking which one of both products is causing the problem. Whils ASX was never really assumed to be the cause I did assume it could help solving it. Niw it is completely out of line of sight as the problem is an offset of the QNH between RC4 and PMDG/FSX.Gaston