Examples are 33,010, 37,010, 39,010. And this is with the Barometer set to STD. This isn't really a terrible problem but its always been an issue with my installations, even with FS2k, FS2k2, and now FS2k4. I assume this is normal and likely a simple flaw withing FS itself.Is this correct or is there another explanation?TIA!DougDell 8250 (3.06GHz/533FSB)1GB Rambus RAM120MB ATA 100 (7200 RPM)ATI Radeon 9700 Pro (Catalyst 4.5)Audigy 2 Sound (latest drivers)MS Force Feedback 2WindowsXP Pro (SP1)DirectX 9.0b

*** bumpety bump ***If I don't hear anything after this bump I'll let the question die.DougDell 8250 (3.06GHz/533FSB)1GB Rambus RAM120MB ATA 100 (7200 RPM)ATI Radeon 9700 Pro (Catalyst 4.5)Audigy 2 Sound (latest drivers)MS Force Feedback 2WindowsXP Pro (SP1)DirectX 9.0b

"If I don't hear anything after this bump I'll let the question die."You may want to give people a chance to wake up before giving up on a thread--you ask a very interesting question.I've never seen the problem, so I wouldn't call it an issue with FS Code. On the ground, I've seen the altimeter read higher than the actual ground level--and the reading is "off" exactly equal to the height of the cockpit above ground level. This gave me fits when I was writing my series of Autoland programs, as I was doing things when the aircraft alt and ground alt were equal. I finally had to settle on a variable called ON_GROUND, but sometimes it reads false when the aircraft hasn't fully settled. But I digress...Interesting question--curious to see what others say...-John

John,Thanks for the comment and suggestion to leave the question active. As I said this isn't a big issue for me just an odd curiosity. As you suggest, let's leave this one here and see what turns up :)Does your answer imply that you always see the exact commanded altitude on the PFD when you fly (e.g., 30,000, 33,000, etc.)?DougDell 8250 (3.06GHz/533FSB)1GB Rambus RAM120MB ATA 100 (7200 RPM)ATI Radeon 9700 Pro (Catalyst 4.5)Audigy 2 Sound (latest drivers)MS Force Feedback 2WindowsXP Pro (SP1)DirectX 9.0b

"Does your answer imply that you always see the exact commanded altitude on the PFD when you fly (e.g., 30,000, 33,000, etc.)?"I mostly fly steam gauge jets and props. What I see on the altimeter in the flight levels is sometimes accurate to the foot with some FDE's, more often it's accurate to +/- 3, 4 feet. I very rarely fly aircraft with PFD's.-John

I generally do not see what you are describing, although I do get occasional fluctuations up or down from the selected flight level. Is this with one aircraft or every aircraft in your installation? I imagine that it could be caused by the FDE of a certain aircraft, or many aircraft. To my knowledge the ones that I fly tend to stay on the numbers even though they may move a little bit now and then. Could it be something so simple as the weight of the aircraft causes a pitch up attitude thus showing a higher altitude? I do not know where on the aircraft the program determines the altitude of the aircraft so maybe a pitch up attitude could cause this. I am just throwing ideas out there since I really have no idea of what could cause this. Hopefully someone smarter than me has an answer for you.best Regards,Philip Olsonhttp://www.precisionmanuals.com/images/forum/supporter.jpg

>... Could it be something>so simple as the weight of the aircraft causes a pitch up>attitude thus showing a higher altitude? I do not know where>on the aircraft the program determines the altitude of the>aircraft so maybe a pitch up attitude could cause this.In speaking with a 777 pilot who has recently retired from United about a matter similar to this, he told me that on the real 777 the static ports are near the belly of the plane as opposed to up by the cockpit. He didn't specify its lateral position along the fuselage, but I imagine the engineers account for that factor in its placement for reporting accuracy (as near the mean CG as possible or such a small difference it doesn't much matter?).Where does FS take the measurement in your virtual airplane? Sounds like its taken in or from near the cockpit itself from what John has posted. Let's play around with that idea. If a really large airliner has 90 feet of fuselage forward of its CG (sheer supposition for argument's sake here - just a wild guess) and flies at a nose-up attitude of 3 degrees:tan(3) x 90' = 4.7 feet positive vertical displacementFurthermore, if the cockpit in this particular heavy is far above its CG you could have even more displacement and account for those 10 feet.However, shouldn't the autopilot put the CG wherever it needs to go so the instrument reads the correct altitude in flight? I can't imagine the autopilot puts the CG at the exact cruising altitude and lets the instruments flounder about up there all by themselves.It will take a person much smarter than I to answer this one. Just thought I'd talk/type out a couple of ideas (useful or not, I guess).Happy flying,Kevinhttp://forums.avsim.net/user_files/82438.gif