Hello,My cabin pressure is a bit screwy with my -800 model. It seems to work fine until climbing through about 23,000ft at which point my cabin pressure continues to climb to about 11,000-12,000ft, where it remains throughout the rest of the high altitude portion of my flights. It should of course climb to about 8,000ft and remain there through the rest of the flight until reaching the correct point during descent. Attached is a screenshot illustrating my problem. It was taken at 37,000ft. I have pneumatics set properly with both packs on and the center isolation valve positioned to AUTO. Both engine bleed air valves are open and duct pressure appears to be in the normal range. I do not recieve any warnings or error annuciations on the panel. On the real aircraft, PAX oxygen masks would automatically deploy at the 10,000ft cabin altitude mark :)I have this problem with every flight I make. I have the correct cruising and landing altitudes dialed in and cabin pressure seems fine until climbing above the 23,000ft mark as I mentioned.Is this a known issue? Any suggestions as to what's going on? Thanks very much.http://forums.avsim.net/user_files/76023.jpg

I just wanted to reiterate that everything works fine below 23,000ft, pressurization readings are normal at takeoff and landing.

Q: wats wrong with the cabin alt or rate?

Hi there,If you will reference the attachment above you will notice that the cabin altitude on the pneumatics panel (inner dial index, short hand needle) indicates about 12,000ft. On the real aircraft this should read no greater than 8,000ft at all times. A cabin altitude of 10,000ft or greater would be considered an emergency condition requiring deployment of PAX oxygen. :)

Ah! I was wondering why that oxygen mask keeps popping down from the ceiling tiles in the basement everytime I get an above 10,000' reading...LOL:-lol Tom Stewart

I know that the Cab Alt. have to be at 8000 about, but it depents on the PSI in the cabin...normaly it should be at about 8.9 PSI or something.

Hypoxia central :)

Yes, cabin altitude SHOULD be reading around 8,000ft instead of the 12,000ft mark I'm experiencing. Does your cabin altitude readout stay in the normal operating range?

Hi, BradInteresting.... Are you starting all your PMDG flights on the ground? (Or have you saved a flight in the air?)Have you touched the MAN controls at any point during your ascent? (PMDG's NG doesn't seem to have the ability to recover after you manually alter the px controls, then return the switch to AUTO).Are your flights mostly from sea level or thereabouts?How long are your flights, usually?On your walkaround, did you notice any rubber door seals hanging out? :-)Cheers.Ian.P.S. The horn cancel button doesn't seem to be modelled, so I assume the pressurization warning isn't modelled.

Hi Ian,I start every flight from a cold and dark cockpit, on the ground. Departure elevation is typically around 1800ft MSL. Cruise altitude is anywhere from FL330 to FL370. My flights typically range from 1-3 hours.I always leave the outflow valve control to AUTO from start to finish. Weird problem huh? I'll look for bad seals :)Thanks for the reply!

"Weird problem huh?"Sorry, Bruce... I think I've just about run out of ideas. I sometimes come up with some strange cockpit indications if I have minimised the FS9 screen for a longish period of time (to work on something else on my computer), but I'm sure you wouldn't do this on every flight.If you were keen to experiment, perhaps you could try a few flights from a sea-level airport... then, if you really want to try to confuse the pressurization system, try a flight from SLLP (La Paz) to SLOR. Both airports are above 12,000'. SLOR has a few dirt strips, but I'm sure PMDG's NG can handle them ;-) But if you think getting into SLOR is a problem... try getting out (High altitude, short, bumpy runways and the airport is in a hole in the ground).Cheers.Ian.

Hi Ian,I'll try departing from Honolulu (appr. sea level) and then climb up to FL370 and see how it goes.