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Sabretooth78

Cabin Pressure

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I experienced the problem on a A321 flight today with version 1.2.3.1. Never seen it before, P Delta went up to 10.3 and cabin altitude was 200 feet.  

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I just had it on my latest attempted flight (which I ended up aborting) running 1.2.3.1.  The Cabin Altitude was stuck at -150.  Unfortunately the log files got overwritten as I fooled around (see below) with it afterwards, if in fact they would have been any help.

 

After exiting P3D, I immediately went back in and loaded the last autosave.  The issue was still present, only this time the Cabin Altitude would start at -150 and almost immediately change to -200.  I reloaded a few more times and this happened every time.  I then reset the scenario to put me back on the ground, wondering if I could see something telltale hoping if it happens in the future, I can see it before it happens and reload or whatever.  P3D then reloaded me back on the ground, but crashing along at 300 knots instead of stopped.  Interestingly, the problem was now gone, and the Cabin Altitude changed apparently normally as I climbed off the ground for some distance!

 

Restarting P3D again and returning to the autosave, the same exact behavior persisted.  I figured I'd throw the kitchen sink at it and see what stuck.  A scenery refresh did nothing, nor did actually reloading the aircraft from the menu.

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Howdy, first, the Airbus Pro series is outstanding! But (there's always a but!), I have no cabin pressurization occurring at all. I am flying the A320 Pro (version 1230) in P3D V4.4. I always fly between KORD and KCLE at FL310. The ECAM display for pressure shows the outflow valve always closed, and by FL310 the delta P is over 9 and the cabin alt stays at 500 ft the whole flight. This happens consistently for every flight. Let me know if you need data from me, tell me how to turn on the logging, etc. I don't have screen shots right now, but I just did look at the status just after doing the cockpit prep checklist and after push back and engine start and ready for taxi, and the display is correct, the outflow valve is wide open, delta P is at zero, and cabin alt is at 700 ft (Elevation at KORD is 650 ft). So, initially, it appears the pressurization starts out as if it is functioning correctly (I'm thinking at some point the outflow valve must be slapping completely shut after take off to get this type of failure, not sure when though). I fly from a saved flight at a KORD gate in a dark and cold initial condition.

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Hello bworld1, to enable logging please see this thread
 

 

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Thanks for getting back! I just got done with a test flight. This time I set up on the active runway, no saved flight, with the aircraft state at "Take off state". I took images, but I don't think you need to see those, since the Pressurization worked completely fine. By FL310, the cabin pressure had slowly risen to 6150, which is correct, and delta P was about 8. So, in my case, the issue must be either with the Cold and Dark state not turning the Pressurization "On" correctly (those knobs on the overhead are non functional and have no lights on them, but no lights means "ON" anyway, but the point is that I don't have control of those), or my problem is with the saved flight. I will troubleshoot this and make a log of the failing situation. By the way, the one thing that has sort of bothered me even with the older A32x series planes is that as I leave the ground the display shows the outflow valve dropping smoothly but quickly to completely off. I thought that this valve should be displayed as varying depending on what cabin pressure the system is trying to achieve, in other words the outflow valve is the regulator, and shouldn't really be closing all the way, it should be adjusting itself based on cabin alt  pressure that is desired at any particular time. This is what I saw when flying a 777 and what I thought I read on the internet.

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OK, I am posting logs of the cabin pressure failure. I flew the A320 United model. I set up an unsaved flight using the Cold and Dark state. I included 4 screenshots. First is on the ground and shows cabin alt of 700, then once in the air the next shots show cabin alt stuck at 500 up through FL100. When I was supposed to transition from 11,000 to 17000, I accidentally hit my throttle off (I never do that, it figures I would do that when getting logs!) had to get it back to climb detent and turn the auto-throttle back on and get the speed back under control. So, I decided to stop the flight after that blunder, but the cabin alt should have been at least 2000 feet at FL100. I hope this helps, let me know if you need me to do something more/right.

pressureFailure.zip

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Thanks for the great and prompt response! Here are 2 more screenshots, one at fl310 (delta p is 10.2), and one after landing at KCLE and pulling off runway. The Cabin alt is correct for KCLE. I made logs, in case you need them. Also, I have visited 6 or more sites about cabin pressurization in real planes, a few specifically about the A320. In all cases, the outflow valve is constantly being controlled/modulated by the computer systems (assuming not in manual mode) to maintain a given pressure in the cabin. I don't see that being represented on the ECAM pressure display even when it is working correctly. Also, the cabin alt display should go red in the A320 when/if the cabin alt goes above 9550 ft (indicating a failure). And the Delta P did go yellow above 8 in the failed flight. It should change indicate a serious situation if it goes above 9 (indicating a failure), not sure if it should change to red.

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