I was truely amazed by this. It just shows how in depth this simulation really is.When on the ground, close all doors, except one. Open the cabin press controller, and set it to manual and close the valve. Set SD to AIR and monitor the ----CABIN---- info on the right. Now close the door and see how the plane starts to pressurize. Note a rato of about -1000 fpm. Now open the door. Not only does it depressurize (of course) but the rate indicates the "sudden" drop. Rates in access of 2000-3000 fpm turn the legend into a boxed amber before slowly tapering of and leveling back to 0.Amazing.....just try to fathom how many man hours had to go into this piece of simulation alone and you'll get the idea of how much work must have been involved.Cheers,Xander

Xander,thanks for appreciating all these details, you've just made Michael's day! :)He spent an endless amount of hours to get all this detail into the software!Markus

Markus, To be fair, it is true that I have spent endless hours for several details on the MD-11, but this particular one belongs to Dr. E. Vaos who has also gone through the same detail hunting process.

Forget that, a big cheers to ALL of you. Not for giving this to us, but for loving what you do so much to actually want to delve so deep into something you will NEVER notice for the life of your MD-11 probably.Xander

Not to mention the difficulty in opening that door :)Got to vent the pressure before opening doors- which is why the outflow valves typically end up full open on the ground.

Indeed! Something weird happened though - I lost all three engines yesterday, the packs turned off as they should, the outflow valve closed - and during my descent I managed to build up negative differential pressure with the cabin at 8000ft and the aircraft at 3000 - there should be a negative delta p relief valve, since the fuselage is not designed to take compressive radial stress... Any ideas?Cheers,Niklas

>8000ft and the aircraft at 3000 - there should be a negative>delta p relief valveThe systems manual says the the negative pressure relief is provided through the door seals.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

Didn't read that part - hmm, interesting. Whats peculiar is that the cabin pressure remained constant though, no change at all... I'm aware that the 737 series has an inboard opening door, working pretty much like a letterbox specifically for that purpose.