In terms of altitude (6000, 7000, 8000, etc), what is the cabin pressure in a CRJ-900?
1$\begingroup$ I could be completely mistaken, but isn't that usually set by the pilot? You might want to compare e.g. How does an airliner deal with cabin altitude at an airport above 8000 ft? $\endgroup$– userOct 5, 2018 at 14:03
$\begingroup$ The answer to this question (as asked) will depend on two factors: how the pressurization system is operated, and at what pressure altitude the aircraft is. In its current state the question is unanswerable. I think the question might be better asked along the lines of: "what is the cabin altitude at maximum differential pressure and FLXYZ". $\endgroup$– J WOct 5, 2018 at 14:13
At max differential it's 8000 ft. The controller operates on an automatic program schedule that lets the cabin pre-pressurize to about 300 ft below field elevation at the start of the takeoff to minimize the initial pressure drop sensation following liftoff. It then lets the cabin altitude rise 500-800 fpm, about 1/4 of the airplane's actual climb rate, until it gets to the max differential of just over 8 psi, which gives 8000 ft in the cabin at 41000 ft.