Cabin Altitude Warning - [ 737 PMDG - Cabin Altitude and Rapid Depressurization ] 

Ladies and Gentleman Welcome aboard our flight today all about Cabin Altitude Warning on 737 PMDG. We are cruising at 32000ft, on our MSFS2020 ,its a nice clear day. Our flight plan is filed for a local flight over city of Mumbai.
Microsoft Flight Simulator
So to understand this we need to take a look at the pressurization panel.
We are going to keep this very simple and not dive much in to the details of the system
So lets take a look at the panel now. So here we have a AUTO, which is the normal mode.
If the Auto Fails the checklist will direct you to choose the Alternate Mode. Both these modes are automatic.
If both of the systems fail then its in the hands of the pilot to control the system, which is manual
So this system takes the Takeoff airport altitude, The pilot entered cruise altitude and the landing altitude. The controller manages a differential pressure between the airplane altitude and cabin altitude.
Throughout the flight the outflow valves on the airplane keep pressurizing and depressurizing the aeroplane, to make the cabin comfortable for the pilot and passengers
So now what i am going to do is, put the controller in manual mode, i am going to depressurize the aeroplane and show you how the cabin altitude rises. This is done by opening the outflow valve to open.
Do not do this in the aeroplane unless a checklist directs you to do it. What i am doing is just a demonstration to trigger the warning.
As the cabin altitude reaches 10000ft the warning triggers. This is the time when its required that the pilot takes immediate action. The actions are done by memory followed by a checklist.
Now if the pilot does not do anything and the cabin altitude reaches 14000ft the masks in the cabin will automatically deploy and help the passengers breathe till the time the pilots descends to a safe altitude.