Flight 9252: Wait a minute, when they open the cargo door, isnot the passenger cabin depressurized?

german wings accident met aanwijzenGood question! From what I can find on the internet, the answer is “no!”. [Any aviation experts out there, please fill in the blancs] First of all, the altitude where this happens is about 2200 metres. Also, from what the media tells us, according to the black box, there was no loss of pressure before the crash. When cabin pressure becomes an issue, oxygen masks are provided (would happen automatically). None of that happened. Does this also mean the below deck cargo door could not have been opened?

With all I have so far of the Germanwings crash of flight 9252 on March 24 2015, I am convinced the official story is not true. There is no reason to think Andreas Lubitz committed suicide taking 149 lives with him. Instead, very likely pilot Sonderheimer committed the act and framed Lubitz. Read a summary of my analysis here: link.

It is possible to open the below deck cabin door, without heavily disturbing the passenger deck cabin pressure.  How does it work? The passenger cabin of an airplane is pressurized in the air (and airconditioned/heated), because else no passenger would be comfortable, warm nor could they breath without an oxygen mask. The two cargo decks (front/back) in the A320 are pressurized to a similar pressure, which is necessary because elsewise the floor of the passenger deck collapses, due to the pressure difference. The cargo bays in all transport rated aircraft are pressurized, but they aren’t allways heated. The front cargo area can be heated (that is where they would keep live animals during flights etc.). So the cargo area and the passenger deck are seperate compartments, yet both pressurized to a similar pressure.

What would happen due to the cabin pressure in the front cargo deck, when one would (a) open the cargo door and leave with an (high temperature) rocketering ejection cabin? The cabin immediately decompressurizes. There are pressure relief valves between the cargo deck and passenger deck, in case something goes wrong. This means that when pressure differences between below and passenger deck becomes to large so the floor would collapse, some air is released between the two decks. It will influence the pressure in the upperdeck, yet slowly. In our case, something else is happening immediately after the opening of the cargo door: the rocketering mechanism.

What will be the impact of a rocketering mechanism on below deck compartment pressure? (b) The air below deck will be heated, which increases pressure even though (at the same time) the pressured air in the compartment is leaking outside. (c) The rocketering mechanism will likely heat the bottom of the fuselage shortly, which will soften the structure. The problem with this is, all three changes impact the pressure in the front compartment below deck: (a) the door opening, (b) the temperature increase, (c) the possible melting of the bottom fuselage (Gas Law physics pV=nRT). Even for an expert this would be a challenge to analyze. In any way, it will take some seconds before the leaking of pressure in the below deck, will seriously impact the passenger deck air pressure (through the pressure valves).

All this isn’t a problem. Why? Because it occurs (link) at about 2200m height, an altitude where the pressure difference between cabin air and outside air is limited.

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