I fix Boeings for the worlds most profitable Airline, for the most part the systems and logic behind the systems is the same across the current generation of Boeing products, the pressurization and passenger O2 can be turned off in the Flight Deck, the pressurization system has two primary but separate control systems which switch sides each flight, they are completely automatic, the pilot selects his final cruise FL and it does the rest, should both of those systems fail, the outflow valve can be controlled manually by either AC or DC power, the passenger O2 system is completely separate from the Flight Deck O2 system, the pilots have there own O2 bottle, O2 masks with built in microphones, in the passenger compartment each row of seats or bank of seats has a PSU(passenger service unit) the FA call button is there, gasper fan outlets and reading lights, as well as O2 masks for each person in a seat plus an additional for a baby or FA if need be, in the PSU is a O2 generator to supply forced O2 to each user, by pulling the mask when deployed out of the PSU pulls a pin, a plunger pierces the containers inside the O2 generator and the two chemicals mix and make O2, each Lav and the FA stations are all equipts the same as the PSUs, when the passenger O2 system in on, the deployment of the passenger masks is automatic, in the cockpit a cabin altitude warning horn will sound, telling the bus drivers to don there masks and get the plane down to a safe altitude. I would like to point out there is no access to the cockpit on modern airliners in flight from the passenger compartment, lets just say the door has been modified and leave it at that, and can only be opened from the inside, and since 9-11 crews know openning the door is certain death for them and everyone else. During a depressurization event with no forced O2 will deny each person the ability to open his/her diaphram to allow them to breath, accending to FL45(if that really happened) is not required to kill everyone. Transponders do not have an On\Off switch, but each has a circuit breaker in the cock house.
Here is my Therory, planes that do not operate in US Canada or European airspace are NOT maintained or operated at the same level as planes that are flown in our airspace, for instance a broken transponder is not dispatchable on a ETOPS flight, in Asia or Africa......................, a series of unfortinate events lead to this planes demise, the loss of the cabin(pressurization) caught the crew off gaurd, Oto flew the plane until the fuel tanks ran dry and the bird lawn darted into the water, if this was a hijacking there would only be hours to get back into the air and strike its target, every satilite we have has already searched every possible landing strip for this plane, only large airports will have a hangar big enough to hide a 777, all souls are on the bottom of the sea waiting for us to find them, the FDR\CVR pingers(if maintained) only have about 20 days left before they stop saying here I am come get me.
