Doesn’t really matter where the O2 comes from, the process has a off switch, I can guarantee it, in modern planes. The oxygen generators you speak of, they actually used a non-reversible process manually triggered.
Why are you so combative? The end result is that pure oxygen is released into the atmosphere. This is a fire risk.
Also, thanks for the suggestion on the Google search. The 777 uses oxygen bottles, not generators. Probably should take your own advice before attempting to smack someone down in the forums :)
http://www.smartcockpit.com/download.php?path=docs/&file=B777-Airplane_General_and_Emergency_Equipment.pdf
http://www.theairlinepilots.com/forumarchive/b777/b777references.pdf
http://en.wikipedia.org/wiki/Chemical_oxygen_generator
Smackdown. Sorry, but when some doubts or makes comments that are blatantly not correct without first looking up the facts, specially about something i do and am fluent in, it does drive me a little crazy.
Technical name is: Chemical Oxygen Generators. Its a chemical when ignited creates oxygen. I am sure maintenance engineers might know of a way, but the only switch for these masks is to DROP them. There is no switch to prevent them from dropping. They automatically drop when the cabin altitude reaches a certain point. Usually 14,000 feet. Is a pressurized mechanism that controls them
I am not guessing, i am not giving an opinion. I am trying to tell you. I have been flying commercially for 30 years. I am trying to tell you something. You refuse to believe or listen. Look up smartcockpit.com general and emergency equipment will tell you all about it.
Look up Chemical Oxygen Generators at wikipedia it will explain how they work.