Originally Posted by
Justapax1
Safety lifejackets have never been known to save a life, but have cost a few, The Ethiopian Airways sea-landing after a hijack, when people inflated their lifejackets before exiting the cabin, and drowned.
Have oxygen masks ever saved a life? They only have a capacity of 2l, whereas I carry a 22l cylinder for a long-haul flight. Is 2l enough for the pilots to get the aircraft down below 5000 ft where there is enough oxygen that the atmosphere is breathable? From 45,000 feet?
Would it be too much to ask to have airlines provide oxygen on demand at the press of a button? I'm sure it wouldn't cost much more than having coloured lighting on demand on B777s and the ability to adjust the temperature of your seat's environment, also on 777s
I'm not sure where you are getting the 2L from? On the Boeing 777 for example the crew have a large oxygen cylinder with over 3000L capacity [some Boeing 777 have two crew cylinders] that are below the floor that supplies them in an emergency, while the 16 full size oxygen cylinders [again all over 3000L] are located in the rear freight bay....I know I've had to change many in my engineering career.
The bottles are pressurised to approx 1850 psi and are on a ring-main that supplies the oxygen in an emergency situation. On the Boeing 747 [which also had a ring main system] there was also a connection in the overhead PSU for therapeutic oxygen, in that a mask could be plugged in and the pilot could switch on therapeutic [low pressure] oxygen supply for a passenger if required.
These oxygen cylinders have to be able to provide both the crew and a full compliment of passenger with oxygen for a set period of time [from memory it might be 45 minutes but, that I'm not absolutely sure about it was many years ago when I sat licences] So yes, to answer your question the emergency oxygen system can supply both crew and passengers for more than enough time.
I think you are getting confused with the with the small portable oxygen cylinders that are located at the door stations which are small bottles that can be used by the cabin crew in emergency situations
With regard as to why airlines do not offer therapeutic oxygen ay more, is that a lot of modern aircraft no longer have either the outlets in the PSUs or a 'ring main system' A lot of modern airliners, now rather than the many full size oxygen cylinders in the freight bays and all the associated plumbing around the aircraft actually have gas generator bottles on the overhead PSUs where the oxygen is 'produced' in an overhead bottle in an emergency situation. Again, the amount of time oxygen is available for is governed by law, so has to meet all the required standards.