2007-12-16 10:33:37 · 8 answers · asked by Anonymous in Cars & Transportation ➔ Aircraft
Are you asking about the indicated pressure in the oxygen bottles or the flow rate to the mask? On what aircraft?
There's a normal/100% selector on the mask that will provide normal air/oxygen mixture on demandand is dependant on cabin pressure. Pushing the 100% selector gives the pilot 100% o2 on demand.
747-400's have separate crew and passenger oxygen systems. The crew has 2 bottles, the passenger have 10, more or less depending on the airline.
The crew test the oxy masks before every flight and maintenance test them before the crew gets there. Some airlines require at least one person wear the mask when there's only two pilots in the cockpit. Some airlines have an oxygen outlet near the reading lights where a passenger can plug in and use a oxygen mask .
Since both passenger and crew systems are being used independently, sometimes the crew is higher, sometimes not.
Here's a picture of the EICAS on a 747. OXY PR: crew 1790 psi passenger 1970psi. http://i198.photobucket.com/albums/aa130/747400erMate/12-17-07_1257.jpg
2007-12-16 16:41:42 · answer #1 · answered by stolsai 5 · 1⤊ 1⤋
Pilots have 'on demand' oxygen available in the flight deck at all times. Passenger oxygen systems will only activate if pressurization falls below a certain level or if manually deployed by the pilots. The passenger system will only last for about 15 minutes and will be enough to keep them conscious. I would imagine the pilots have a better quality system as they need to be alert for flight control.
2007-12-18 07:49:39 · answer #2 · answered by 13th Floor 6 · 2⤊ 0⤋
Actually it doesn't. In fact, the passenger oxygen system in many aircraft does not have any "pressure" at all. It consists of chemical canisters that , when activated create breathable oxygen for emergency situations. For the pressurized systems the actual pressure is the same, the volume is what varies. As the demand would be a lot bigger for the passenger area, it has more bottles than the crew system.
2007-12-16 22:27:26 · answer #3 · answered by Otto 7 · 1⤊ 3⤋
On all Douglas, Airbus, Boeing and the Lockheed L-1011's there is no passenger oxygen system.
There are chemical oxygen generators installed in each overhead unit. They are the same ones that caught fire while being transported in the Value Jet aircraft that crashed in Florida.
So, as the others have said, there is no pressurized O2 system in large transport category aircraft. There may be a system installed in smaller aircraft.
2007-12-17 19:45:58 · answer #4 · answered by RGTIII 5 · 0⤊ 2⤋
On the DC-10(the only airliner I know because I crewed it)the o2 presssurized system is only for flight crew. It consists of three bottles in the FWD Under Floor Access. One for each member, PIC, SIC, and FE. The passengers rely on O2 generators and thats all.
2007-12-17 07:12:35 · answer #5 · answered by Anonymous · 2⤊ 0⤋
patrick is wrong! most systems use 1850 psi o2 pressure. the system is the same for pilots and passengers. there is a switch called 12500ft switch. when the cabin pressure depressurizes above 12500, the pilots can reserve O2 at 100% passangers will recieve amisture or none. this allowas pilots to decend and control the aircraft.passangers will just fall asleep.
2007-12-17 06:22:59 · answer #6 · answered by america first 5 · 2⤊ 2⤋
You just need to keep the passengers alive. But the flight crew needs to be alert too.
2007-12-17 06:42:01 · answer #7 · answered by rohak1212 7 · 1⤊ 2⤋
To ensure that the crew has enough oxygen and keeps them conscious and out of a hypoxic state.
2007-12-17 00:35:28 · answer #8 · answered by Jacob D 2 · 1⤊ 3⤋