"Tim Shoppa" wrote in message
oups.com...
| the other must go on oxygen
|
| What are the European rules on oxygen generators?
|
| In the US the passenger oxygen generators are chemical based, and
| unfortunately not really testable until you need them.
|
| In the US, the crew oxygen is from pressurized oxygen cylinders.

I need to clarify this. I only build widebody Boeing aircraft, so I'll
throw this out as fact as it relates to widebodies: 747's can be bottles or
generators, whatever the customer orders. 767's are only generators. 777's
are either as well. The crew in the flight deck has bottles mounted nearby.
Flight attendants have bottles mounted throughout the airplane that are
removable and can be carried around, or if needed, provided to passengers.
Some planes are equipped with medical oxygen outlets for when they need to
replace a seat with a stretcher and provide the passenger with oxygen on a
continuous basis throughout the flight, so can be partially pumbed. The
governing aviation authority has no specifications about the source of
oxygen. There are advantages and disadvantages to both. The Passenger
Service Units (PSU's) are a complete module that are easily reconfigured
with the airplane, but plumbed oxygen requires more hassle, obviously. Some
folks don't like the plumbing all over the plane with pressurized oxygen,
but it is lighter than all the generators, which are a bit hefty.
Chemical generators have a shelf lift. Remember that plane that augered
itself into a Florida swamp? It was carrying out of date generators on
pallets in violation of FAA regulations. When one goes off, they all get
set off by the heat.

| One could imagine a low-budget airline not keeping good tabs on the
| crew emergency oxygen cylinder or the plumbing. (I can imagine looking
| at the cylinder gauge every flight but never checking that the plumbing
| is intact...)

The 737 line has put gobs and gobs of planes in the sky. There's so
many of them that any accidents will show a preponderance of damage to them.
The airlines that maintain them are often shabby excuses for a business that
I wouldn't trust them to run a taxi fleet, but the 737 is such a well built
and designed airplane that it keeps an awesome safety record despite the
best efforts of idiots/

| Worst case is that the passenger oxygen systems work fine but the crew
| is locked up front with no oxygen. "I'd rather die peacefully in sleep
| like my grandfather, not screaming in terror like his passengers".
|
| Tim.

There is a system on board that when cabin pressure drops below a
certain point the PSU's all open up and the masks fall down. The fact that
they were all down meant that the system worked as meant to. If there were
a leak in the cabin air conditioning system, oxygen deficient air can be
circulated in the cabin, and unknowingly, especially if most are asleep,
they will either pass out or die gently. Some stayed awake because there's
always a few odd ones out there. The crew gets the same ambient air as the
cabin. They are no different in that respect. With the plane on autopilot,
the crew up front has little to do other than read a paper or book, take a
nap (one at a time, supposedly,) or snuggle with a stewardess (or steward,
for those inclined or so equipped!) so I can see both pilots dozing off as
well. Eventually the system keeps cooling down and they will all freeze.
Autopsies will further determine what happened, as to the oxygen levels in
the blood of the passengers and other stuff.