Stupid question about in-cabin fires
- Thread starter BCTAv8r
- Start date
Cptnchia
Dissatisfied Customer
No. The concentration of O2 in the atmosphere, 21%, doesn't change as you go up, only partial pressure. There is the same amount of oxygen, just fewer molecules per cubic area. Fire will still burn. Plus, if you dump the cabin, then the oxygen masks will deploy and now you are pumping pure O2 under pressure into an area with fire present. It's the same as throwing gasoline onto the fire.
jynxyjoe
Queso King
Heh.
Just to be clear, the cockpit crew WILL use oxygen, but absolutely do not feed the rear oxygen.
On the airplane I'm currently on, there are like 3 different bold print warnings not to let the cabin exceed 13,500 ft because the masks will deploy.
However.
We are allowed to manually depressurize the cabin slowly so to pull smoke out of the cockpit. Basically, PRESS CONTROL... MAN MAN ALT... UP MAN RATE... INCREASE AS REQUIRED, HOLD, WHEN SMOKE HAS CLEARED.
You'll have to do it a few times.
At no time does it indicate, nor would a do, a big old pressure dump.
Just to be clear, the cockpit crew WILL use oxygen, but absolutely do not feed the rear oxygen.
On the airplane I'm currently on, there are like 3 different bold print warnings not to let the cabin exceed 13,500 ft because the masks will deploy.
However.
We are allowed to manually depressurize the cabin slowly so to pull smoke out of the cockpit. Basically, PRESS CONTROL... MAN MAN ALT... UP MAN RATE... INCREASE AS REQUIRED, HOLD, WHEN SMOKE HAS CLEARED.
You'll have to do it a few times.
At no time does it indicate, nor would a do, a big old pressure dump.
EatSleepFly
Well-Known Member
Guess it depends on the airplane. Not a stupid question at all...
On the Lear 31a, deploying pax oxygen is one of the immediate action items on the "cabin/cockpit fire, smoke, or fumes" checklist, but it doesn't call for depressurizing fully, just manually up to a 13,000 ft. cabin altitude.
On the Lear 60, initiating an emergency depressurization is one of the five immediate action items for a cabin fire, which will of course cause the pax oxygen masks to deploy.
On the Lear 31a, deploying pax oxygen is one of the immediate action items on the "cabin/cockpit fire, smoke, or fumes" checklist, but it doesn't call for depressurizing fully, just manually up to a 13,000 ft. cabin altitude.
On the Lear 60, initiating an emergency depressurization is one of the five immediate action items for a cabin fire, which will of course cause the pax oxygen masks to deploy.
I'd put the switch in "crew only" if I were worried about the pax oxygen mask feeding the fire. I'd be much more interested in getting the smoke/fumes out of the cabin, so yeah I'd dump the cabin (it stops at 14,500' +/- 500') while wearing my mask and get the emergency descent going. Our cabin dump works REALLY well, it turns out (not sharing how I found that one out the hard way...whoops) so there ya go.
-mini
-mini
Crockrocket94
Well-Known Member
Like previously stated, generally only to get the bad air out.
It has nothing to do with the fire, but removing smoke if its bad.
Bad air out, good air in.
Generally dumping the cabin is a last resort, but bringing the cabin altitude up and increasing the rate is generally the first smoke removal tool.
It has nothing to do with the fire, but removing smoke if its bad.
Bad air out, good air in.
Generally dumping the cabin is a last resort, but bringing the cabin altitude up and increasing the rate is generally the first smoke removal tool.