Hi, I'm aware there are numerous variations of our manuals, maybe customized by Boeing for each airline (?)...
I noticed a very DANGEROUS mistake in ours, despite the Helios accident, Boeing still has it WRONG!
In the Normal procedures - I'm talking 737 classic but probably NG is the same -, where they tell you how to perform the mask test, I read:
If the oxygen cylinder is not in the full open position, pressure can:
.decrease rapidly. or
.decrease more than 100 psig, or
.increase slowly back to normal.
THIS IS WRONG!
Actually, the sensor is located BEFORE the crew shutoff valve, not after!
So, if the valve is closed, dumping the pressure with the EMERGENCY selector of the mask, will have absolutely no effect on the gauge reading.
Try it.
Close the valve. Dump the pressure using the mask.
Observe the reading of the bottle pressure.
You will se no movement.
This error is absolutely crazy, from the part of Boeing and airlines.
Or have I missed something?
