Question for Bus guys, when we check the crew oxy bottle pressure during the cockpit prep checklist, if the engineers had turned the oxy bottle off, would we still see pressure being indicated? Ie is the pressure sensor in the line or the bottle?
If we turn the overhead crew oxy rocker switch to off, that oxy indication goes Red or Amber by memory (different from the half boxed Amber presentation we often see). If oxy bottle was turned off but there was residual pressure in the line, we might still be able to carry out a positive oxy mask test and think all is well and if the sensor is in the bottle, the indicated pressure will also look good. Hopefully Air Bus have a safety feature to prevent this situation.