The oxygen regulator has three modes:
Normal: Red latch on left is up - Gives air/oxygen mix on demand. Use if no fumes are present eg decompression.
100%: Push red latch on left down - Gives 100& oxygen on demand. Use if smoke or fumes are present.
Emergency: Rotate red knob clockwise - Gives 100% oxygen under pressure. Used to clear mask & goggles of fumes and should also be used if aircraft is depressurised above 39,000ft.
Is there anybody here that knows why EMER mode should be used above 39000ft ???? How about 38000, 37000.........or 30000???
Last edited by DongJoon Choi; 10th Aug 2011 at 09:31.