Page:Report of the Board of Inquiry into the Helderberg air disaster.djvu/269

 84 APPENDIX "I"

QXYGEN SUPPLY SELECTIONS
Tha cockpit crew oxygen regulators had 3 different supply selections available, viz: (1) NORMAL (2) 100% (3) EMERGENCY

NORMAL; This selection supplied a mixture of cabin alr and oxygen on demand; the ratlo being dependant on the cabin height. At a cabin height of 14000 leet, the ratlo was approximately 1:1.

100%; This was the usual selection for all lllghts and supplied 100% oxygen on demand.

EMERGENCY; This selection delivered a pressurised supply of 100% oxygen at a constant flow. This selection would have prevented the ingress ol toxic gases into the mask.