Compliance verification method on CCAR 25.1443(c) for civil aircraft passenger oxygen system based on blood oxygen saturation

Abstract

This paper generally introduces the compliance verification method on airworthiness regulation CCAR 25.1443(c) of popular passenger oxygen system on civil aircraft firstly, then technical interpretation on regulation CCAR 25.1443(c) <Minimum Mass Flow of Supplemental Oxygen> is demonstrated and method of satisfying this regulation in Top-Down design is analyzed. For those passenger oxygen system based on blood oxygen saturation which is not directly fulfill the requirement of the regulation, equivalent altitude theory is established to transform mean tracheal oxygen partial pressure required by the regulation to blood oxygen saturation index of equivalent altitude, and user’s blood oxygen saturation of these passenger oxygen system is equivalent or higher than that transformed from the regulation through actual human body physiological test and theoretical analysis from aviation physiology, then compliance to the airworthiness regulation is demonstrated by Equivalent Level of Safety. This paper gives the compliance verification method on the airworthiness regulation for those passenger oxygen system based on blood oxygen saturation on civil aircraft and this method have been used and gotten approval of the Authority for a type of civil aircraft. This paper also provides theoretical basis and test basis for further airworthiness regulation revising of the regulation CCAR25.1443(c).