Definition of failure conditions for functional hazard assessment of civil aircraft cabin pressure control system

In this paper, 10 functional failure conditions applicable to civil aircraft CPCS are summarized, and the definitions of the levels of these failure conditions are explained. The effects of pressure release at different altitudes are evaluated in detail, especially the failure condition of depressurization of cabin (cabin pressure altitude is more than 25000 ft and lasting 2 minutes) is evaluated using the DEI method, which can be used as a reference for other civil aircraft CPCS to do equivalent safety analysis. At the same time, it can be used as an input reference for the detailed preliminary system safety analysis (PSSA) and preliminary design of CPCS.