The FHA is a function by function analysis that establishes the severity of the failure conditions of each aircraft or system level function, e.g. loss of braking, uncommanded braking, opening a specific valve, etc.
Aircraft FHAs are performed at a high level and used to identify the aircraft level safety requirements, e.g. FC and severity (CAT, HAZ, MAJ, etc).
System FHAs are more detailed and identify system failures (single and combinations) that contribute to the aircraft level FCs.
Both FHAs are qualitative and provide the top events for the PSSA’s FTAs …
