Particular Risk Analysis
PRASection 06: System Safety & Functional Safety
Definition
A safety analysis that evaluates the effects of specific external hazards (particular risks) on the aircraft systems, to ensure that these hazards cannot defeat the safety architecture through common cause effects. Particular risks include uncontained engine rotor failure, bird strike, tire burst, wheel rim release, fire, lightning, high-intensity radiated fields (HIRF), fluid leakage, hail, and other external threats. For each particular risk, the analysis identifies which systems and components could be affected, evaluates whether the system architecture provides adequate protection (through segregation, shielding, or separation), and determines the resulting failure conditions.
Where This Shows Up
Particular risk analysis addresses external threats that can physically damage multiple systems simultaneously. For example, an uncontained engine rotor burst can send high-energy debris along defined trajectories, and PRA evaluates which systems lie within those threat zones. The analysis results may drive design changes such as physical separation of redundant systems, shielding, or re-routing of wiring and fluid lines.
Primary Sources
Defines PRA methodology as part of Common Cause Analysis.
Regulation requiring evaluation of engine rotor burst effects, a key particular risk.
Related Terms
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