Implementation of STPA Methodology Into Military Jet Aircraft Certification Process According to EMAR Certification Criteria for Safety

Increasing requirements on reliability and safety of aircraft are emerging not only in civil aviation but also in the military aviation industry. In order to eliminate all possible safety risks, or to minimize them where they cannot be eliminated a lot of conventional methods are used, such as Failure Mode and Effects Analysis (FMEA), Failure Mode, Effects and Criticality Analysis (FMECA), Functional Hazard Assessment (FHA), Fault Tree Analysis (FTA) etc. Those are excellent system safety engineering methods widely used to ensure system operational integrity during the initial aircraft certification process. The European Military Airworthiness Requirements (EMAR) regulations explicitly mention the conventional methods as acceptable means of compliance for all safety related paragraphs. Nowadays, however, new approaches emerge that attempt to overcome some of the limitations of the conventional ones. One of the promising is the Systems Theoretic Accident Model and Process (STAMP) and the Systems-Theoretic Process Analysis (STPA) based on it. This method is based on qualitative analysis which, while very useful in the development phase of an aircraft, makes it difficult to directly connect the outputs of the analysis to the requirements of the military EMAR regulations, which explicitly call for some quantitative outputs. This paper presents a few cases where the STPA fits European Military Airworthiness Certification Criteria (EMACC), including how such qualitative method could be expanded to deliver some of the required quantitative outputs.

Keywords: Safety, Military, Aircraft, Functional Hazard assessment, Failure mode and effects analysis, Failure mode, Effects and criticality analysis, Systems theoretic accident model and process, Systems-theoretic process analysis, Aviation, European military airworthiness requirements certification.

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