Functional Hazard Assessment (FHA) is a reliability/safety design analysis technique [10
points]
a. Describe the objective of an FHA [5 points]
b. What are two characteristics of an FHA? [5 points]
a) Starting point for the generation and allocation of safety requirements
b) Using functions, flight phases, HAZOP words, classification according to AMC
Describe the Safety Assessment Process (SAP). Explain briefly which steps are involved
and the purpose of these steps [10 points]
- concept design and derived safety requirement
- reassessment and changes
- verification that design meets safety requirement
FHA, FTA, FMECA on A/C and system level
Iterative process which runs parallel with design process
FHA: functional failure modes. Using HAZOP as guidelines. Input for FTA
FTA: Single failures can be identified
FMECA: Latent failures can be identified
A Common Cause Analysis (CCA) is subdivided into three areas of study. Provide these
three areas and give a short explanation per area.
Zonal Safety Analysis
In those areas of the aeroplane where multiple systems and components are
installed in close proximity, it should be ensured that the zonal analysis would
identify any failure or malfunction which by itself is considered sustainable
but which could have more serious effects when adversely affecting other adjacent systems or
components
Particular Risk Analysis
Particular risks are defined as those events or influences, which are outside
the systems concerned. Examples are fire, leaking fluids, bird strike, tire burst, high intensity
radiated fields exposure, lightning, uncontained failure of high energy rotating machines, etc.
Common Mode Analysis
This analysis is performed to confirm the assumed independence of the events, which were
considered in combination for a given failure condition.
In the process of building an FTA, it’s important to consider the four FTA guidelines.
Provide two of the guidelines and explain them.
Failed system state wording
Be specific in your wording of (top) events. Use identical wording only for events when it
reflects exactly the same failure mode (necessary for a correct FTA evaluation).
The inclusive rule
Determine a strategy with which you can include all possible contributory failure modes.
The progressive rule
points]
a. Describe the objective of an FHA [5 points]
b. What are two characteristics of an FHA? [5 points]
a) Starting point for the generation and allocation of safety requirements
b) Using functions, flight phases, HAZOP words, classification according to AMC
Describe the Safety Assessment Process (SAP). Explain briefly which steps are involved
and the purpose of these steps [10 points]
- concept design and derived safety requirement
- reassessment and changes
- verification that design meets safety requirement
FHA, FTA, FMECA on A/C and system level
Iterative process which runs parallel with design process
FHA: functional failure modes. Using HAZOP as guidelines. Input for FTA
FTA: Single failures can be identified
FMECA: Latent failures can be identified
A Common Cause Analysis (CCA) is subdivided into three areas of study. Provide these
three areas and give a short explanation per area.
Zonal Safety Analysis
In those areas of the aeroplane where multiple systems and components are
installed in close proximity, it should be ensured that the zonal analysis would
identify any failure or malfunction which by itself is considered sustainable
but which could have more serious effects when adversely affecting other adjacent systems or
components
Particular Risk Analysis
Particular risks are defined as those events or influences, which are outside
the systems concerned. Examples are fire, leaking fluids, bird strike, tire burst, high intensity
radiated fields exposure, lightning, uncontained failure of high energy rotating machines, etc.
Common Mode Analysis
This analysis is performed to confirm the assumed independence of the events, which were
considered in combination for a given failure condition.
In the process of building an FTA, it’s important to consider the four FTA guidelines.
Provide two of the guidelines and explain them.
Failed system state wording
Be specific in your wording of (top) events. Use identical wording only for events when it
reflects exactly the same failure mode (necessary for a correct FTA evaluation).
The inclusive rule
Determine a strategy with which you can include all possible contributory failure modes.
The progressive rule
