Functional Breakdown and FHA

Question 1

Safety Assessment Process

V-Model

Answer 1

The safety assessments follow the same process as the system development:
- top down development followed by bottom up verification
Picture T3 F3

Question 2

Functional Hazard Assessment

Answer 2

Top down analysis usually done in the beginning: The aim is to evaluate plausible top-level failure conditions without taking into account the architecture. The FHA forms the top-level safety requirements to be used in the following more detailed analysis

Question 3

FHA focuses on…

Answer 3

Only functional failures rather than system or component failures should be elaborated.

Question 4

2 hierachy levels of development with FHA

Answer 4

In the Aircraft FHA we investigate the top level aircraft functions (e.g. control rotor thrust, provide lift, etc.) and their corresponding failure conditions while in the System FHA the focus is on the failure conditions of an aircraft’s subsystem (e.g. Collective pitch control system, Hydraulic System, Thrust Reverser, etc..)

Question 5

Typical failure conditions (FHA)

Answer 5

• Loss of control
• Partial loss of
• out of control
• inadvertent