Overview
After deriving the functional hazards during FHA, further safety analyses is required to identify physical hazards of the system and the common cause failures associated with the design. As such, a system level ZHA of the refuelling pods is required to understand the associated physical hazards and common cause failures of the equipment and feed them into the safety assessment.
Workshop Objective
The objective of the workshop is to consider the components of the refuelling pod and to identify hazards and the associated effects on the aircraft while considering both loss of detection methods and state of aircraft post detection.
- Select a ZHA leader and Recorder. The leader will facilitate the ZHA workshop under the guidance of the Tutor. The Recorder will populate the ZHA worksheets.
- Carry out a ZHA study for the refuelling pod.
- Guidance.
The first task within ZHA, which is independent of the zone itself, would be the preparation of design and installation guidelines for each new system and the components within the system. A generic example has been provided in Appendix A. The next task would be to inspect each zone of the refuelling pod against these guidelines for conformity to the guideline recommendations. Assume that this has already been completed by the Design Organisation.
For this workshop:
- Identify the failure modes of the systems/items, the external failure effect, and the resulting effect on the aircraft should be considered by analysis. The effect of these failure modes on the adjacent systems should be judged based on the system description.
- Consider the checklist for interaction of Systems (Appendix C) for all components within Zone 1 and identify effects on system, aircraft and if time permits, how the failures may be detected by the aircrew.