The Nimrod Review - Official Documents

Serial
Recommendations Status
Number
3 The Nimrod Safety Case (SC) is reviewed, reassessing the Action Continuing.
factual data used for interpretation and categorization
Review commenced by BAES on 3 Dec 07 and initial target completion date was Apr 08. However,
of hazard and risk. The review should include widespread
as work progressed it became clear that the review would require more extensive effort than
operator (air and ground crew) involvement. This work
initially planned. The changing strategy imposed additional work and concomitant delays in
should be incorporated within the review of Nimrod
completion dates. BAES estimated that they would be unable to complete the SC until 2010.
maintenance policy.
Although the SC review is not yet complete the Nimrod MR2 Safety Engineer, supported by the
PSEWG, is confident that the wide-ranging, complementary, independent studies, and the XV
236 tear-down, have provided enough information for him to confirm that the Nimrod remains
safe to operate. In addition no evidence has been produced from the ongoing work on the SC
that would call into question Nimrod airworthiness.
Nonetheless, in view of the delays in the provision of the SC, the Nimrod Team has developed
an alternative means of completion. The Nimrod Team has been working with QinetiQ to
produce a SC (based on a model successfully completed for the BBMF), whilst still using BAES
information where available. The Nimrod Team approach was endorsed during the D AS Nimrod
2* Airworthiness Review held on 21 Jul 09.
The Nimrod PT Project Engineer reported to an Extraordinary meeting of the PSEWG on 2 Oct 09
that he intended to recommend to the RTSA that the Nimrod Equipment Safety Case (ESC) be
accepted.
The ESC will now be independently reviewed. This review will comprise 2 elements. The Independent
Safety Audit (auditing the structure, method and logic of the safety case) will take approximately
6 week. However, an Independent Technical Evaluation of BAES’s zonal and functional hazard
analysis (which is a major contributor to the equipment safety case) will be conducted in parallel
and is estimated to require 8 – 12 weeks. While these tasks are underway the Nimrod PSEWG
agrees that work already completed will continue to support the safe operation of the Nimrod.
Appendix A to Chapter 15
Final confirmation of the integrity, accuracy and applicability of the ESC will be provided by
this process and, thus, this action will remain open until both independent checks have been
completed.
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