The Nimrod Review - Official Documents

Chapter 5 – Leak from Fuel Coupling
starboard defuel valve was found to be leaking (categorised as a ‘Seep’). On investigation, the seal of a nearby
Avimo coupling, (possibly dismantled to allow the FRS coupling to be changed) although not leaking, “was
found to be badly deformed and distorted, suggesting that the seal has been fitted for some considerable time
...”. In my view, an equally likely explanation is that this was, in fact, one of the seals manufactured by Cellular
after 2000 from the new, non-conforming material.
Who is responsible for the fact that non-conforming Avimo seals were fitted to the Nimrod?
5.117
5.118
5.119
5.120
Cellular
5.121
A number of questions arise in view of the matters set out above as to the roles and responsibilities of: (a) those
manufacturing and/or selling Avimo seals at the time; and (b) those organisations within the MOD responsible
for their procurement.
94 DE&S Safety & Engineering carried out an audit of the supply chain for the NPPO Contract following the
discovery of the non-conforming Avimo seals. The conclusion it reached was that adequate supplier certification
and contractual conditions existed for the delivery of the Avimo seals, but only if the processes and controls
within those certifications and specific conditions were implemented. The audit concluded that there were four
root causes of the provision, delivery and acceptance of the non-confirming seals:
5.117.1 The Design Authority/Rights Holder (i.e. Avimo/Thales) did not carry out a review of a very old drawing
with a view to its validity and potential obsolescence issues, but continued to place Purchase Orders.
5.117.2 The manufacturer of the items (i.e. Cellular) did not declare its inability to produce the items to the
contractual drawing in line with the contractual QA requirements placed upon it.
5.117.3 There was a lack of effective, if any, QA review of Cellular.
5.117.4 Contractor A and Contractor B operated at the ‘Part Number’ level and essentially relied on third
party certification and Certificates of Conformity in satisfying themselves that a product met customer
requirements. Typically, no product related enquiries were made, e.g. as to obsolescence.
The audit went on to recommend that the structure of contracts which involve spares of any, but in particular
old, designs should have obsolescence management considerations defined.
I discuss below the extent to which I agree with these conclusions, and where I consider the ultimate responsibility
for the provision of the non-conforming seals lies.
I consider first of all the position of Cellular, in respect of whom it seems to me three questions arise.
5.122 First, should Cellular have appreciated that the original order (and subsequent orders) from Avimo/Thales were
for aviation use? In my view, no. Cellular was a general rubber manufacturing company and not a specialist
aviation supplier. There was nothing in the Avimo Drawing to suggest that the order was for fuel couplings, let
alone aviation fuel couplings, or even for aviation use. There was, in fact, very little to indicate what the pipe
couplings to which the order related would be used for. There was a reference to “water, oil & glycol resistant
rubber” in relation to the first category of part number. There was a reference to “Rolls Royce” in relation to
the third category of part number. But there was nothing in the component drawing to indicate precisely what
sort of pipe couplings the second category of part number was for. In these circumstances, in my view, it was
reasonable for a general rubber manufacturing company to assume that the order was for a general purpose
part, i.e. not a ‘controlled’ part or aviation part. I accept the evidence of Cellular’s Managing Director who told
the Review that his company had had no idea that the order had been used in aviation until contacted by the
Nimrod IPT in late 2008.
94 DE&S SE DQA FF Audit Report No: 2008-1784-2, dated 28 January 2009.
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