The Nimrod Review - Official Documents

5.128
Chapter 5 – Leak from Fuel Coupling
In my view, a proper material specification for the Avimo seals ought to have expressly specified: (a) that the
part was for use in an aviation fuel system; (b) the key physical properties required; (c) the chemical composition
required and actual polymer; and (d) the minimum life required. The original Avimo Drawing was not a proper
aerospace specification.
Obsolescence and failure to reassess the Avimo Drawing
5.129
The problem with the Avimo Drawing was compounded by the fact that the inadequate material specification
was never clarified at any stage; neither after the original Avon mixture referred to in the Avimo Drawing
was banned in 1964, nor after Dunlop stopped manufacturing the replacement material in 2000 and a new
manufacturer had to be found. As the audit carried out by DE&S identified, it is a matter of concern that, in
the 60 years since the Avimo Drawing was produced, nobody within the MOD, Avimo/Thales, or indeed any
of the other parties in the sub-contractor chain (see above), appears to have ever reconsidered whether it was
necessary to replace, or at least update, such an old component drawing. More care needs to be taken in
relation to old component drawings for ‘legacy’ aircraft.
Lack of any effective quality control
5.130
5.131
5.132
The second feature of particular concern regarding the non-conforming Avimo seals is the apparent total lack
of any real and effective quality control in the Procurement chain, comprising the M&GS IPT, Contractor A,
Contractor B and Avimo/Thales, notwithstanding the various Certificates of Conformity, etc., discussed above.
It is not clear, however, precisely who was responsible for what. The Aircraft Commodities IPT had apparently
believed that the M&GS IPT had aerospace engineers in their chain and that the M&GS IPT was the QA authority
for the Avimo seals procurement contract and were, therefore, managing all aspects of QA. 98 The M&GS IPT,
on the other hand, apparently took the view that it only procured for the Aircraft Commodities IPT, and that
the Aircraft Commodities IPT were responsible for the QA and Engineering Authority (EA) and Safety Assurance
(SA) aspects of the items that they managed. Regardless of who in fact held the QA responsibility, the Aircraft
Commodities IPT acknowledged that it was “extremely unlikely” that a QA assessment of Cellular had been
carried out by either the M&GS IPT or the Aircraft Commodities IPT.
This would appear to be correct. The evidence provided to the Review suggests that Contractor A, Contractor
B and Thales relied simply on sub-supplier controls, which established a capability to produce a type of product,
and then relied on the Certificate of Conformity produced by the sub-supplier as evidence of the satisfactory
completion of a purchase order. It would appear, however, that Contractor A and Contractor B had no real
knowledge of any item they were ordering beyond its part number. In my view, it is plainly impossible for any
effective quality control to be exercised without some involvement in, and understanding of, the technical
content of an order and a process of checking and sampling where necessary.
In my view, however, the lack of effective quality control exercised by the companies involved is primarily a
consequence of an overly convoluted and inappropriate procurement chain in which the MOD contracting
party (M&GS IPT) had no specialist aviation knowledge and the ultimate manufacturer (Cellular) was not even
informed as to the intended use of the product.
Price mark-up – 300% to 823%
5.133
As indicated above, the price that Cellular charged Avimo/Thales for the seals varied between £3.35 and £15.00
in respect of different part numbers between 2000 and 2007. The price that Thales charged Contractor B in the
equivalent period varied between £8.06 and £100.00. The price ultimately paid by the M&GS IPT was between
£15.29 and £123.50.
98 DE&S(Air)(Wyt)508324/120/1.
101