Following an editorial comment in Aerospace (the RAeS monthly publication) in the Sept edition a letter by Tony Blackman followed a month later.
Tony Blackman FRAeS letter as it was published here provides a useful insight :-
MAA and Nimrod Ref the article on the MAA(2) there can be little
doubt that military air safety has been improved by the Haddon-Cave Report
but, unfortunately, it was done unnecessarily at the expense of the Nimrod by misidentifying the source of the fi re. Sadly nothing can bring the aircraft and the crew back but the fact remains that the Nimrod crashed not by having a fundamentally bad fuel system as suggested in the Report but by lack of flight testing and not understanding the prophetic warning given by BAe in 1985: ‘There may be some cause for concern with regard to the wetted surfaces caused by a discharge of fuel and it is suggested that tests are made in flight using a coloured dye to study the behaviour of liquid in relation to the various ports and intakes, particularly the tail-pack pre-cooler in the bottom of the rear fairing. If the liquid is found to enter this intake, it may be necessary either to switch off the tail pack before commencing air-to-air refuel, or to carry out a modification on the blow-off valve outlets of
tanks 1 and 6 to prevent the fuel running down the skin.’ It is remarkable that the BAe warning was ignored not only by the firm itself but also by the
MoD. The Haddon-Cave Inquiry found this report but did not understand
its implication which warned that blow-off fuel might be going into the pre-cooler intake where the temperature was 400°C and any fuel would immediately be set alight. From the accident investigation evidence which showed that the tail-pack warning occurred first followed much later
by the bomb bay fire warning it is clear that that is exactly what happened
to Nimrod XV230. Had the cooling pack been switched off the accident
would never have happened. There seems to be universal acclaim for
the Haddon-Cave Report but it is interesting that no attempt was made by the Inquiry to find out where the blow-off fuel from the tanks actually went by carrying out simple tests. It could be argued that had the real reason for the tragic loss of the Nimrod been appreciated the pressure to cancel the project and leave the UK without a maritime military aircraft might not
have been so great.
Given his prior comments on this could make for an interesting night:-
http://www.blackmanbooks.co.uk/fpdb/nimrod%20XV230.doc