JFZ90, I should make it clear that I have a number of engineering sources each with varying levels of expertise. I sometimes find it easier to quote word for word because I am not an engineer and there is little room on this thread for error.
The whole subject is confusing for contributors interested in what happened to XV230 but not really sure who to believe. The passage in my last post was an informal comment as you quite rightly pointed out. In an effort to understand the situation I have been asking a lot of questions, some people at Kinloss have kindly helped as well.
With regard to TWA800, I can't really comment except to say that design engineers are now approaching the problems of fuel tank explosions in airliners in two very different ways. Witness the incredible amount of engineering that has gone into Airbus A380 and Boeing 787 Dreamliner, two markedly different engineering solutions.
I favour the Boeing approach which is to still provide a version of OBIGGS just in case. It is worth noting that the spec for dry bay protection in Nimrod can be traced back to 1981/2.
I don't buy the idea that Nimrod is safe just because obvious forms of ignition have been removed. There are many remaining issues Angus Robertson has asked for a detailed account of where we are in each of the QQ recs. There is a real need for the MoD to explain where it is right now, otherwise confidence will continue to ebb. One of my aims which I stated a long time ago is that military aircraft are routinely given fuel tank protection. A no brainer. I am deeply saddened that there is still no protection on MRA4.
There are big arguments to be won here, They might have to be won in Court. But when you witness the two fingered approach from Bob Ainsworth in reaction to the Coroner's verdict, and from RAF Chiefs of Staff RE the Nimrod flypast I have little sympathy and little confidence that the MoD is capable of being taken seriously as an airworthiness enforcer.
I will look into TWA 800 recs. I am aware of FAA proposed legislation I am also aware of the very simple fix that is now used on 747 400 to mitigate the threat of centre wing tank explosion. I will post back anything here of note.
With regards to the risk to passengers `I can tell you that I doubt if any airline in the land would fly passengers around in an aircraft deemed non-airworthy. As a result, Bob Ainsworth has placed himself in a very exposed position.
Eventually I believe that all airliners in the States will have fuel tank protection. The modern systems are very light-weight and efficient. There is obviously a balance to reach. And I have some sympathy with the argument that Nimrod is much safer now. That said I have no faith in the implementation of airworthiness regulations. Witness the fact that AAR continued til Nov 2007 long after QQ reports had been posted.
It is important to understand the relationship between, and roles of, the RAF maintainers, FRA and the IPT in the context of Nimrod line servicing. I would welcome a post from someone who understands the relationship. I confess my own knowledge is weak in this area. I do understand that merely placing 2 organizations side by side will not solve anything if there is an inherent lack of skills, experience, training etc.
Edited to add, JFZ90,If you've not looked already, the following might be of interest:
SFAR 88
Airworthiness Notice 55 issued by the CAA and EASA
Google those lines and a lot of information comes up: bottom line (one
of them)is that on modified fuel systems a lot of work / rework needs to
be carried out with regards to reducing risk of fire / explosion. This
is not only on old Aircraft, but also on more modern ac, eg BBJ (based on the B737-700). Operators that do not comply will have to have the Aux fuel system made inoperable.
Part of this mod is to install "dual wall" fuel pipes. At present, it is allowable to shroud a standard rigid pipe with a larger flexible hose type assembly, with a gland drain that can indentify the source of a leak to within a certain distance. The hose will go.
The MRA4 should be built now to Civil Standard, but of course, it does not even have dual wall fuel pipes. It also does not have probe inerting, fuel tank inerting systems, under floor fire protection, bomb bay fire protection, FDA, etc etc. This argument is as much about MRA4 as it is about MR2, but again nothing but deafening silence from MoD...........
Last edited by nigegilb; 22nd Jun 2008 at 23:52.