I understand that only ONE Nimrod has been modified (ducts and seals), and a new series 10 seal is being used. What was wrong with the old series 1?
It contains the wrong amount of carbon. I can't remember from the brief to aircrew if was too much or too little. Suffice to say, that a number of them have been found, on routine removal, to be split or similarly damaged due to incorrect carbon content. The damaged seals were not leaking at the time of discovery. Seems like the MOD was supplied with dud seals from the turn of the century. This adds weight to the probability of a fuel coupling leak on XV230, due to either misalignment (XV235 incident) or seal failure, rather than a 1 Tank blow-off.