TD: I only answered the general question you asked, had you asked that specific question I would have been unable to answer, the only people that can answer that specific question about XV230 are the groundcrew who would of actually signed a job card to do the duct replacement task, or engineering records who would have the card filed away.
DV: Noah had a crystal ball in the form of God, thats why he built the Ark before the flood. I believe the Nimrod personnel are working after the flood with regards to this specific problem i.e. in hindsight, with not much actual evidence to say categorically that we need to spend money on a specific 'Ark', allthough they have decided to go with the SCP duct replacement 'Ark' , again in hindsight after an investigation into one incident.