TD: Da4orce on the 28th June on post #663 posted the answer to those questions which where:
Recommendation
The ruptured duct is replaced with new manufactured items on a fleet-wide basis as soon as possible.
Action Taken
Recommendation closed. All such ducts fitted to in-service aircraft have been replaced with newly manufactured items.
Recommendation
The extent of the hot air leak warning system is reviewed to ensure that all possible duct failures are covered.
Action Taken
Recommendation closed. A review of the aircraft warning systems revealed that the affected Supplementary Cooling Pack Duct was the only duct whose failure would not have been detected.
Recommendation
A hot air leak warning system is introduced for the ruptured duct and cross-air bleed ducts.
Action Taken
Recommendation rejected. The duct failure was an isolated incident and was in the only part of the system where a leak would not have been detected. All of these ducts have been replaced with newly manufactured items that, based upon the previous 25 fault-free years that the original duct had been fitted, are expected to last well beyond the planned MR2 Out of Service Date (early part of the next decade). Moreover, fitting a discrete hot air leak warning system would be a complex modification that would have to be embodied across the fleet during its maintenance cycle and therefore take several years to embody. Considering the Out of Service Date of the Nimrod MR2, the fitting of such a system was not considered to be practicable. Action closed.
Recommendation
A maintenance policy should be instigated for the ruptured duct and all similar ducts.
Action Taken
A study into the need for a preventative maintenance/lifing policy for this and similar ducts has been concluded by the Designer (BAE Systems). Their report, which is due to be issued imminently, is based on the results of a detailed analysis of a sample of ducts taken from a number of MR2 aircraft. This analysis has taken time to complete, but the report is expected to recommend that a lifing policy be introduced. Ducts due for replacement would be replaced during scheduled maintenance activities and it is anticipated that such a duct replacement programme would be in place by December 2007. Action ongoing.
And before we get into discussions like last time, the lifing policy for the specific duct that ruptured, and has been replaced across the fleet already, see first recommendation/Action Taken, will be from post fitment of this new duct. For all other ducts that did not require replacement immediately, as they did not fail, the lifing policy will be as appropriate from the stated analysis of these other ducts, subsequently these other ducts will get replaced before this analysis indicates the time-line likelyhood of failure and that these other ducts will start being replaced, as required, starting in Dec 07 during a scheduled maintenance task.
TD I hope this helps answer those questions.