DV:
So I say to the guys who are still flying, ask what mitigation is in place to cover this level of risk.
And I say to you, DV, that you are going into areas that you know little or nothing about. You are viewing this risk too simply. High Pressure (HP) air ducts exist in all jet engine compartments, worldwide. They all have joints that might fail, never mind corrosion and they all have the same type of mitigation (detectors). Anyway, regardless of the mode of failure, all of the HP ducts on the Nimrod that are charged in flight are within the fire zones of the engines. I don't have any argument with the upgrade from "remote" to "occasional", in determining the rate of failure. However, a more accurate assesment of the effect of a single duct failing in the most dramatic manner would be, "inconvenient" at worst. All of those ducts are surrounded by titanium panels and the engines themselves. Although they are also routed outside the engine compartments, they are not charged with any air in flight.
To confirm my point: Worst case: during take-off one of the ducts bursts and the associated engine loses some power. There might even be some damage within the engine compartment. The power loss leads us into well rehearsed reactions which lead us into a safe mode of operating the aircraft. A warning will be received on the flight deck and the engine will be shut down and the duct will become dead. A single engine shut down will never be a hazard to a Nimrod. If there was any damage within the engine compartment it will be engine associated but the engine is not now running, so its inconsequential. Catestrophic (loss of aircraft)? Thats a ridiculous assessement.
QQ are not Nimrod experts.
Regards
Ed Sett