CLA is wrong in assuming this problem was not spotted by designers.
"Naturally the Nimrod's designers realised that 400-degree compressed air is stuff that ought to be kept separate from essentially everything else, so the pipes are heavily insulated.
Just as naturally, the insulation is only replaced if it goes wrong; the maintenance handbook does not state how much insulation is tolerable. An experiment on a dodgy section showed the insulation was only 16 degrees cooler than the bare metal. "In some areas on other aircraft it was noted the laces have loosened and there are visible gaps between the blanket edge and the main pipe insulation, leaving exposed sections of pipe surface", said the Board."
This was a contributory factor noted by the board.
I agree with Mr P the air in this pipe fulfills a number of functions. Would CLA confirm that Nimrod is no longer operated on 2 engines because there is not enough air to start another engine if one of them fails?