Pinkman, taking note of the ice build up, do you conclude the ice derives from "in spec" fuel giving up its soluble water content in long duration cruise to block crucial lines at the engine? Because that's where I am. In your experience, isn't a simpler explanation poor fuel handling? As in, tanking, sumping, pumping, storing, etc.? Is it really the Trent or are other installs vulnerable?
Will, As a fuel guy, this is the way I see it:
They cant use the fuel recovered from the aircraft (would be gone very quickly) but they have tried VERY HARD to bung as much water as possible into the test fuel and STILL they have not been able to replicate the fault although they have seen icing. So while I still believe it was fuel related I havent seen anything yet that leads me to believe it was simply water in fuel. I want to know why the fuel FP was elevated over typical RP-3 even though it met the spec for Jet A-1. Do I believe the Trent before the mod was more susceptible? Yes. Do I think that other powerplants would suffer the same problems as the environmental conditions became more severe? Of course.
Regarding your question on handling, it doesnt really matter - if the fuel was on spec and was badly handled and became unfit for purpose despite being on-spec it is no different to it being unfit for purpose and well handled.
Cast your mind back to the Australian avgas incident which caused a plane to fall out of the sky and grounded the Victoria GA fleet. Trace amounts (parts per billion) of Di Ethyl Amine - a chemical that is used widely in refining to remove Sulfur, and something you wouldnt expect to be an issue - caused a wierd reaction with the metal piping / braze in some aircraft fuel lines. The fuel met spec. In this sort of incident it is simply not enough to say "the fuel met Defstan 91-91" or whatever. You have to take it apart molecule by molecule and look for things that you "dont know that you don't know".