Pacplyer, you're being a bit unfair to the investigators.
TWA800 did not take 10 years. There was a Public Hearing after 17 months where all the main evidence was set out. Judge for yourself whether it was a useful exercise (NTSB Chairman's statement
NTSB - Statement by Jim hall 12/12/97 and contents list
NTSB - TWA 800 Public Hearing).
I am sure that the work to model the 777 fuel system and examine flight data is taking time for scientific reasons, not because industrial or political pressure is being brought to bear. It is quite possible there will be a big wrangle about liability etc later on, but I have confidence that as soon as the AAIB have narrowed the probable cause of BA38 down enough to be able to issue safety recommendations they will do so - they don't need to wait til the Final Report, and they would be judged harshly if they 'sat on' something important - I am sure they would not do that. As Precept said at the start of today's discussion, if it is looking likely to be cold-related and if BA38's exposure was unusual (I don't see why it has to be unique - other factors could have been involved which could recur) then it would be reasonable for AAIB to issue to recommendations on flight in cold conditions before winter.
Back under my stone.