Phil G. - Indeed, an astute observation that the almost identical failure of two virtually independent systems within seconds of each other has the AAIB considering the probable root cause to be a hithertobefore completely uknown icing event occurring identically and almost simultaneously in both of the independent systems.
Iomapaseo - The report shows a schematic diagram of the fuel system which indicates a separate Fuel-Oil Heat Exchanger (FOHE) for each of the two independent engine/fuel systems which suggests that both FOHEs would had to have failed identically and almost simultaneously should FOHE failure be the cause.
Phil G. - With regard to a one-off icing condition affecting other certificated aircraft ,then in fairness to the AAIB and as quoted and pointed-out by FullWings, their published Safety Recommendation 2008-048 does state:
"It is recommended that the Federal Aviation Administration and the European Aviation Safety Agency should take immediate action to consider the implications of the findings of this investigation on other certificated airframe /engine combinations."
It would seem appropriate for the investigation to be considering root causes that would more plausibly (than prior unknown icing on this aircraft) cause both independent systems to fail identically and almost simultaneously. For example, causes that are common to both systems. Although it does appear from the continuing "data mining" exercise that the low temperatures for long time periods experienced on this flight do place it at the extreme end of all known flights for this aircraft type.
Last edited by Phil Rigg; 4th Sep 2008 at 19:07.
Reason: Bad typing and grammar!