Airfoilmod: We are still stuck with a philosophical foundation to the engineering. How do TWO separate, isolated and independently controlled systems exhibit virtually identical (Failure) behaviour simultaneously.
Please don't overlook the FACT that FUEL, ENVIRONMENT and PROCEDURES are common to both installations.
Why do you assume FAILURE?
It is quite possible that no FAULT (i.e. DEFECT) occurred in the homologated imstalation. Just that operating parameters (possibly even STANDARDS) were (are) inadequately specified.
I suspect that fuel QUALITY is a "Black Art" and to a large extent relies on standardised manufacturing process to control various aspects of quality.
Since the initial AAIB report I have been concerned regarding the low fuel freezing point on the sample taken from BA038. It sticks out like a sore thumb!
Maybe some of you guys can provide DATA on what the expected RANGE of this parameter is. If, as I suspect, the range is normally in the order of +/- 5 degC from whatever is the agreed "norm" is, then what made this fuel have such a spectacularly different freezing point?? OR is this very low freezing point understood, and simply a red herring?
The fuel may be "in spec" but something was unusual IMHO about the sample(s?) measured.
Whether this unusually low freezing point was due to something linked to the original fuel processing / additives or whether it was the result of some strange in flight stratification process remains IMHO an OPEN question.
Even if the low freezing point itself is not an issue maybe it highlights (indicates) a fuel with a greater propensity to cause cavitation or whatever.,
A reason exists for this near disaster! With all the data that exists I find it almost incredible to accept that a (potential) cause / sequence of events has not been identified.
OK it may take time to CONFIRM any such potential sequence of events but although we are struggling with inadequate data I'm convinced that this cannot be the case for the investigators.
However, the part of this that I don't understand is why no activity has occurred to put in place more rigorous procedures at least till the sequence of events is published. e.g. Tightening of fuel min temp or whatever.
So maybe the cause is understood and since the RISK of a repeat event is considered LOW there is no need to rush out a further report especially if this is POLITICALLY SENSITIVE in someway.
All will become clear in the fullness of time!