Originally Posted by snanceki
7 months and counting.
This incident had a cause. Period.
As all accidents, it had a number of causal factors. Never only one single cause.
The most surprising omission IMHO is why increased fuel temp monitoring / modified temp threshold value / increased water drain off frequency (or conditions) does not appear to have been introduced, at least on this sector or with this operator.
Fuel temperature:
Originally Posted by AAIB Special Bulletin S3/2008, P2
The lowest total air temperature recorded during the flight was ‑45ºC
[...]
analysis of fuel samples taken after the accident showed the fuel onboard the aircraft [...] had a measured fuel freezing temperature of -57ºC
And:
Originally Posted by B777 Flight Manual
Fuel Temperature
[...]
Fuel temperature will tend to change toward total air temperature.
As to fuel and water ...
Originally Posted by AAIB Special Bulletin S3/2008, P2
The fuel has been tested extensively; it is of good quality, in many respects exceeding the appropriate specification, and shows no evidence of contamination or excessive water.
... and:
Originally Posted by AAIB Speical Bulletin S1/2008, P2
A sump sample taken from the left and right main fuel tanks shortly after the accident revealed no significant quantities of water.
If water from the centre tank had played a role during the final approach, it would have to have melted earlier during approach to be scavenged by the main tank scavenge pumps to the main tanks, and thus water would have to have been present in the main tanks. This was not the case.
(I take it that the term "significant quantities" implies such a quantity that it might exceed the operating limitation of the water scavenge system (which is effectively a fuel/water-stirrer), the fuel delivery system, the pumps, and the engines.)
Maybe such an action has been taken although not reported.
Such an action would be a low cost "palliative" and would also add to data collection.
And what symptom, exactly, would this "palliative" treat?
Seen another way, it would be an additional cost, with no benefit.
Still not entirely out of the question is a software problem. It is very remote, but so is every other possible scenario that has arisen so far.
If we exclude every possibility that is "very remote", we must conclude that BA 038 landed safely.
Or, according to a well-known German poet:
Originally Posted by Christian Morgenstern
Die unmoegliche Tatsache
[...]
Und er kommt zu dem Ergebnis:
"Nur ein Traum war das Erlebnis.
Weil", so schließt er messerscharf,
"nicht sein kann, was nicht sein darf."
(A translation from
Christian-Morgenstern.de:
The Impossible Fact
[...]
And he comes to the conclusion:
His mishap was an illusion,
for, he reasons pointedly,
that which must not, can not be.
)
Bernd