Operational changes ahead ... and redesigns!
Warning: I'm non-professional; not crew, not engineer - just scientist guest and thanks.
Hello again,
Referring to the Andy Pasztor article in WSJ, post 908, and my post 751, 'What if no proof of cause - what does the AAIB do?' when I wrote:
"I've been wondering what would the AAIB do if they could not demonstrate to a high probability the cause of the accident. If, for example, the AAIB were convinced, but could not prove, that the fuel quality had been lowered by cold-soaking for an extended period of time and that this had lead, in some unknown way, to the accident, what would they do?
Presumably the AAIB would operate on the precautionary principle.
Might they:
1) Recommend/demand/regulate the avoidance of extended flight-time in very cold air masses;
2) Demand that if aircraft had experienced extended flight-time in very cold air masses then they must
loiter for some time in warmer air before descending for landing?"
I'm going to assume David King of AAIB is fairly certain that fuel degradation due to cold-soaking for extended periods of time is the root cause of the accident and that his quotes in the above article are accurate.
Then David King would seem to be trying to gather support in advance for a set of operational recommendations that he knows, or suspects, the industry will resist. Presumably he is not acting alone and, hopefully, will already have significant political support, albeit presently hidden below
the palisade.
Fact is that demonstrating by experimentation that fuel degradation was the result of operating conditions will take years. In the meantime, the industry should soberly reflect on the continuing lives of 152 souls and consider the accident a clear warning that, as has been the case so many times previously, and in most arenas of human endevour, we don't know it all!
So I think that in a few weeks there will be recommendations from the AAIB (and others) that operations in 'polar regions' must change.
And my predictions for the years ahead:
1) Fuel stratification will, by experimentation, be shown to be the direct cause of the accident (see post 241).
2) Aircraft will have systems (probably laser based) to detect ice/sludge etc. in fuel tanks. These may be retro-fitted to aircraft that fly ETOPS.
3) New fuel heating systems will be mandated for all new aircraft designs, that is, the fuel will be heated in the tanks and will not rely any longer on the downstream heat exchange systems returning the fuel to a non-degraded state.
Regards, Tanimbar