Gums,
Your posts and experiences on FBW aircraft have been extremely enlightening and most welcome as the PPruNe pilots and technical contributors continue to explore the factors causing the demise of AF447. There is no apology required for your conclusion that a certain amount of cause should be laid in the lap of the aircraft designer/producer. As
Smilin-Ed points out, there are more causes that will/should be identified in the end. The facts are, things have changed from times ago. Then, there were basically two failure causes, airplane failure (the wing fell off or the engines quit) or pilot failure (poor judgement). Now there are multiple causes besides these two, computer failures, computer logic failures, computer messages that say one thing but mean another, nonexistent training for events that occur and the overall reliance on a man-made system that is deemed to prevent human error while ignoring the possibility that a system error could result in the same disastrous conclusion. The sophistication of today's FBW aircraft now translates into accident investigations, they in turn, become far more complex in determining root causes and recommendation measures.
I see quite a few people believing that substantial information will be forthcoming in the next BEA Interim Report, even some have mentioned causes being stated. I think the bar of expectations is set much too high in this regard. To date, we have received 50 pieces of a 750-1000 piece puzzle. In examining our 50 puzzle pieces, there is a diversity of opinions, theories and proposals as to what these 50 pieces represent. Now think about the BEA folks. Although they are "experts" in accident investigations, probably none of the investigative members are actually experts in the workings, flight handling and technology nuances of the A-330-200 aircraft, human capability under data overload and extreme stress, let alone its FBW system and logic. So they are dependent on contributing experts to assist them in analysis of all the data recovered, plus the recovered components of the aircraft and (sadly) the medical reports of the recovered passenger remains, human factors, pilot training, airline management decisions regarding available equipment and equipment up-grades. This is not and should not be a whizz-bang investigation reaching conclusions and disclosing information or data that is not clearly understood or where consensus has not yet been reached. IMO, the next interim report will give us another 50-75 pieces to examine. There is always the possibility of something of immediate concern being confirmed that will produce a safety recommendation. I don't look for much more.
Once all the data the BEA possesses has been thoroughly wrung out, tested and agreed to, can the process of assigning cause begin. IMO, this is the most difficult phase for committee agreement as it involves significant thought, logic, agreement consensus and legal implications (knowingly or not) going forward. There are different degrees, causes (primary), contributing causes (secondary), and undetermined causes (not enough data to determine). For a cause
discussion example, Airbus
now states:
For a given configuration, a given speed and a given altitude, Lift is only linked to AoA
For a given aircraft configuration and speed An aircraft stalls for a given AoA
Stall is only an AoA problem
When did Airbus know this? Was AOA available and in the
forefront of presentations to the pilots in a moment of severe duress on AF447? If not why not? Is this a primary cause, a secondary cause or no cause at all?
IMO, I don't look for a final report from the BEA for a long time as they sort through everything.
Regards,
TD