Andre said:
It occurs to me that the descriptions here, reflecting what is actually known, are too fragmented to judge the cause of the accident.
If the flight recorders survived as well as the press reports claimed, there will be much more raw data than was published in that 4-page report.
But as with any scientific investigation, "data" is not "information" till it has been verified. I would expect there that will be a long process with several steps along the way.
First, to get a best estimate of the kinematics of the aircraft through the event - what path it flew, and at what orientation. There are clearly some issues to be resolved there with inconstient and missing data.
Second, to get a best estimate of the control surface positions and engine power output. The report does not mention any particular issues there, so that may be simpler than step 1.
Then comes the hard part, which is figuring out how to make all that data consistent with the laws of physics. Specifically, what wind speeds (horizontal and vertical) was the plane flying in, to make the control inputs produce the path actually flown. That could well mean several months of computer simulations, and possibly some ground testing or test flying to validate the computer models if they are being used outside of their normal range of input conditions.
Only then are you close to being able to guess
why the flight crew did whatever they did - and since they are not available for interview, it may never be more than a guess.
On the other hand a simplistic "cause: pilot error" doesn't achieve anything. Even if the cause was pilot error, you want to stop the same type of error happening again.
But in the end, I would not be surprised if the root cause would be the failure to avoid the thunderstorm after all.
From the small amount of data in the report, one of the first unanswered question is: from flying level at a normal cruisng speed and making a gentle turn, how did the aircraft get into a 7,000 ft/min climb for 3000 ft
after the first stall warnings? My best guess would be the first par of stall warnings were both false, and the plane had just flown into the top of a thunderstorm with a wind speed of at least 80 to 100 mph upwards.
I read that the pilots are not presented with a raw angle of attack indication. This is amazing for a fighter pilot, to whom the angle of attack is the most important feedback on the dynamix of the aircraft. Accurate angle of attack information could have prompted the pilots to take the right decisions.
The flight crew do have the artificial horizon and the climb and turn rates displayed, which are logically equivalent to the AOA, and for normal passenger flying more useful to meet the basic operational requirement - don't spill the first class passenger's drinks, especially if they are major shareholders in the airline.
