I was interested to read something that I was pondering over but could not put into words,
and then someone sort of did:
Originally Posted by EDLB
I take bets that it has something to do with the signal wiring form the AoA vane to the flight computer (ADIRU) like shorting out one half of the SIN or COS symmetric signal and creating with that something around a 45 degree/2 offset. If the Ethopian airline FDR does show a similar problem, then there is some latent harness, connector or ADIRU problem which will show up in the other 737 MAX made in a similar timeframe. So if that establishes, the investigation might look into some of the grounded planes build in similar timeframe.
I have experienced weird wiring anomalies in a number of aircraft, and a few avionics systems, that frustrate the maintenance troubleshooters for days and weeks.
I've also learned about how "certain batches of finished work" can be recalled.
If the AoA unit itself is an industry standard piece, it may be that the signal (upon arriving at the computer brain) has gone wrong. The trace that shows one AoA signal going high and one steady on makes me wonder if there isn't signal contamination ... a condition which can be a real bugger to isolate on the ground.
Just a thought.
For an automotive defect that was a real pain to trouble shoot ...
My sister in law's ford excursion (big V 8 engine) would not and could not keep the AC on. but the problem wasn't in the AC system.
One of the coils was bad, so only 7 cylinders were firing. The computer brain in the car thus cut out the AC automatically as due to the engine running roughly/badly, and all of the signals not lining up in nice lines when arriving at that little brain. It's almost as though Ford's version of HAL was saying ...
You want the AC? I can't let you do that, Danielle ...