Originally Posted by
safetypee
A further hobby-horse in the article is a pilots display of AoA.
This theme also is taken up with the report of Southwest retrofitting the display option, quoting their reasons as:-
“… guard against any erroneous sensor data that may activate the jet’s controversial stall protection system.”
“… a valuable supplemental crosscheck in the event there is an erroneous AoA signal present” **
Knowing you have an AoA problem means you might more easily disregard a stick shaker when it doesn't make sense.
Also on takeoff roll crosschecking speeds AND AoA seems like a sensible idea.
I'm not sure any of that would have helped in this case. Not sure if the pilots in question ever had a simulator session with let's say a faulty stick shaker.
(Also announcing runaway trim before running the simulator training for that seems like a bad idea but that's my understanding of how simulator training is done)
Their obsession with going fast to the extent of overspeeding the flaps suggests to me they didn't even run the UAS checklist.
(edit: maybe more importantly no constant thrust was set but was changed frequently according to the FDR. this would only happen after the UAS checklist if they determined they could rely on the speed reading in some way. which begs the question why they were going that fast then)
Apart from that the AoA disagree display could have easier landed in the maintenance log filled out by the pilots.
Also the replacement of the AoA sensor introduced the problem in this case.
Before the replacement the captains AoA sensor signal was probably intermittent leading to altitude and speed being displayed as blank.
So with an according tech log entry maybe the AoA vanes would have been checked after the first flight where the AoA disagree was properly handled.
Just flushing all errors when the AoA vanes disagree seems like a maintenance action that is really strange.
Not sure what the maintenance manual says but it seems to me like that's a bad idea.