Lots of emotive responses and "opines"........
The Boeing 737,on balance,is a remarkably safe design.
Manufacturers cant be praised one day for a stick shaker helping a pilot identify a stall and the next day be blamed for that same stick
shaker causing confusion and masking if its input is false..One accepts the good with the bad.Its an imperfect world.
Anti-stall and speed stability devices are desirable and mandatory for certification.They require inputs.These inputs are dependent on the
reliability of the pitot static system.That system is not invulnerable.Checklists,procedures and a pilots airmanship will overcome a UAS event.
The level of airmanship in pilots,like training and experience,is very variable.Nothing is guaranteed though.Highly competent crews can and do make mistakes.The human species is entirely fallible.
Manual raw data flying skills are at an all time low in the industry.Many pilots are highly automation dependent.This is a worrying trend and needs
addressing.
Many airlines prescribe more automation dependence via SOPs and mistakenly see more automation as a panacea for incidents/accidents.
Note that all Lionair B737s are fitted with Honeywells RAAS.An automated system to remind pilots of how to fly an airplane.....does it make sense to you??When they invent something like that,you know somethings wrong in the system.Some pilots perhaps who have logged 5000 hours on type on line may have manipulated the flight controls manually for 50 of those 5000 hours.No wonder then they need RAAS and FDs and AT and AP.This oversight can cause problems during non-normals when proficiency in manual flight will become the difference between life and death."If I hear I will forget,If I see I will remember,if I do I will understand"(Confucius)
Lionair maintenance failed to rectify a very high priority glitch in 4 consecutive attempts.After the 1st failed attempt to repair the glitch,the plane should have been grounded and subject to a test flight before further revenue flight.Lionair maintenance will be looked at very closely to be sure.If you think you can save money/time in maintenance,try having an accident....you may find that soon you dont have a fleet to maintain.
STS is poorly understood and seen as a nuisance by some pilots.Its not.Its required by certification and serves a valid purpose
FCC A controls both STS and AP stab trim on 1st flight of the day.FCC A gets data from Left ADIRU.If that data is corrupt,you will get unwanted incorrect trim.
STS trimming using bad data will trim to the stops if the pilot does not intervene.
Startle factor can occur if crews are insufficiently trained/experienced...this will lead to mental capacity overload and panic....repeated attempts to engage the AP are a sign of panic in UAS.
The STS trims using the quieter slower AP stab trim motor.Its not a runaway technically as its intermittent.If aural/tactile warnings,like stick shaker,are operating the crews ability to focus and THINK(never mind intuit) will be effected.They will pull on the stick and use main electrical trim to trim up,both of which will override but not disable the STS.They will think they are in control but as soon as they stop,the STS trim down returns.
The Boeing AD addresses this by an emergency order to KILL ALL TRIM by putting both stab trim cutout switches to cutout(RUNAWAY STABILIZER NNC).If they make it a recall item,then the pilots no longer have to think do they.......thats about where we are in aviation these days....Pay to fly,tick the boxes instructors,no pilots at board level,automation dependance gone awry,B777 pilots that cant land on a clear day in SFO without a glideslope signal.....yep,that just about sums up where we are......Rananim sends or opines....whatever the hell that means