"Runaway Trim" checklists are designed around an event of the trim running continuously in one direction or the other, with the yoke trim switch being mechanically jammed internally toward completing the circuit toward either direction. But this was not that scenario -- the trim was only moving intermittently because the MCAS can be interrupted by actuating the yoke trim in the opposite direction momentarily -- stopping the MCAS for a five second interval until it starts again for up to 10 seconds, unless it is again interrupted. That's what happened about 20 times as the crew struggled to analyze what was happening. That's why they went so long in near-level flight, until the MCAS finally actuated long enough to reach full down-trim (first officer had likely just taken control at that time during the last couple of cycles of the MCAS). And the runaway trim scenario taught in the simulator doesn't piggyback on top of a continuous stick-shaker indicating a stall -- that is a compound emergency not addressed in the simulator. The result is a lot of confusion in the cockpit (and maybe compounded, as you said, by cultural/language barriers). It's unfortunate that the crew didn't think of using the Stab Cutout switches, but given the intermittent nature of the MCAS-actuated trim, the fact that the manual trim could not override the MCAS (trim controlled by MCAS still moves opposite trim wheel manual movement), the compressed time factor, and the fact that one or both of them had to struggle to keep the nose up due to yoke forces, it isn't too much of a surprise that they didn't run a checklist that was perceived as secondary to the first problem they experienced with the stick shaker on climbout (and remember at first there was no MCAS activation during initial climbout since the flaps were still extended).
Pilots are right to be upset that Boeing kept this feature of the Max a secret, and Boeing will have to learn it's lesson the hard way. I doubt Boeing will get much sympathy from the public by blaming the crew or by blaming LionAir's training program.
OR more importantly the instrument transfer switches
Which instruments would have made a difference?
Excellent description. Thanks for writing that.
Question...if they went through 20 on/off cycles of the the hor stab trim actuation by MCAS, why wouldn’t they have turned off the Stab Cutoff switches? They must have been exerting tremendous physical effort to pull back on the yoke as you say, but wouldn’t a serious pitch control problem like this have led them to cut off / disengage the hor stab drives?
Re: instrument transfer switch . . . you ask . . . Which instruments would have made a difference?
The report from Aviation Herald states . . .
"the right hand speed (first officer's IAS) significantly higher than the left hand speed (captain's speed). The captain's AoA indicated about 20 degrees higher than the first officer's AoA."
Considering each side of flight instruments are independent of each other, if the instrument transfer switch does not work, then we have a double AoA failure and or double computer failure (not likely) and so far I have not heard anyone is suggesting that nor apparently does the FDR indicate that was the issue. Of course with the AoA, by the book go immediately to the tie-breaker . . . the standby attitude indicator. Reading the report, says the left side, Captain wrong, so switch to first officer side.
Report only says first officer side airspeed "significantly higher" does not make it wrong. Captain airspeed could be wrong. Tie breaker for speed is "standby indicator" and/or set a known power setting and at least we are in the ball park.
You are correct in that a "low speed" runaway stab trim is continuous, but you have to admit it is slow and feels intermittent. However, I agree with ProtectOurFreedom regarding stab trim. . . . all the flight crew had to do is look down at the stab trim setting and see the Stab Trim position indicator is beyond the green band (normal).
Only lack of proper training would any crew just sit there and say say "oh wow" gee I just have to pull on the yoke harder. At least grab the dang trim handle and start cranking. (proper training, not instincts). If it rolls forward again, as it did, without knowing anything about MCAS, all I know is my stab trim is screwing me up. Pretty sure we don't need a book to tell us what to do.
I agree with you and we both understand the amount of confusion going on the flightdeck in those moments. The noise alone of the original auto-pilot aural warning, followed by the stick shaker and then of course the GPWS aural warning pull out pull out er I mean pull up pull up requires a level of mental discipline to remain focused.
I agree with you on "compound emergency" which I refer to as a single source failure effecting several systems resulting in a lot of confusion. Admittedly, I have seen experienced crews in real life fail to identify that a single source was causing multiple failures. In each event, the source of confusion could easily be traced back to inadequate training, including many cases, the failure to execute good CRM and manage the flight deck properly. With the noise, lack of proper communication, dealing with the "result" of an abnormal, not the cause (source), unable to prioritize and manage the flight deck properly, they literally flew the airplane into the ground.
Another issue (I have many more I issues that I could address LoL) One has to ask the question, were they surprised? Startle factor? And most folks would probably say yes. But that begs the question, why? Surely they saw the problem written in the aircraft log book twice. (Or did they?? If not why not??). Had they seen it written in the aircraft log book, surely they would have briefed themselves what actions they would take if the same event occurred again. Thats just basic threat error management.
The above and much more is why the finger is being pointed to Lion Air training program