Originally Posted by
Luc Lion
Oggers,
re-read parallely the abnormal procedure AND the interim accident report.
You'll conclude that the pilots have followed the procedure until flipping the cutout switches.
And, in the accident interim report, you can read:
05:39:56: auto-pilot disconnects
05:40:00: MCAS kicks in and trims down for a duration of 9 seconds
05:40:13: the pilot trims up for 3 seconds
05:40:21: MCAS trims down for a reduced duration of 7 seconds (interrupted by the pilot trimming up)
05:40:28: the pilot trims up for 10 seconds
05:40:38: end of pilot trim up action. Somewhere between 05:40:38 and 05:40:43 the cutout switches are actioned.
05:40:43: the next MCAS activation doesn't move the STAB.
So:
- As per item number 2 in the check list, the pilots did control the airplane with control column and main electric trim after noticing the uncommanded trim behaviour.
Then, as the runaway continued, they actioned the cutout switches (item number 4)
- The whole sequence took place in 43 seconds.
If one has plenty of time to consider the situation and choose the best course of action, he could read the point 4 in the check list as
Unfortunately, if one is shaken and startled, it is the written list that will be executed.
Mate, I think you have lost the plot. What you wrote was:
There is nothing in the FCOM nor in the QRH that instructs to use electric trim buttons to put the aircraft in trim prior to flip the cutout switches,
even though I reckon that, calmly sitting in a chair in front of a computer, it looks like a good idea....The only information akin to that is in the airworthiness directive AD 2018-23-51
...so let me repeat:
the advice to control pitch using electric trim has been in the NNC for 19 years now. It is number 2 memory item. Furthermore, the amplifying remarks promulgated with the AD were a de facto amendment to the FCOM that the operators were required to action within 3 days.
Your latest post is tilting at some windmill. But go ahead and explain why you think it means that the advice to use electric trim is not really in the NNC and the information in the AD was not an amendment to the FCOM after all......