I did read it, he said “So both STAB TRIM CUTOFF switches get relabeled rather ambiguously PRI and B/U, and both get the same functions - equivalent to the old STAB TRIM CUTOFF MAIN ELECT switch”
They do not have the same function as the NG, nor do the have the same function as each other.
Please, do share. Looking at the functional diagram
I wasn't able do discern a difference in function between PRI and B/U switches (they are wired in series, and opening either will cut power to the R64 stab trim control relay, therefore disabling the electric stab stab trim). BTW on the diagram the switches are labeled A and B: do you happen to know which is PRI and which is B/U?
The rest of his post is factually incorrect. The NG was originally certified without the low speed stall function, that was added afterwards without the need for additional training. JAA insisted on the low speed stall function, it was added as a mod.
I am sorry my post did not get the meaning across clearly enough: I was conjecturing about the "genesis" of the MAX, not of the NG.
Sounds far fetched, but *if* that's true, it's possible that the initial approval of the design approach was legitimate, all failure modes analysed etc. based on that maximum deflection.
Just to be clear: I personally do not think that this hypothetical "initial" design iteration would have been legitimate. An airliner certified in 2017 should *not* give up all flight envelope protections on a single sensor failure. However, it would still have been much better (and safer) than an airliner vulnerable to a catastrophic control runaway on a single sensor failure, unless pilots with exceptional deductive skills and physical strength react within seconds with a specific sequence of actions.
I can't figure where exactly in the sequence the step-up in MCAS control authority from 0.6°/cycle to 2.5°/cycle happened, and how it got "lost" in the communication with FAA. Could be as much a smoking gun as the hidden functional change to STAB TRIM CUTOFF switches. IMO either would be enough to warrant a full revision of the certification process.