Well geez, just have a loud klaxon with a loud voice saying "AUTOPILOT DISENGAGED", along with a reading as such on the PFD until it is acknowledged by the crew with a switch? Like a dead-man's button on a commuter train, so the engineer can prove he's still at the controls and has situ.
I can give you more information about what Boeing said on that subject from this article published in Bloomberg: https://www.bloomberg.com/news/arti...ulletin-for-737-max-after-indonesia-jet-crash. Apparently, right after the Lion Air crash in Oct. of last year, Boeing actually issued a bulletin about the faulty angle-of-attack sensor that put the anti-stall system into overdrive and nose-dived the plane. And just like you said and also confirmed by Boeing in the article that this anti-stall system malfunction can happen at any time whether it was during autopilot or manual flying. It's just that in order to override the computerized autopilot, according to the article, "pilots can counteract it by pushing a switch on their control yoke. But the plane’s computers will resume trying to dive as soon as they release the switch, the Boeing bulletin said. Flight crews should follow a separate protocol to halt the plane’s potentially dangerous action, according to the bulletin. Pilots are supposed to memorize a procedure to disengage the angle-of-attack inputs to the plane’s computer system." So basically even if the pilot is trying to override the autopilot, it can do so temporarily by depressing on this "switch" and as soon as they let go, the autopilot takes over again. And in this article, it states that FAA had given airlines 3 months to update their flight manual to include this "procedure" for the flights and yet it never stated what the "procedure" is and how it's connected to this faulty sensor. https://www.bloomberg.com/news/arti...-black-boxes-will-go-to-europe-737-max-update That to me are all are very irresponsible of Boeing and the maker of the sensor, United Technologies, another company's stock that should be shorted. Because if there is a lawsuit, United Technologies would definitely be in the plaintiff's list. It produced a plane and only after a deadly crash, it came out and said "oh btw guys, the angle-of-attack sensor that's part of supposedly a safety feature is bad and can act up at any time and basically crash your plane. So what you do, you just ignore everything that the plane is telling you and fly the plane like the plane is from 1970's, the good old days ok? We are not going to fix the problem or repair it or update it in any way because we do not think that's a problem. Our planes are always perfect like God and never have problems even when we see there is a problem, there is no problem. We are just telling you that this sensor doesn't work properly at times and good luck". This was basically what Boeing said and did in a nutshell, with arrogance and complete indifference to safety and potential loss of human lives. To them, everything is about $$. Way too costly to recall every single plane sold, repair the sensor or update the software. Much too cheap just to issue a "bulletin" then my responsibility is done. You can't figure out how to correct it in time, in mid-air potentially tens of thousands of feet in the air, that's your problem.
Except in this case the angle-of-attack sensor that's supposed to detect this "stall" situation that can cause crash was not detecting correctly. There was in reality no stalling but the sensor "thought" it was stalling and over-compensated by the nose-diving. Yeah I understand the mechanism of how it works. At the end, it is still Boeing or actually United Technologies, the maker of this sensor's fault for making the faulty sensor that rendered this "stall-avoidance" system not just useless but dangerous and their refusal to repair or fix it or update it even after the Lion Air crash last October just makes them criminally negligent really. The more I read about it, the more I am actually angry at what Boeing and United Technologies did and did not do. They should be charged with criminal negligence causing death. But knowing it's Corporate America, of course nothing is going to happen. The investigations will probably be delayed into oblivion (the Lion Air crash happened last Oct., almost half of a year later, it's still ongoing) until everybody forgot about it and resumed in taking plane rides on those planes and then even if the true and full results is published nobody would care anymore. And if Boeing and/or United Technologies are found to be at fault for anything, the most they will get is just a slap-on-the-wrist fine. Except all of the victims' families and loved ones would be stuck forever with the pain of losing their loved ones but who cares? How much do their lives cost? As long as Boeing makes money, that's all that matters.