1. an absolutely enormous cost, like a couple orders of magnitude more

2. several years of delay

3. pilots would have to be completely retrained

4. the airlines liked the 737 very much

5. mechanics would have to be retrained

6. the inherent risk of a new, untried airframe

There was nothing at all inherently wrong with the concept of the MCAS system, despite what ignorant journalists wrote. What was wrong with it was it was not dual path, had too much authority, and would not back off when the pilot countermanded it. These problems have been corrected.

Pilot training - there have been many, many airplane crashes because pilots trained to fly X and Y did the Y thing when flying X. The aviation industry is very well aware of this. Boeing has been working at least since 1980 (and likely much earlier) to make diverse airplane types fly the same way from the pilot's point of view. This is because it is safer. And yes, it does make pilot training cheaper. Win-win.

> You claim "it's not hard". Sorry, this is just a bad mindset.

Yet it's true. Read about the first MCAS incident, the one that didn't crash. There were 3 pilots in the cockpit, one of which was deadheading. The airplane did some porpoising while the pilot/copilot would bring the trim back to normal, then the MCAS would turn on, putting it into a dive. Then, the deadheading pilot simply reached forward and turned off the stab trim.

And the day was saved.

I've seen your points many times. They are all congruent with what journalists write about the MAX. Next time you read one of those articles, I recommend you google the author to see what their background is. I have done so, and each time the journalist has no engineering degree, no aeronautical training, no pilot training, no experience with airline operations, and no business experience.

You can also google my experience. I have a degree in mechanical engineering with a minor in aeronautics from Caltech. I worked for Boeing for 3 years on the 757 stabilizer trim design. (It is not identical to the 737 stab trim design, but is close enough for me to understand it.) At one point I knew everything there was to know about the 757 trim system. A couple dozen feet away was the cockpit design group, and we had many very interesting discussions about cockpit user interface design.

I'm not a pilot myself, but other engineers at Boeing were, and they'd take me up flying for fun. Naturally, airplanes were all we talked about. My brother and cousin are pilots, my cousin was a lifer engineer at Boeing, my dad flew for the AF for decades in all kinds of aircraft, with an engineering degree from MIT. I inherited his aviation library of about a thousand books :-/ Naturally, airplanes were a constant topic in our family.

I've talked with two working 737 pilots about the MAX crashes.

I've read the official government documents on the MAX crashes, and the Emergency Airworthiness Directive.

That's what I "hang my hat" on. So go ahead, tell me I don't know what I'm talking about. But before you do, please look up the credentials of the journalists you're getting your information from.

P.S. "Aviation Week" magazine has done some decent reporting.

P.P.S. Amazingly, the "Aviation Disasters" TV documentary is fairly decent in its analysis of various accidents, lacking the histrionics of other treatments. But it's rather shallow, considering it's a 40 minute show.