Re: ... the FAA's statutory mandate to "promote" the aviation industry
I know next to nothing about how to build a jet engine and a jet airplane. Yet I also like Mr. Feynman, who knew nothing about Space-shuttle Challenger, yet he figured out how it happened and why. From folding paper airplanes and letting them fly, both into the wind and against the wind, I know just a wee bit about airworthiness. With that knowledge, I'll say:
It's about BALANCE. In theory and in practice, you want a plane that "sits in the air comfortably". Anytime a plane either is too heavy at the front, or in the back, you got a problem with BALANCE. Kindly use your imagination, and keep your sense of humor handy as well.
With paper planes, it's easy to counteract a paper plane's tendency to fly up too steeply into the air, (especially against the wind) and to enter a stall condition, making it dive deeply, only to go up steeply again. That results in an "upsy, downsy, upsy, downsy" flight path, which can be fixed either by a counterweight (a paper clip, generally) at the nose, or by "ripping some wing-flaps (aka elevators) into the back-wings" and to adjust these "elevators on the back wing slightly downward" (via trial and error), to make the flight path smooth, easygoing, long-lasting and super-cool.
With jet planes, a gigantic paper clip attached to a B 737 Max to the nose, or thereabouts, is generally out of the question. Neither Office Depot, Office Max, or anyone carry such sufficiently gigantic paper clips, and even if they did, the result would be a type of "doo-hicky, duct-tape like" solution that does not inspire the desired confidence in the flying public. Thus, we can disregard the paper-clip solution from the start.
Clearly, Boeing tried to produce a solution that involved the elevators on the back wing, and a type of air-flow measuring device in the front, (which in essence functions like a weather vane or wind vane), that is electronically transmitting input to the flight computer. MCAS then tries to put together the info about speed, angle of the plane, stalling limits, and the level of change in how fast it's moving upwards or downwards, and provides automated output, leading to automated corrective action. Fair enough.
But then again, in practice, if the plane is flying in a type of weather, such as when either hot air over a desert, or humid hot air over an ocean, or a T-storm, is rising rapidly, would the weather vane input show false info, simply by being pushed slightly upward? I'd say that's a consideration. Has that been considered? Just wondering! Testing in Washington State, but then flying over Sahara or over tropical seas? Think!
Likewise, the elevator flaps in the back wings are really important to any pilot, because they make the plane either move up, or move down, or stay level. If I were a pilot, and some flight computer suddenly overrules my ability to maneuver the plane, I'd be more than slightly concerned, especially if Boeing, as it turned out, did not even inform me about this possibility. I am not accusing Boeing of wrong-doing, I am just reporting ideas.
Sure, is man always right? No! Is the computer always right? No again! Man vs machine, an age old problem. Lot's of variables to consider, such as balance, fuel use, profitability, etc.
Next, has Boeing considered refining the way the input from the weather vane indicators is handled? This type of input appears to be subject to more random moves by the elements, weather, etc. Updrafts, downdrafts, water, rain, ice, storms, etc... how are these factors weighing in on how the raw data is being used?
Has Boeing considered actual counterweights to the forward position of the new more efficient jet engines? Yup, weight costs money, but sometimes a small change makes a big diff.
Also, could the position of the thrust reversers be changed, such that only one part, one half of them, could be used to provide slight upward thrust as a corrective action, (as opposed to MCAS interfering with the elevators in the back wings). I think that the thrust reversers currently are used only horizontally, providing breaking action to the forward left and to the forward right upon landing, with each half of them fully deployed. A 45 degree rotation of the reverse thrust "thingies", and revamping, so that they could independently provide a bit of either upward or downward thrust could be a solution to that MCAS dilemma. Can you imagine what I say here?
Cost? I don't know! Come on, I started with paper airplanes, how should I know cost accounting? That's your job.
Sure, for the military, nothing appears to be too expensive to try, while for the commercial market nothing appears to be too cheap to try. How about some balance between the two? Really now, Boeing, can't you use some of your military profits to make your commercial planes a wee bit safer? Give yourself a push and do it. Without imagination, you got nothing.