Incident: American B38M near Nassau on Mar 29th 2021, pitch trim issue/failure

I have no opinion about flying on this particular plane.

It's not so much MCAS, electric trim, this, or that.

The bigger issue is it's too complicated, has too many features, and the FAA can't adequately oversee testing and certification all the way down the engineering stack. Furthermore, because of pressures to save a buck, Boeing is willing to cut corners and sacrifice safety by slapping a plane together without properly engineering or testing it. Because of this behavior, it's difficult to know how many other problems are lurking around like in the 787.

I respectfully disagree. A news article calling them flaws does not make them a flaw. Here's the issue: At lower speeds such as you'd see during a landing approach, the throttle setting of the 737 Max directly affects its pitch. If the pilot were to suddenly reduce throttle, the nose would pitch up. This is due to the engine's more forward position.

The forward position of the engines was done so that they wouldn't have to re-engineer half the plane to fit the larger engines. High bypass turbo fans are big, and they couldn't maintain ground clearance without either moving the engines up higher or making the landing gear longer. To move the engines higher they had to move them forward. So they did.

The new behavior of the aircraft required retraining and making sure pilots knew how the throttle and pitch were related. Mind you, a lot of aircraft have such relationships, so this is not in itself a flaw.

The real flaw came when they decided to replace training with software, and then conveniently forgot to tell anybody about the robo-pilot that they put in the cockpit. THAT was the failure. The airplane itself, even without MCAS at all, would be a bit more of a handful to fly, but nothing terrible. With a properly functioning MCAS, and proper training about how to disable it in case of a problem, the issue is solved. And that's what the FAA believed happened when they recertified the 737 MAX to fly again. But by now the reputation has been tarnished so badly that we're hearing news about unrelated failures because it happened on a 737 MAX.

So you can see the real failure isn't aerodynamic, its pretty much everything else.

If I got any details wrong, I apologize. I'm flying by the seat of my pants on this layman's analysis after a long day.

But this doesn't feed the machine that is the 24-hour news cycle. I fully expect cable news to try to declare "more trouble for troubled plane," even though it appears to be a garden variety failure.

>At lower speeds such as you'd see during a landing a approach, the throttle setting of the 737 Max directly affects its pitch.

Any conventional airliner has this "flaw". If you are at low airspeed and you push the throttles forward, an A320 will exhibit nose-up pitch, too. It's a direct consequence of having giant engines slung kinda-sorta-underneath the wings of a low-wing monoplane.

So I actually went and found this fabled 245-page report :

https://transportation.house.gov/imo/media/doc/2020.09.15%20...

And this, I think, is where the whole faulty/flawed thing gets introduced :

> Faulty Design and Performance Assumptions.

> Boeing made fundamentally faulty assumptions about critical technologies on the 737 MAX, most notably with MCAS. Based on these faulty assumptions, Boeing permitted MCAS—software designed to automatically[...] It also expected that pilots, who were largely unaware that the system existed, would be able to mitigate any potential malfunction. Boeing also failed to classify MCAS as a safety-critical system, which would have attracted greater FAA scrutiny during the certification process.[...]

So, I would agree that Boeing's design flaw here was not alerting the pilot with a huge red warning light (and being cheeky about re-certification). But I don't think that this report goes so far as to say that the airframe was flawed and therefore necessitated MCAS.