I don't know why you are being downvoted, because you are right. While software and sensors to account for unstable airframes is not uncommon in aviation, before the 737 MAX, there has never been a civilian passenger plane with such a dynamically unstable frame requiring real-time correction via software and sensor data. In civilian aircraft, unstable frames like what we saw in the 737 MAX were not a thing. And honestly, I don't want them to become a thing either.

I also acknowledge that the specific terms I use in this comment might not be 100% down to the letter terms used in the aviation industry (such as unstable frame). The point being made here is corners were cut, Boeing is 100% to blame for the situation they find themselves in with the 737 MAX.

In avionics, fighter jets are unstable requiring computers and algorithms to keep them flying. This is in part to the speed of which they travel, the [Dassault Rafale](https://en.m.wikipedia.org/wiki/Dassault_Rafale) has multiple levels of redundancy to correct negative flight conditions (it has three computers I believe).

Even with the fixes, the plane is still going to be unstable. However, fortunately, unstable planes like passenger jets which move slower can still be manually flown (unlike fighter jets moving at Mach 1). But, I am definitely not going to fly on a 737 MAX if I can avoid it, not until it has proven itself in service for 10 years. I wouldn't say fixing an engineering problem with the software and additional sensors inspires confidence.

Dynamically unstable airframes should not be a thing in passenger jets. The only reason the 737 MAX is unstable is that they put bigger engines on a 737 and moved them up because of how low the 737 sits on the ground, thus disrupting the centre of gravity and requiring pitch correction when at full thrust.

The Airbus A320 has no such issues with its design. It can safely glide during total engine loss for quite a long distance. Could the 737 MAX claim the same thing?

At full thrust the nose would point too far upward with the new design, potentially causing a stall. MCAS automatically pushed the nose down if the nose was detected to be pointing too far up. Pilots received a two-hour training course on an iPad before being allowed to fly on the 737 MAX, they didn't even highlight the new MCAS system. The training material didn't even mention the new MCAS software...

The worrying thing about this entire situation is the MCAS system relied on a single AOA (Angle of Attack) sensor and overreacted and took control of the plane. Given planes are known for their levels of redundancy, a single sensor and some overzealous software coupled with other mistakes resulted in hundreds of lives lost. Pilots were not even notified in the cockpit that the MCAS software had taken over control of the plane. How insane is that?

This all happened because Boeing pretended the 737 MAX was basically the same as the 737. The cause of the problems was not because of poor software, it was because Boeing tried to cut costs and put in a bandaid solution for the unstable frame they created. The software did its job, it's the lack of redundancy and ability to manually override the system that was the problem. They're just doubling down on it because there is no alternative to the engineering problem they created.

MCAS = May Crash Any Second