system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: the Boeing 737 Max uses a computer to 'fly against nature'. What does this mean?

I heard a pilot talk about this today: "It shouldn't be able to fly, but there is a computer constantly making adjustments to power and trim to keep it flying." How is this achieved and wouldn't it be easier to stick with what we know?
gpt
I suspect the pilot attributed more to the changes in the new design then it could be attributed with. The 737 Max have limited changes from previous 737s and is mostly performance items from the 787 development. The flight computers and cockpit are the same as previous models and the airplane have most of its major design elements from 1966.

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But there is such a thing as he describes. It was developed for fighter airplanes. One of the fundamental principles of stable flight is that the center of mass have to be in front of the center of drag/lift. The most extreme example is a dart. If you throw a dart backwards it will flip around so the heavy pointy end faces front even as you release it. And a similar thing happens for aircraft as well. This is why the classical stable aircraft design is to have a heavy engine in the front and a long light tail with fins on it. The aircraft will naturally fly the way you are pointing it. However for fighter airplanes this is a problem as they often want to go a diferent direction and therefore want the front to face a different way. So starting with the F-16 the new fighter design have the center of mass moved far enough behind so the aircraft is unstable. The aerodynamic forces on the aircraft will always want to turn the aircraft around. And pilots are not fast enough to react when this happens which is why you need flight computers to do the actual flying.

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That being said the modern airplanes also have very similar flight computers and will constantly adjust different things like power and trim. However this is done for fuel economy and comfort more then being a requirement for stable flight. Pilots can and regularly do turn these features off for various reasons. For example when they are diagnosing an issue, certain items are not working or they need the training.