https://www.google.com/url?sa=i&source=web&cd=&ved=2ahUKEwj027zOy4XhAhUHEawKHVCNDMoQzPwBegQIARAC&url=https://www.nytimes.com/2019/03/15/business/boeing-ethiopian-crash.html&psig=AOvVaw3Erl7Ezfc8mJREbz3qRh_m&ust=1552788914351914 So earlier today I was speaking to 2 people--an aeronautical engineer who works for a defense contractor on jet aircraft, and a computer science engineer with a degree from Georgia Tech. Both of them are private pilots although one of them only works professionally in the aerospace industry. I asked them about these two crashes involving the Boeing 737 max-8. They theorized that the airplanes' automatic pilot system caused it. These systems now appearing in passenger jets incorporate a computer override that will prevent the pilot from assuming manual control if the computer decides that the pilots movements (stick, rudder, throttle, etc.) are inconsistent with the safe operation of the airplane. In other words, the primary flight responsibility is the computer (auto pilot) but when everything is going well the human pilot has the option of disengaging the auto pilot and flying the plane manually (although it is still fly by wire, with all the control levers & buttons connected to a circuit board which treats them as requests, and only if the computer approves the request will pistons actuate and servos move, which causes the airplane to actually turn or otherwise change what it's doing.) But if the computer thinks that the airplane is climbing too steeply, it will automatically increase the throttle (to prevent a stall) and push the nose down in an attempt to come back to level flight. If the sensors were in error and the computer is working on false data, this will cause the aircraft to fly at full throttle straight down into the ground and make a big smoking hole. While the pilots will see this coming and might realize what's about to happen, there's not a got-damned thing they can do about it. Because the computer has priority over the human pilots now.