Got that a bunch of planes crashed, which is horrible. But what was the problem exactly -- why did the planes crash? Who caused it?
Incompetent pilots (not trained to use the new tech) crashed the plane and people now blame Boeing because certain packages available on more expensive versions could have prevented the problem. I know - This is an unpopular opinion.
Terrible design. Lack of extensive testing. Not letting the pilots know the changes to their softwares. Basically tried to undercut to push a new plane out in the market.
Boeing designed a system to fix an issue where the plane would pitch too far up, however that system relied on a sensor with a single point of failure. That single point of failure combined with a lack of required instruction on the new system lead to pilots being unable to override a fail-deadly system
This sounds like a good high level summary.
Closest explanation so far. It’s important to go into more details. Boeing is trying to compete in better fuel efficiency with airbus. New engines would give that but problem was they couldn’t mount them in a proper position on the wing because of the size. So they mounted them more forward to raise the height instead of redesigning the 737. Then thought they could add a fly by wire system to compensate for the instability. That led to the issue original commenter posted above.
No. I’ve heard the explanation from parties directly involved. It’s impossible to summarize without knowing the details
Vox video with good explanation: https://youtu.be/H2tuKiiznsY
Airbus launched the A320neo which was more fuel efficient and could be flown by pilots with existing A320 certification. Boeing needed to keep up, so they retrofitted the 737 with more fuel efficient engines. However these were bigger and sat more forward, so the plane was more prone to stalling. To counteract that, Boeing added a new system (MCAS), but in order to not require expensive pilot re-training, they didn't document it. It also relied on a single data source. When that single source fails, the system thinks the plane is stalling and points the nose to the ground. Pilots can correct the trim manually with a wheel, but it's exhausting to turn, and MCAS reengages within minutes and pilots have to do the same thing again, until they're exhausted and the plane crashes. Since they're not trained on MCAS, they don't know how to disable it.
Two planes went down, what else you want me to explain?
“I would if I were in such a position. What we had in the two downed airplanes was a textbook failure of airmanship. In broad daylight, these pilots couldn’t decipher a variant of a simple runaway trim, and they ended up flying too fast at low altitude, neglecting to throttle back and leading their passengers over an aerodynamic edge into oblivion. They were the deciding factor here — not the MCAS, not the Max.” http://www.nytimes.com/2019/09/18/magazine/boeing-737-max-crashes.amp.html
If Boeing is not at fault, why planes been grounded for long time?
Because it's a combination of poor design and poor training. Boeing needs to a fix for both or idiot proof it. A simpler but relatable problem was when Toyota had a floor mat issue. When morons would work there floor mats up under the petals to the point they couldn't control the vehicle. It's easier to design a fix (floor mat clips) than to train the average idiot to not to jam the floor mats up under the petals. So Boeing needs to engineer a fix and get FAA approval by showing test results. Some additional training documents will likely be available. It's up to the pilots if they want to read and understand such documents.
Foreign pilots are undertrained and couldn’t deal with simple problems US pilots easily overcame. Part Boeing hubris regarding pilot training, part inadequate training on the part of non-US pilots. Boeing will rebound and be fine.
It was a big in auto-pilot software called as MCAS. It seems Boeing did not do enough testing and cut corners and lobbied to get it approved by FAA.
MCAS is not autopilot. It even gets turned off when autopilot is on