blackwater wrote:

CNet covers it here.

What are the investigations focusing on?

Remember those larger CFM LEAP engines? Well, because they're bigger, and because the 737 sits so low to the ground (a deliberate design choice to let it serve small airports with limited ground equipment), Boeing moved the engines slightly forward and raised them higher on their underwing pylons. (If you place an engine too close to ground, it can suck in debris while the plane is taxiing.)

That new position changed the aircraft's center of gravity, creating the potential for the nose to pitch up during flight. Boeing designed software called the Maneuvering Characteristics Augmentation System, or MCAS, to overcome this action. When a sensor on the fuselage detects that the nose is too high, which could eventually cause the plane to stall, MCAS automatically pushes the nose down.

Investigators in the Lion Air crash have said that a fault in the the sensor may have been feeding incorrect data to MCAS, pitching the nose down into a dive. According to the investigation, the Lion Air pilots struggled to take control of the plane before the crash as it pitched up and down. (For a thorough explanation of MCAS, see this story from The Air Current.)

So basically, Boeing designed a complex computer system to compensate for an instability in the plane. The complex computer system appears to have malfunctioned.

Granted, once you express it with Trump's vocabulary, it sounds like your grandma complaining about the webs being down again. But he's not completely wrong in this case.

Of course, we don't completely know what's going on, since the investigations aren't complete. It's possible that the investigations will turn up something different as the root cause of the crashes. So you could argue that Trump should let the experts at the FAA do their job. But that's a different argument than just saying he's completely crazy.