“The implementation of MCAS with its lack of redundancy, lack of sensor failure detection, and a poorly executed last minute increase in MCAS scope and trim authority have been the disaster.”
There’s a Youtube video of a reenactment of one of the crashes. The plane hit the ground almost vertical. The pilot turned MCAS on and off. How could plane’s control system point the plane almost vertical into the ground? How could it prevent the pilots from manually leveling the plane?
After the first fatal crash, Boeing issued this airworthiness directive that outlined exactly what MCAS did, how it can runaway due to a faulty flight attitude sensor, and how to disable MCAS.
The Lion Air crash was perhaps understandable, but the Ethiopian Airlines crash happened two months after the directive was issued, and the pilots should have been well aware of the potential issue and exactly how to quickly and correctly respond to it.
The problem was that in the implementation of MCAS that ultilmately found its way into the MAX, MCAS would repeatedly input down trim to the horizontal stabilizer until the trim limit was reached. That would make it very difficult to pull the aircraft back up at very high speeds. But the pilots would know that repeated uncommanded down trim was being applied, as a large horizontal trim wheel near the pilot's knee would be moving very rapidly with a loud whirring motor noise.
I'm not sure which YouTube video you saw, but here's one by 737 instructor pilot Mentour who demonstrates what MCAS runaway trim looks like in a simulator, and how to correct it:
There’s a Youtube video of a reenactment of one of the crashes. The plane hit the ground almost vertical. The pilot turned MCAS on and off. How could plane’s control system point the plane almost vertical into the ground? How could it prevent the pilots from manually leveling the plane?
The two crews that flew these planes into the ground were not competent to be even flying not alone a sophisticated Air Vehicle.. These two crews that were flying the 737 max 8 would have killed everybody on board Capt Sully’s Chesley Burnett Sullenberger aircraft that hit the flock of birds. He landed his plane in the Hudson river successfully. If he would have listened to the Air traffic Control after he called a mayday he would have killed everyone on board.