I am not sure that I would label myself a Boeing fan boy. I have been a licensed pilot for over 30 years and had flown hang gliders and ultralight aircraft for ten years before that. But my interests have been in general aviation, homebuilt experimental aircraft, ultalight aircraft, hang gliders and flight simulators. I have heard various explanations about what would have needed to be done when the two Boeing 737 MAX aircraft malfunctioned and crashed.
There is no question in my mind that Boeing screwed up in various ways. However, the reporting on this was horribly botched and I am not sure that the explanation that you gave though repeated often, is completely accurate. It is not completely accurate according to people that I know who fly the aircraft. I have no firsthand personal experience... do you?
No I have no firsthand knowledge and I am not a pilot.
What particular part of my post(s) do you take exception?
MCAS is part of the Flight Control Computers, not an actual separate system. My understanding is there are two FCC’s and they each have their own AOA sensor. Only one FCC is in command at a time. The MCAS function also uses the same trim motor as what is used by the auto pilot function and the manual electric trim switches.
In other words, you cannot deactivate the MCAS without deactivating electric trim. Maybe I am incorrect, but I don’t think there was a way to turn off the MCAS flight laws.
I’ve read that the MCAS would resume trimming the nose down after a five second pause if the AOA sensor was still showing an unacceptable upangle. I’ve read that this will now only occur once. I’ve also read that the MCAS laws have now been limited to how many degrees it can move the horizontal stabilizer.
So those are two changes Boeing has made. Limit stabilizer movement and limit it to one correction. The most significant change I’ve read about is that the MCAS will now not initiate if there is a disagreement of ten degrees or more between the left and right AOA sensors.
I could be wrong, but I believe only the higher cost display option offered (where the actual AOA readings were shown in the displays and had a disagreement alarm) disabled the MCAS - but I am not sure if that was the case. Maybe the higher cost option did not disable MCAS after a disagreement. But the two aircraft involved in the crashes did not have AOA displays or disagreement alarms, and the MCAS feature relied on only one AOA sensor.
Now MCAS is disabled on all 737 MAX jets if the left and right AOA sensors disagree by ten degrees or more whether or not the AOA display and disagreement alarm feature is ordered.
Your 737 friends… how are they describing the failure? Are they blaming poorly trained pilots? Do they dispute anything I’ve said about the MCAS? I agree that better trained and more experienced pilots would have been able to save the planes. In fact, the crew who flew the second doomed plane immediately prior to the accident flight did experience runaway trim from the MCAS and recovered the plane. The crew who took over for the next flight were obviously not able to recover. Regardless, I place the blame on Boeing’s design. A single sensor failure would make the plane drive itself into the ground.