This is an insane take. The plane was fitted with an undocumented automatic system that would erroneously change the pitch about ten times faster than what the pilot switches allowed, and that would automatically re-engage repeteadly as soon as the pilot released their switch, negating all progress made by the pilot. It would continue this adjustment blindly despite copious information available to the flight computers that a crash with terrain is imminent and that the pilot is having trouble leveling the plane.
So the electronic control route was fried, any normal person in that situation and physical and mental overload would conclude that trim controls are not functional.
The manual route, which they tried, involved at that speed an undocumented "roller coaster maneuver", pitching forward (!!) to release pressure on the trim mechanism and allow manual adjustment. It goes without question it's impossible the pilots could have come up with that solution in the mere seconds they had at their disposal, let alone the high risk it entailed.
Reducing the throttle early would have saved the plane, but it would have also resulted in immediate pitch down due to the torque the engines create against the body of the plane, as they are mounted off axis. The autothrottle was left to near 95% for the entire ~250s duration of the flight (the setting necessary for take off at the particular altitude of the airport) and once the cascading failures consumed all their situational awareness it stands to reason why they failed to adjust it and then hesitated to perform an action that would have (in the short run) worsened the problem in a near crash situation.
The MCAS as designed was a ticking timebomb that killed two plane loads of people in mere months, and Boeing accepted full responsibility for that, even if they are still denying criminal charges.
The 737 has had the issue of runaway trim forever. The giant "wagon wheels" used for trimming early models were very loud when activated, and part of that was to give the pilots a heads up that something unexpected was happening.
> about ten times faster than what the pilot switches allowed
This is utterly false. The trim rate has two speeds - on and off.
> would automatically re-engage repeteadly
This is called "runaway trim". The procedure to counter it is to turn it off. The same procedure for every airplane.
> any normal person
Pilots are required to read and understand and remember Emergency Airworthiness Directives.
Don't forget the first MCAS incident, where normal trim was restored with the column trim switches and then the trim was turned off and the airplane landed safely.
Or the second where normal trim was restored 25 times, but never turned off.
I would expect a MAX pilot to have paid attention to that crash, and the followup EAD which instructs them to restore normal trim with the column switches and then turn it off.
> This is utterly false. The trim rate has two speeds - on and off.
This is wrong and easy to disprove. The trim rate for a pilot issued trim command starts at 0.4 degrees/second at low air speeds and tappers off to zero as the speed increased towards Mach 0.68. The MCAS had a fixed rate of 0.27 degree/second that did not depend on airspeed. Here is the relevant quote from the FAA report on the 737MAX:
> “If activated by a high AOA, MCAS moves the horizontal stabilizer at a rate of 0.27 degrees per second, which is the same trim rate as Speed Trim with flaps down. The magnitude of the MCAS command is a function of Mach and angle of attack. At higher airspeeds, flight‐control surfaces are more effective than at lower airspeeds. Therefore, a smaller MCAS command at higher airspeeds has the same effect as a larger MCAS command at lower speeds."
So the trim rate is fixed but the magnitude (duration) of the original MCAS is variable to account for airspeed. Because the MCAS reengaged repeatedly due to erroneous AOA sensor data and faulty design logic, the duration became irrelevant. However, as the plane speed exceeded 0.6 Mach, the rate of pilot trim substantially decreased, meaning that a full 10s second activation of the MCAS could no longer be negated by a 10s trim command from the pilot. The flight recorder shows trim commands of up to 4 seconds, which in fact allowed the MCAS to re-engage and issue a fresh 10s opposite command, at a higher rate. This is a disastrous succession of events that can't be blamed on the pilot.
I won't go down the rabbit hole with the rest of your comment, enough to say you need to better vet your sources and reevaluate your claims. The Ethiopian Airlines pilots fought for their lives for a few desperate minutes and lost, quite possibly made some mistakes but overall many other qualified pilots would have failed too in the same scenario.
If you look at a wiring diagram of the switches, the column trim switches turn the trim on/off. The pilot can leave it on for a long or a short duration, but the trim rate remains the same.
The trim motor that drives the jackscrew is not a variable speed motor. It is only on or off.
The trim duration is not the same as the trim rate. Analogously, velocity and time are not the same thing.
You have misunderstood the FAA report.
> you need to better vet your sources and reevaluate your claims
Again, the MCAS trim rate is fixed to a relatively high value, that's what the FAA report talks about. The rate of a pilot issued command is variable, affected by the flaps setting and airspeed. This is very easy to confirm. You can see an experienced 737 pilot explain this at the link above, around the 40 minutes mark.
So the electronic control route was fried, any normal person in that situation and physical and mental overload would conclude that trim controls are not functional.
The manual route, which they tried, involved at that speed an undocumented "roller coaster maneuver", pitching forward (!!) to release pressure on the trim mechanism and allow manual adjustment. It goes without question it's impossible the pilots could have come up with that solution in the mere seconds they had at their disposal, let alone the high risk it entailed.
Reducing the throttle early would have saved the plane, but it would have also resulted in immediate pitch down due to the torque the engines create against the body of the plane, as they are mounted off axis. The autothrottle was left to near 95% for the entire ~250s duration of the flight (the setting necessary for take off at the particular altitude of the airport) and once the cascading failures consumed all their situational awareness it stands to reason why they failed to adjust it and then hesitated to perform an action that would have (in the short run) worsened the problem in a near crash situation.
The MCAS as designed was a ticking timebomb that killed two plane loads of people in mere months, and Boeing accepted full responsibility for that, even if they are still denying criminal charges.