[Stierlitz]

Will the pilot be able to override MCAS at take-off or landing?

“Summary of the FAA’s Review of the Boeing 737 MAX”

https://www.faa.gov/foia/electronic_reading_room/boeing_read...

“The 737 MAX was designed to handle and feel the same to the pilot as the 737 NG. Without the MCAS function, in some small areas of the flight envelope — such as approaching a stall and during higher g-force maneuvering — the new engines contribute to the control column feeling lighter in the 737 MAX than the regulations allow.”

The Flight envelope is unstable without MCAS.

“MCAS provides signals to move the horizontal stabilizer at elevated angles of attack to compensate for the aerodynamic effects of the 737 MAX’s larger and more forward-located engines, resulting in the required column feel to the pilot.”

The plane pitches nose-up under high acceleration.

[jacquesm]

> The Flight envelope is unstable without MCAS.

You do not understand the use of the word 'stable' in relation to the words 'flight envelope'.

737 Max is stable across all of its flight envelope.

The worst you could accuse it of is that at one extreme of the flight envelope it gets close to neutral, but it never is unstable.

[kayfox]

Heres a graph that circulated that gives you an idea of what the forces are (please note the graph is not an actual graph, but based on the characteristics as described):

https://www.eng-tips.com/viewthread.cfm?qid=457125#:~:text=T...

Note that the resistance does not start dropping until after the stall. Also note what MCAS does with the forces.

[tzs]

> Will the pilot be able to override MCAS at take-off or landing?

The pre-fix MCAS has not enabled when flaps were down, which covers a large part of takeoff and landing. I think there was also a minimum altitude for it to be enabled.

I don't know if any of this changed with the new version.

[crznp]

> Either pilot can override MCAS commands to control the stabilizer by using the electric stabilizer trim switches on the control wheel. Additionally, flightcrews can set the STAB TRIM CUTOUT switches on the center control stand to CUTOUT to stop and disable MCAS.

So pilots would be able to override MCAS (and they could before, though it was less explicit). They can't routinely override it at take-off or landing because 737 MAX without MCAS is non-compliant and:

> when MCAS and Speed Trim are disabled, SPEED TRIM FAIL is annunciated and a maintenance item is recorded.

e: Also, there were changes for when/how MCAS is in effect