B737MAX LAND 2/3

[_Viking_]

Hello guys and gals,

I am trying to obtain an understanding of the logic behind the annunciation of either LAND 3 or LAND 2 on the Autopilot status display during a dual channel approach. More specifically, which items the aircraft monitors itself and would, if inoperative, render a downgrade from LAND 3 to LAND 2.

The FCOM does not cover this.

The AFM has the following list of items required to be operative with LAND 3/2 displayed.

Fail-Operational
The autopilot system has been shown to meet the applicable airworthiness performance and integrity criteria established by CS AWO Subparts 1 and 3 for an automatic landing system with the following functions operative and LAND 3 annunciated:
Two engine operation at flaps 30 or 40
Autoland status annunciation on both Displays
Autothrottle at the start of final approach
Approach Minima Display for each Pilot or no minima for no DH operation
Windshield Wipers for each Pilot
Flight Mode Annunciator for each Pilot
Normal flight controls
Anti-skid brake system

Fail-Passive
The autopilot system has been shown to meet the applicable airworthiness performance and integrity criteria established by CS-AWO Subparts 1 and 3 for an automatic landing system with the following functions operative and LAND 2 annunciated:
One engine operation at flaps 30 or two engine operation at flaps 30 or 40
Autoland status annunciation on both Displays
Approach Minima Display for each Pilot
Windshield Wipers for each Pilot
Flight Mode Annunciator for each Pilot
Normal flight controls

The autopilot is of course not monitoring all these items requiring the flight crew to assess the status of the aircraft prior to approach.
My question is really; What is the autopilot/AFDS monitoring that would cause it to downgrade itself from LAND 3 to LAND 2 (or NO AUTOLAND for that matter).

Hope that all makes sense.