And the nitty gritty on the AD last page
Figure 1 to paragraph (g) of this AD — Certificate Limitations
Required by AD 2018-23-51
Runaway Stabilizer
In the event of an uncommanded horizontal stabilizer trim movement,
combined with any of the following potential effects or indications
resulting from an erroneous Angle of Attack (AOA) input, the flight crew
must comply with the Runaway Stabilizer procedure in the Operating
Procedures chapter of this manual:
• Continuous or intermittent stick shaker on the affected side only.
• Minimum speed bar (red and black) on the affected side only.
• Increasing nose down control forces.
• IAS DISAGREE alert.
• ALT DISAGREE alert.
• AOA DISAGREE alert (if the option is installed).
• FEEL DIFF PRESS light
• Autopilot may disengage.
• Inability to engage autopilot.
(h) AFM Revision: Operating Procedures(h) AFM Revision: Operating Procedures
Within 3 days after the Within 3 days after the effectiveeffective date of this AD, revise the date of this AD, revise the Operating Operating Procedures chapter of the Procedures chapter of the
applicable AFM to include theapplicable AFM to include the information in figure information in figure 2 to paragraph (h) of this AD. 2 to paragraph (h) of this AD.
So why is the AOA DISAGREE AN OPTION ???