B-18 Page 2 of 22
MN-FLT-OH-201
Flight Crew Operations Manual Bulletin No. GOT-18 , Dated March 1, 2021 (continued)
Background Information (continued)
New FCC software, P12.1.2, is being introduced which includes enhancements to
the Speed Trim System and more specifically the MCAS function. The new FCC
software reduces opportunities for erroneous MCAS activation and reduces the
maximum MCAS stabilizer trim authority. In addition, FCC software P12.1.2
introduces updates to the Autopilot Flight Director System. These updates
include changes to autopilot nose up stabilizer trim (flaps extended only),
automatic autopilot disengagement and flight director guidance when stick
shaker activates (only for AFDS modes that do not have minimum speed
reversion).
This bulletin is being issued to easily identify the updated information and is
organized in the same format as the FCOM. All of these descriptions are also
incorporated in this FCOM revision. The SPEED TRIM FAIL and STABILIZER
OUT OF TRIM Non-Normal Checklists have been revised as a direct result of
the introduction of FCC P12.1.2. In addition, five other Non-Normal Checklists
have also been revised. All of these Non-Normal Checklists are also included in
this FCOM revision and outlined in this bulletin for easy reference. In addition,
the QRH-CI have been updated to provide flight crew guidance for management
of non-normal situations.
All deliveries of 737-7/-8/-8200/-9 airplanes after the issue date of this bulletin
will include the new FCC P12.1.2 software. For 737-8/-9 airplanes not delivered
with FCC P12.1.2, Service Bulletin 737-22A1342 will be made available to
provide FCC P12.1.2 software installation instructions.
March 1, 2021