MN-FLT-OH-201
B-10 Page 3 of 8
Flight Crew Operations Manual Bulletin No. GOT-10 , Dated August 20, 2018 (continued)
• Change in ADIRU position (Figure 8)
• SPEEDBRAKE Warning (aural and visual) can alert, if this option is
installed (figure 9)
Note:
These flight deck effects happen post-flight only and are not always
present. It depends on how much IRS drift error has occurred during
flight (i.e. the difference between IRS position and GPS position) and
whether the airplane remains motionless long enough for post-flight
ANR mode to complete before IRS mode selectors are set to OFF or a
full alignment or Fast Realignment is done. If the difference is small
(approximately 1 nm), the FMC position, track, and ground speed
transient errors may not be noticeable.
The flight deck effects described above will last approximately 10 - 120 seconds,
depending on the IRS position update magnitude, after which the ND and PFD
will return to normal and the visual SPEEDBRAKE Warning (if installed) will
extinguish. Heading on the PFD and ND is not affected.
It is important to note that the flight deck effects described in the above are only
possible when the post-flight ANR mode is active after completion of a flight and
valid GPS position is received, i.e., cannot occur during taxi out even if the
airplane remains stationary for approximately 7.5 to 15 minutes. Also, if the
airplane is moved (motion detected) prior to the ANR mode completing the
realignment, the ANR mode is stopped, I-ADIRU position drift errors remain and
none of the flight deck effects described above are presented to the flight crew.
The ANR mode timer is restarted from the beginning when the airplane again
remains stationary (motionless).
The following is more specific information on 737 MAX models affected by this
bulletin:
• 737-7 – All
• 737-8
•Line number 6854 and earlier if Service Bulletin 737-34-3141 is
incorporated
•All from line number 6855 and on
• 737-9 – All
March 1, 2021