Бабушки у подъезда:
- а ты слышала что Медведев завёл блох в свитере?

Flight Crew Operations Manual Bulletin
for
The Boeing Company

Number: TBC-19
IssueDate: November 6, 2018
Airplane Effectivity: 737-8 / -9
Subject: Uncommanded Nose Down Stabilizer Trim Due to Erroneous Angle of
Attack (AOA) During Manual Flight Only
Reason: To Emphasize the Procedures Provided in the Runaway Stabilizer Non-
Normal Checklist (NNC).
THE FOLLOWING PROCEDURE AND/OR INFORMATION IS EFFECTIVE UPON RECEIPT
Background Information
The Indonesian National Transportation Safety Committee has indicated that
Lion Air flight 610 experienced erroneous AOA data. Boeing would like to call
attention to an AOA failure condition that can occur during manual flight only.
This bulletin directs flight crews to existing procedures to address this condition.
In the event of erroneous AOA data, the pitch trim system can trim the stabilizer
nose down in increments lasting up to 10 seconds. The nose down stabilizer trim
movement can be stopped and reversed with the use of the electric stabilizer trim
switches but may restart 5 seconds after the electric stabilizer trim switches are
released. Repetitive cycles of uncommanded nose down stabilizer continue to
occur unless the stabilizer trim system is deactivated through use of both STAB
TRIM CUTOUT switches in accordance with the existing procedures in the
Runaway Stabilizer NNC. It is possible for the stabilizer to reach the nose down
limit unless the system inputs are counteracted completely by pilot trim inputs
and both STAB TRIM CUTOUT switches are moved to CUTOUT.
The Boeing Company
Seattle, Washington 98124-2207
Information in this bulletin is recommended by The Boeing Company, but may not be FAA approved
at the time of writing. In the event of conflict with the FAA approved Airplane Flight Manual
(AFM), the AFM shall supersede. The Boeing Company regards the information or procedures
described herein as having a direct or indirect bearing on the safe operation of this model airplane.

Additionally, pilots are reminded that an erroneous AOA can cause some or all of
the following indications and effects:
• 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.
• Inability to engage autopilot.
• Automatic disengagement of autopilot.
• IAS DISAGREE alert.
• ALT DISAGREE alert.
• AOA DISAGREE alert (if the AOA indicator option is installed)
• FEEL DIFF PRESS light.
Operating Instructions
In the event an uncommanded nose down stabilizer trim is experienced on the
737-8 /-9, in conjunction with one or more of the above indications or effects, do
the Runaway Stabilizer NNC ensuring that the STAB TRIM CUTOUT switches
are set to CUTOUT and stay in the CUTOUT position for the remainder of the
flight.
Note: Initially, higher control forces may be needed to overcome any
stabilizer nose down trim already applied. Electric stabilizer trim can
be used to neutralize control column pitch forces before moving the
STAB TRIM CUTOUT switches to CUTOUT. Manual stabilizer trim
can be used after the STAB TRIM CUTOUT switches are moved to
CUTOUT.
Administrative Information
Insert this bulletin behind the Bulletin Record page in Volume 1 of your Flight
Crew Operations Manual (FCOM). Amend the FCOM Bulletin Record page to
show bulletin TBC-19 "In Effect" (IE).
This Bulletin remains in effect until Boeing provides additional information on
system updates that may allow this Bulletin to be canceled.
Please send all correspondence regarding Flight Crew Operations Manual
Bulletin status, to the 737 Manager, Flight Technical Data, through the Service
Requests Application (SR App) on the MyBoeingFleet home page.