MN-FLT-OH-201
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START VALVE OPEN Alert Blinking at Starter Cutout
GOT-8
Flight Crew Operations Manual Bulletin
for
Gol Linhas Aereas S.A.
Number:
GOT
-
8
IssueDate:
May 10, 2018
Subject:
START VALVE OPEN Alert Blinking at Starter Cutout
Reason:
This bulletin informs flight crews of nuisance blinking of the START
VALVE OPEN alert after reaching starter cutout speed.
THE FOLLOWING PROCEDURE AND/OR INFORMATION IS EFFECTIVE UPON RECEIPT
Background Information
At starter cutout speed, momentary blinking of the START VALVE OPEN alert
has occurred on 737 MAX flight tests.
The START VALVE OPEN alert and the entire crew alert block begins to blink
if the start valve is still open 5 seconds after being commanded to close. In some
cases, the timing of the command signal plus the time to close the start valve is
slightly over the 5 second threshold, causing the alert to blink momentarily.
After starter cutout speed is reached, if the START VALVE OPEN alert blinks
momentarily then extinguishes, the blinking can be considered a nuisance.
Continued blinking for up to 10 seconds followed by steady illumination of the
START VALVE OPEN alert is indication of a start valve malfunction.
This anomaly affects 737-7/-8/-9 airplanes with MDS software Blockpoint (BP)
1 and prior. MDS software BP2, scheduled for release 3Q2020, changes the
threshold of the alert from 5 seconds to 7 seconds eliminating the nuisance alerts.
Boeing will communicate appropriate fix instructions as soon as they become
available.
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.
March 1, 2021