SDR ASAA2020012743971

Service difficulty report · Warning Message · Boeing 737990ER

Difficulty date: January 24, 2020
Submitted: January 28, 2020
Operation: Air carrier
Aircraft: N491AS
Make and model: Boeing 737990ER
Aircraft serial: 44109
Aircraft time: 16,830 hours, 5,433 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Warning Message
Condition: False Activation
Location: Fmc
Stage of operation: CR
How discovered: O
Nature of condition: N
Precautionary procedure: O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

DURING CRUISE, AT FL 360, THE FIRST OFFICER`S IN BOUND DU DISPLAYED VTK, BOTH CDUS DISPLAYED SINGLE FMC OPERATION AND LNAV WAS LOST FOR APPROXIMATELY 40 SECONDS. GROUNDED - YES. IAW FIM TASK 34-61-00-810-836, ACCOMPLISHED FMC TEST NO FAIL MESSAGES NOTED. FMC BITE TESTED IAW AMM 34-61-00-810-801, OKAY. NO FAILURE MESSAGE NOTED.