SDR ASAA2018022123666

Service difficulty report · Fmc · Boeing 737990ER

Difficulty date: February 21, 2018
Submitted: February 23, 2018
Operation: Air carrier
Aircraft: N491AS
Make and model: Boeing 737990ER
Aircraft serial: 44109
Aircraft time: 9,021 hours, 3,060 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Fmc
Condition: Malfunctioned
Stage of operation: CR
How discovered: O
Nature of condition: J
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, THE LEFT FMC FAILED WHEN REQUESTING WINDS ON ROUTING DATA PAGE, LEFT FMC RESOLVES AFTER RIGHT FMC, PER QRH. WINDS ONLY LOAD WITH RIGHT FMC SELECTED. ACFT GROUNDED. FOUND PGM FAULT ON THE LEFT FMC. PERFORMED TWO CIRCUIT BREAKER RESET. OPS CHECKED GOOD. INTERMITTENT FAULT. PERFORMED BITE ON LEFT AND RIGHT FMC BITE SHOWED NO CURRENT FAULTS IAW FIM 34-61, TASK 801. NO HISTORY IN LAST 30 DAYS.