SDR ASAA2020110433493

Service difficulty report · Fmc · Boeing 737990ER

Difficulty date: November 4, 2020
Submitted: November 6, 2020
Operation: Air carrier
Aircraft: N471AS
Make and model: Boeing 737990ER
Aircraft serial: 41703
Aircraft time: 23,421 hours, 7,473 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Fmc
Condition: Malfunctioned
Location: Left
Stage of operation: NR
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

LEFT FMC FAIL, INTERMITTENT FAILURES, BUT WOULD FIX ITSELF AFTER 4TH FAILURE. PERFORMED QRH PROCEDURE. FMC SWITCH ON "BOTH ON RT" NO ISSUES WITH RT FMC. GROUNDED-YES. LT FMC HAD A PROGRAM FAULT. RESET LT FMC COMPUTER, REF B737-900 FIM 34-61 TASK 807. OPENED & CLOSED 1 CB. LT FMC OPERATIONS CHECK OK.