SDR ASAA2019022428319

Service difficulty report · Fmc · Boeing 737990ER

Difficulty date: February 24, 2019
Submitted: March 1, 2019
Operation: Air carrier
Aircraft: N493AS
Make and model: Boeing 737990ER
Aircraft serial: 41727
Aircraft time: 11,309 hours, 3,774 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Fmc
Condition: Malfunctioned
Location: Nr 1
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

LEFT FMC FAIL. THE LEFT FMC FAILED TWICE AT CRUISE ALTITUDE WITH VTK ON CAPT NAV DISPLAY HOWEVER SYSTEM RESET 30 SECONDS AND OPS NORMAL. THE FMC FAILED A THIRD TIME AND DIDN'T RESET IMMEDIATELY. RAN FMC QRH AND PLACED FMC SWITCH ON OVERHEAD PANEL TO BOTH ON R. GROUNDED - YES. REPLACED NR 1 FMC, LOADED ALL CURRENT SOFTWARE. AMM TASK 34-61-02-000-801. OPS. TEST 34-61-00-710-801 AMM. SYS TEST 34-61-00-730-801 AMM. PERF FACTORS TEST 34-61-00-800-801 AMM.