SDR ASAA2016121419033

Service difficulty report · Fmc · Boeing 737990ER

Difficulty date: December 14, 2016
Submitted: December 16, 2016
Operation: Air carrier
Aircraft: N402AS
Make and model: Boeing 737990ER
Aircraft serial: 41189
Aircraft time: 16,299 hours, 5,308 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Fmc
Condition: Malfunctioned
Stage of operation: CR
How discovered: O
Nature of condition: O
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, LOST BOTH FMC FOR ABOUT 15 SECONDS. LNAV AND VNAV WERE LOST AS WELL AS THE AIRPORT FUNCTION ON BOTH ND. NO ACTION REQUIRED AFTER SINCE ALL FUNCTIONS CAME BACK. NO VTK OR NAV DATA LOSS. LNAV AND VNAV ENGAGED NORMALLY AFTER. ACFT GROUNDED. BITE OF LEFT & RIGHT FMC SHOWS NR 1 FMC DATA INVALID INFLIGHT FAULT. STRING RESET RECORDED. GROUND VERIFICATION OPS NORMAL, IAW FIM 34-61 TASK 837, AFTER REBOOT OF LEFT & RIGHT FMC COMPUTERS.