SDR ASAA2019052729484

Service difficulty report · Unknown · Boeing 737990ER

Difficulty date: May 27, 2019
Submitted: May 28, 2019
Operation: Air carrier
Aircraft: N483AS
Make and model: Boeing 737990ER
Aircraft serial: 36350
Aircraft time: 15,006 hours, 4,915 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Unknown
Condition: Malfunctioned
Location: Cockpit
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

IN CRUISE, FL360, DUAL FMC FAILURE. FMC OPERATION PARTIALLY RESTORED; HOWEVER ROUTE & PERF INFO WERE DELETED. WHILE A/T LIM FLAG AND AMBER "LDG ALT" REMAIN. LNAV/VNAV OPERATION RESTORED AFTER MANUALLY RE-BUILDING THE BOX IN CRUISE. HOWEVER THE INFORMATION DOES NOT SEEM RELIABLE. GROUNDED - YES. L-FMC LOGGED PGM FAULT. R-FMC LOGGED PRES POS LAT RATE FAULT. RESET BOTH FMC'S. OP CK NORMAL. REF FIM 34-61 TASKS 801 & 837, & AMM 34-61-00-710-801.