SDR ASAA2015091713106

Service difficulty report · Warning Light · Boeing 737890

Difficulty date: September 17, 2015
Submitted: September 21, 2015
Operation: Air carrier
Aircraft: N506AS
Make and model: Boeing 737890
Aircraft serial: 35690
Aircraft time: 27,947 hours, 8,603 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Warning Light
Condition: False Activation
Location: Fmc
Stage of operation: NR
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

FMC SINGLE OPS DISPLAYED IN SCRATCH PAD WITH FMC CAUTION LIGHT. LT FMC FAILED. ACFT GROUNDED. AFTER FAILURE, CREW SWITCHED TO "BOTH ON RIGHT" IAW QRH. SELECTED "NORMAL" AND BOTH FMCS OPS NORMAL. ACCOMPLISHED ADDITIONAL FAULT ISOLATION IAW FIM 34-61, TASK 837. FOUND SEVERAL INTERMITENT MISCOMPARE FAULTS ON LAST LEG. ACCOMPLISHED 34-61, TASK 801, LT FMC OPS NORMAL.