SDR ASAA2018021623602

Service difficulty report · Fmc · Boeing 737990ER

Difficulty date: February 16, 2018
Submitted: February 21, 2018
Operation: Air carrier
Aircraft: N457AS
Make and model: Boeing 737990ER
Aircraft serial: 36355
Aircraft time: 15,960 hours, 5,326 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Fmc
Part number: UNKNOWN
Condition: Faulted
Stage of operation: LD
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

AFTER LANDING, CAPTAINS FMC INTERMITTENTLY INOPERATIVE. RECEIVED A VTK MESSAGE ON THE NAV DISPLAY AND BLANK CDU, BUT NO MAP FLAG SHOWING ON CAPT NAV DISPLAY. VTK FLAG CYCLED ON AND OFF AT ABOUT 20 SECONDS INTERVALS WITH NO FMC FUNCTIONS AVAILABLE FOR 20 SEC AT A TIME. INTERMITTENT VTK FLAG CONTINUES AFTER IRU'S SHUT OFF. ACFT GROUNDED. CONFIRMED FAULT. PERFORMED FIM 34-61 TASK 836. GRD VERIFICATION SUCCESSFUL-LEFT FMC OPERATES NORMAL.