SDR ASAA2015011010203

Service difficulty report · Warning Light · Boeing 737890

Difficulty date: January 10, 2015
Submitted: January 12, 2015
Operation: Air carrier
Aircraft: N533AS
Make and model: Boeing 737890
Aircraft serial: 35201
Aircraft time: 15,703 hours, 4,700 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Warning Light
Condition: False Indication
Location: Fmc
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

DURING CRUISE, FL 360, 24 MINUTES PRIOR TO THE TOP OF DESCENT THE RT FMC, VTK FLAG ILLUMINATED. THE AFS DROPPED OUT OF LNAV AND VNAV INTO CWS. THE VKT LIGHT EXTINGUISHED AFTER A COUPLE OF SECONDS. SWITCHED TO AUTOPILOT A AND RE-ESTABLISHED LNAV AND VNAV WITH NO FURTHER INCIDENTS. ACFT GROUNDED. REF FIM 34-61, TASK 801, PERFORM R FMC BITE, NO FAULTS FOUND, BITE TEST PASSED. NO HISTORY LAST 30 DAYS.