SDR ASAA2016062317149

Service difficulty report · Unknown · Boeing 737990ER

Difficulty date: June 23, 2016
Submitted: June 27, 2016
Operation: Air carrier
Aircraft: N448AS
Make and model: Boeing 737990ER
Aircraft serial: 36356
Aircraft time: 864 hours, 290 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: J
Precautionary procedure: K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

AT CRUISE, CAPT HSI HAD VTK AND LOST BOTH MCDU'S. PULLED OUT QRH AND BY THE TIME IT WAS LOOKED UP, VTK, DISAPPEARED AND BOTH MCDU'S CAME BACK ONLINE. SUSPECT FAILURE, TEMPORARY, OF LT FMC. ACFT GROUNDED. PERFORMED BITE CHECK OF FMC'S, LT & RT AND OF INPUTS TO FMC'S LT & RT, WITH NO CURRENT FAULTS NOTED, REF FIM 34-61, TASK 801.