SDR ASAA2021071235372

Service difficulty report · Fmc · Boeing 737990ER

Difficulty date: July 12, 2021
Submitted: July 20, 2021
Operation: Air carrier
Aircraft: N440AS
Make and model: Boeing 737990ER
Aircraft serial: 41705
Aircraft time: 28,802 hours, 9,264 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Fmc
Condition: Faulted
Location: Left
Stage of operation: LD
How discovered: O
Nature of condition: O
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 "VTK" CYCLING ON AND OFF EVERY 20 SECS OR SO ON CA'S ND LEFT FMC. GROUNDED - YES. FOUND FMC L STUCK IN REPEATING BITE CYCLE RESET NO HELP. FOUND FAULT "PGM" ON G LEG INFLIGHT FAULT L/H FMC. VERIFIED BOTH FMC'S HAD BOTH GREEN LIGHTS ILLUMINATED. MOVED TRANSFER S/W BACK TO NORMAL POSITION. OPS NORMAL. RESET L/H FMC BY PULLING C/B FOR 1 MIN. ACCOMPLISHED B737-900 FIM 34-61 TASK 801 FMC BITE AND FMC OPS TEST REF B737-900 AMM 34-61-00-710-801 TO BOTH L/H & R/H FMC'S. NO DEFECTS NOTED.