SDR AALA201908069005

Service difficulty report · Fmc · Boeing 737823

Difficulty date: August 2, 2019
Submitted: August 6, 2019
Operation: Air carrier
Aircraft: N964NN
Make and model: Boeing 737823
Aircraft serial: 31210
Aircraft time: 15,043 hours, 5,701 cycles
System (JASC): 2210 · Autopilot System
Part: Fmc
Condition: Malfunctioned
Stage of operation: CR
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

AIRCRAFT NOT GROUNDED: PILOT REPORTS A MESSAGE AT CRUISE SAYING VNAV INVALID-PERF AIRCRAFT WENT TO ALITITUDE HOLD CHAGED THE COST INDEX SEVERAL TIMES AND FINALLY GOT VNAV PATH BUT IT WAS NOT ACCURATE. MAINTENANCE ACCOMPLISHED DFCS BITE IAW FIM 22-11-00, FOUND FMC A AND FCC B WITH DATA INV ON LEG 1 FC 22-11822 IAW FIM 22-11-00-810-811 INTERMITTENT FAULT. ACCOMPLISHED FMC LRU REP TEST IAW AMM 34-61-00, ADIRU LRU REP TEST IAW AMM 34-21-00. LAND VERIFY PASS IAW AMM 22-11-00-700-801.