SDR ASAA2021082835817

Service difficulty report · Fmc · Boeing 737990ER

Difficulty date: August 28, 2021
Submitted: August 31, 2021
Operation: Air carrier
Aircraft: N483AS
Make and model: Boeing 737990ER
Aircraft serial: 36350
Aircraft time: 22,177 hours, 7,057 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Fmc
Condition: Faulted
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

FO A/S BUG WOULD NOT RECOGNIZE RTA WPT (YYJ) FMC SPEED CAPT A/S BUG WAS .59 MACH, FO A/S BUG WAS .72 MACH. A/S BUGS WOULD ONLY MATCH WHEN DESIRED SPEED WAS SET INTO VNAV PAGE 2 (CRUISE). GROUNDED - YES. FMC LEFT & RIGHT, NO FLIGHT FAULTS BOTH BOTH OPS NML REF B737-900 FIM 34-61 TASK 801. FCC A&B NO FLIGHT FAULTS REF FIM 22-11 TASK 801. NO A/C HISTORY 90 DAYS. ETOPS GND VERIFICATION TEST SUCCESSFUL. SEAMC ROWAN NOTIFIED.