# SDR ASAA2020081213010

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 11, 2020
- Submitted: August 12, 2020
- Operation: Air carrier
- Aircraft: [N431AS](https://openairdocs.org/aircraft/N431AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 43255
- Aircraft time: 26,189 hours, 8,462 cycles
- System (JASC): [3460 · Flight Management Computing Hardware System](https://openairdocs.org/jasc/3460)
- Part: Fmc
- Condition: Failed
- Location: Left
- Stage of operation: NR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2020081213010

## Discrepancy

LEFT FMC APPEARED TO FAIL FOR 3-4 MINUTES THEN RESET. OBS INDICATIONS REPEATED 3 TIMES, LAST ONE PUT FMC SW TO FMC "R", VTK ON LEFT ND, NO FMC DATA ON LEFT ND, BOTH MCDU'S HAD NO FMC PROMPT, RIGHT ND NORMAL. GROUNDED - YES. ACCOMPLISHED FMC BITE, BITE SHOWS FMC-L- PGM FAULT. REF B737-900 FIM 34-61 TASK 801. PER REF FIM 34-61 TASK 807 DO NOT REPLACE FMC FOR THIS FAULT. ACCOMP FMC SENSOR STATUS TEST FOR BOTH FMC'S ALL OK. ACCOMP FIX OUTPUT TEST, TEST PASSES FOR BOTH FMC'S REF B737-900 AMM 34-61-00-710-026.

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