# SDR ASAA2021041334580

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 13, 2021
- Submitted: April 19, 2021
- Operation: Air carrier
- Aircraft: [N468AS](https://openairdocs.org/aircraft/N468AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41735
- Aircraft time: 25,366 hours, 8,167 cycles
- System (JASC): [3460 · Flight Management Computing Hardware System](https://openairdocs.org/jasc/3460)
- Part: Fmc
- Part number: 1714970501
- Part serial: 0002828
- Condition: Faulted
- Location: First Officer'S
- Part time: 65,811 hours, 28,474 cycles
- Stage of operation: CL
- 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/ASAA2021041334580

## Discrepancy

AT 3000' MSL W/LNAV AND VNAV ENGAGED, FO'S ND DISPLAYED VTK AND PFD DISPLAYED LDG ALT FLAG AND LNAV AND VNAV DISENGAGED ABOUT A MINUTE LATER ALL FLAGS DISAPPEARED AND FO MAP DISPLAY WAS NORMAL. GROUNDED - YES. AT TECH SERVICES REQUEST, REMOVED AND REPLACED #1 FMC WITH P/N: 176200-01-01 IAW B737-900 AMM 34-61-02-000/400-801. VERIFIED CORRECT OPS SW PRESENT, AND SUBSEQUENTLY CROSSLOADED FROM #2 FMC ALL RELEVANT SW IAW AMM 34-61-00-470-806. LOADED NEW NAV DB INTO #1 FMC AND CROSSLOADED TO #2 FMC. REF TC N8234000. PERFORMED PERF FACTORS ADJUSTMENT IAW AMM 34-61-00-800-801. PERFORMED OPS TEST IAW 34-61-00-710-801, CHECKS GOOD.

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