# SDR ASAA2021090635882

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 6, 2021
- Submitted: September 8, 2021
- Operation: Air carrier
- Aircraft: [N584AS](https://openairdocs.org/aircraft/N584AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35682
- Aircraft time: 51,281 hours, 15,145 cycles
- System (JASC): [3460 · Flight Management Computing Hardware System](https://openairdocs.org/jasc/3460)
- Part: Fmc
- Condition: Faulted
- Stage of operation: CL
- How discovered: O
- Nature of condition: N
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2021090635882

## Discrepancy

SHORTLY AFTER TAKEOFF WE LOST VNAV ON THE FMA AND VERTICAL GUIDANCE ON FLIGHT DIRECTOR WITH ERRONEOUS LNAV INFORMATION ON THE FO PFD. CAPTAINS LNAV GUIDANCE NORMAL. GROUNDED - YES. PERFORM B737-800 FIM 34-61 TASK 836 CYCLED BOTH FMC'S CIRCUIT BREAKERS. NO DEFECTS NOTED.

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