# SDR ASAA2021031434288

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 14, 2021
- Submitted: March 16, 2021
- Operation: Air carrier
- Aircraft: [N479AS](https://openairdocs.org/aircraft/N479AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 60576
- Aircraft time: 19,833 hours, 6,320 cycles
- System (JASC): [3460 · Flight Management Computing Hardware System](https://openairdocs.org/jasc/3460)
- Part: Fmc
- Condition: Faulted
- Location: Left
- Stage of operation: CR
- 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/ASAA2021031434288

## Discrepancy

IN CRUISE FLIGHT APPROACHING THE CRITICAL POINT ON OUR ETOPS FLIGHT PLAN THE CAPTAINS SIDE NAV DISPLAY SHOWED VTK FLAG FOLLOWED BY A MAP FLAG ALONG WITH FMC P/RST CAUTION AND NO FMC DATA ON BOTH CDU'S AFTER ABOUT 30 SECONDS THE LEFT FMC RESET ITSELF AND CAME BACK ONLINE. NORMAL NAV DISPLAY FOLLOWED.  GROUNDED - YES. FAULT LOGGED WAS " PRES POS LAT-RATE" ACCOMPLISHED B737-900 FIM 34-61 TASK 824/34-61 TASK 801, ADIRS SHOW NO FAULTS LOGGED AND GROUND TEST OK REFERENCE FIM 34-21 TASK 801 NO CURRENT DISCREPANCIES NOTED.

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