# SDR ASAA2021041734600

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 17, 2021
- Submitted: April 21, 2021
- Operation: Air carrier
- Aircraft: [N468AS](https://openairdocs.org/aircraft/N468AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41735
- Aircraft time: 25,413 hours, 8,182 cycles
- System (JASC): [3460 · Flight Management Computing Hardware System](https://openairdocs.org/jasc/3460)
- Part: Fmc
- Part number: 1762000101
- Part serial: 006101
- Condition: Faulted
- Location: Left
- Part time: 94 hours, 31 cycles
- Stage of operation: DE
- 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/ASAA2021041734600

## Discrepancy

LEFT FMC FAIL DESCENDING THROUGH 10,000'. GROUNDED - YES. LH FMC FAULTED ON EVERY LEG ACCORDING TO L AND R FMC. REMOVED AND REPLACED LH FMC WITH S/N 06101 REF B737-900 AMM 34-61-02. ALL SOFTWARE VERIFIED AND CROSSLOADED FROM RH SIDE. PERF FACTORS ADJUSTED AS WELL. FMC TRANSFER SWITCH RETURNED TO NORMAL POSITION. GROUND VERIFICATION SUCCESSFUL.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.