# SDR FDEA201411153722

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 15, 2014
- Submitted: November 17, 2014
- Operation: Air carrier
- Aircraft: [N883FD](https://openairdocs.org/aircraft/N883FD), registered now
- Make and model: Boeing 777FHT
- Registry model: [Boeing 777FHT](https://openairdocs.org/model/boeing-777fht) (OpenAirDocs)
- Aircraft serial: 39285
- Aircraft time: 17,169 hours, 2,497 cycles
- System (JASC): [3461 · Flight Management Computing Software System](https://openairdocs.org/jasc/3461)
- Part: Unknown
- Condition: Malfunctioned
- Location: Cockpit
- Stage of operation: CR
- How discovered: O
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/FDEA201411153722

## Discrepancy

UNCOMMANDED TURN, DURING CRUISE PHASE OF FLIGHT WITH LNAV & VNAV SELECTED, THE ACFT STARTED A RANDOM TURN TO THE LEFT.  SWITCHED TO HEADING SELECT TO TURN  BACK TOWARDS PROPER COURSE THEN RE-ENGAGED LNAV WHERE UPON THE ACFT NAVIGATED NORMALLY.  THE ONLY PILOT INPUTS BEFORE THE WAYWARD TURN WAS AN UPDATE OF THE WINDS.  INTERROGATED MAT & FOUND NO REPORTED MSGS WITH REF FLEET TEAM DIGEST 777-FTD-34-10008.  EVENTS SUCH AS THIS ARE CURRENTLY UNDER INVESTIGATION IAW EO REQUEST.  PERFORMED FMC BITE DATA DOWNLOAD, FMCS BITE, FMLBPQL, FMLBPQR IAW AMM 31-35-00-2. HAS NOT YET DISCLOSED FINAL ACTION DUE TO ONGOING ANALYSIS.  PERFORMED FLIGHT MANAGEMENT COMPUTING SYS ADJUSTMENT TEST IAW AMM 34-61-00-5 WITH ALL TESTS PASSED.  ACFT OK TO CONTINUE SERVICE.

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