# SDR ASAA2017071721402

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 17, 2017
- Submitted: July 18, 2017
- Operation: Air carrier
- Aircraft: [N471AS](https://openairdocs.org/aircraft/N471AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41703
- Aircraft time: 11,187 hours, 3,701 cycles
- System (JASC): [2210 · Autopilot System](https://openairdocs.org/jasc/2210)
- Part: Display
- Condition: Malfunctioned
- Location: Cockpit
- Stage of operation: NR
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2017071721402

## Discrepancy

HEADING BUG INTERMITTENTLY TRAVELS OPPOSITE DIRECTION COMMANDED BY HEADING SELECT KNOB.  ACFT GROUNDED.  DFCS FLT FAULT REVIEW SHOWED NO FAULTS LAST FLT.  PERFORMED FIM 22-11, TASK 803 FOR MCP TESTS.  ALL PASSED & PERFORMED DFCS LRU TEST FOR MCP.  ALL TESTS PASSED IAW AMM 22-11-34.  COULD NOT DUPLICATE PROBLEM. HEADING BUG & INDICATIONS OPS NORMAL ON BOTH CAPT'S & F/O'S DUS.

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