# SDR ASAA2019102173046

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 17, 2019
- Submitted: October 22, 2019
- Operation: Air carrier
- Aircraft: [N433AS](https://openairdocs.org/aircraft/N433AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41704
- Aircraft time: 23,723 hours, 7,682 cycles
- System (JASC): [2210 · Autopilot System](https://openairdocs.org/jasc/2210)
- Part: Autopilot Sys
- Condition: Faulted
- Stage of operation: CR
- How discovered: 9
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2019102173046

## Discrepancy

AUTO PILOT DISENGAGED AT 34000 FT WITH NO PILOT INPUTS. ON DESCENT THE AUTO PILOT KICKED OFF AGAIN WITH OUT ANY PILOT INPUT. GROUNDED - YES. DEFECT DID NOT INDICATE WHICH A/P ENGAGED. USING DFCS FAULT REVIEW DETERMINED B A/P ENGAGED. FAULT MSG 22-11607 ASSOCIATED WITH DISCONNECT AT 34,000FT AND MSG 22-11833 ASSOCIATED WITH DISCONNECT AT 9000FT. T/S PER B737-900 FIM 22-11 TASK 817 AND PER FIM 22-12 TASK 803. PERFORMED MCP TESTS PER FIM 22-11 TASK 803, ALL TESTS PASS. PERFORMED FIM 22-12 TASK 804 FOUND ALL C/B'S SET. PERFORMED DFCS BITE TEST PER FIM 22-11 TASK 801, NO FAULTS. NO PREVIOUS HISTORY, CK'S GOOD FOR SERVICE.

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