# SDR ASAA2016080917655

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 9, 2016
- Submitted: August 15, 2016
- Operation: Air carrier
- Aircraft: [N589AS](https://openairdocs.org/aircraft/N589AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35686
- Aircraft time: 33,517 hours, 10,137 cycles
- System (JASC): [2210 · Autopilot System](https://openairdocs.org/jasc/2210)
- Part: Autopilot Sys
- Condition: Disconnected
- Location: A System
- 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/ASAA2016080917655

## Discrepancy

AT ALTITUDE LEVEL FLIGHT, FL 350, STEADY STATE FLIGHT CONDITIONS, AUTOPILOT A DISCONNECTED FOR NO REASON.  ACFT GROUNDED.  PERFORMED DFCS BITE CURRENT STATUS AND FLIGHT HISTORY FAULT REVIEW, REF FIM 22-11, TASK 801.  NO CURRENT FAULTS FOUND.  FOUND AUTOPILOT DISCONNECT FAULT FOR CHANNEL-A, ALT HOLD, LNAV ENGINE MCP DATA INV MESSAGE 22-11607. 1 OCCURRENCE.  PERFORMED LRU TEST FOR GROUP 20.00.  NO FAULTS FOUND. PERFORMED EXTENDED MAINTENANCE TESTS  GROUP 70.00, IAW FIM 22-11, TASK 817.  NO FAULTS FOUND. PERFORMED LAND VERIFY LIBRARY BITE TEST, IAW AMM 22-11-00/201, AND HGS SYS TEST, IAW SMM 34-36-00. NO FAULTS FOUND, IAW AMM 22-00-01.

---
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.