# SDR ASAA201805224726

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 20, 2018
- Submitted: May 22, 2018
- Operation: Air carrier
- Aircraft: [N493AS](https://openairdocs.org/aircraft/N493AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41727
- Aircraft time: 8,155 hours, 2,784 cycles
- System (JASC): [2210 · Autopilot System](https://openairdocs.org/jasc/2210)
- Part: Autopilot Sys
- Condition: Malfunctioned
- Stage of operation: TX
- 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/ASAA201805224726

## Discrepancy

WHILE ON THE GROUND, VNAV DISSENGAGES AFTER 15 SECONDS, LNAV DISENGAGES A FEW SECONDS AFTER.  ACFT GROUNDED. VERIFIED DISCREPANCY,  PERFORMED DFCS BITE IAW AMM 22-11-00.  PERFORMED DFCS LRU REPLACEMENT TEST IAW FIM 22-11, TASK 802.  ALL TESTS PASSED. SYS RETURNED TO NORMAL.

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