# SDR ASAA2021021134079

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 11, 2021
- Submitted: February 23, 2021
- Operation: Air carrier
- Aircraft: [N453AS](https://openairdocs.org/aircraft/N453AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 36354
- Aircraft time: 26,937 hours, 8,585 cycles
- System (JASC): [2210 · Autopilot System](https://openairdocs.org/jasc/2210)
- Part: Control Panel
- Part number: 8221567104
- Part serial: 4859F7
- Condition: Defective
- Location: Cockpit
- Part time: 13,302 hours, 4,244 cycles
- Stage of operation: NR
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2021021134079

## Discrepancy

VERTICAL SPEED WINDOW HAS SEGMENTS DISPLAYED INCORRECTLY. GROUNDED - YES. REMOVED AND REPLACED DFCS MODE CONT PANEL REF B737-900 AMM 22-11-34-400-801, OPS NML REF AMM 22-11-34-740-801. ACCOMPLISHED DFCS MCP LRU REPLACEMENT TEST, GRP BITE 32, ALL TEST PASSED. ACCOMPLISHED DFCS LAND VERIFY TEST, GRP BITE 49, ALL TEST PASSED REF AMM 22-11-00-700-801.

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