# SDR ASAA2020010831810

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 6, 2020
- Submitted: January 9, 2020
- Operation: Air carrier
- Aircraft: [N431AS](https://openairdocs.org/aircraft/N431AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 43255
- Aircraft time: 24,595 hours, 7,977 cycles
- System (JASC): [4900 · Airborne Auxiliary Power Unit (APU) System](https://openairdocs.org/jasc/4900)
- Part: Unknown
- Condition: Malfunctioned
- Location: Apu
- Stage of operation: NR
- How discovered: O
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2020010831810

## Discrepancy

APU WILL NOT START. GROUNDED - YES. CK'D AND REL PER MEL 49-1B. FAULT MESSAGE 49-41012 NO APU ROTATION SHUTDOWN. NO EVIDENCE OF HEAT DAMAGE OR DELAMINATION. STARTED APU AND PERFORMED BITE CHECK OF CDU NO CURRENTS FAULTS LOGGED. STARTED APU 5 TIMES WITH NO ISSUES. RAN APU AND INSPECTED NO DEFECTS NOTED.

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