# SDR ASAA2018122677563

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 17, 2018
- Submitted: December 27, 2018
- Operation: Air carrier
- Aircraft: [N403AS](https://openairdocs.org/aircraft/N403AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41730
- Aircraft time: 24,430 hours, 8,034 cycles
- System (JASC): [4950 · APU Bleed Air System](https://openairdocs.org/jasc/4950)
- Part: Wire Harness
- Part number: 38884492
- Condition: Malfunctioned
- Location: Apu Bleed
- Stage of operation: TX
- How discovered: O
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2018122677563

## Discrepancy

APU AIR PRESSURE DOES NOT MAINTAIN PRESSURE THAT WOULD BE NEEDED TO START. GROUNDED - YES. REMOVED AND REPLACED APU WIRE HARNESS IAW B737-900 AMM 49-11-01-400-802. GROUND VERIFICATION TEST IS GOOD. NO FAULTS. DRY MOTOR MAINTAINED STEADY PRESSURE AT AROUND 29% N2 REF AMM 71-00-00. REMOVED AND REPLACED P2, T-4 AND DELTA PRESSURE SENSOR REF AMM 49-52-31, 49-52-32, 49-52-33. OPS AND LEAK CHECK GOOD.

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