# SDR ASAA2021090235864

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 2, 2021
- Submitted: September 7, 2021
- Operation: Air carrier
- Aircraft: [N423AS](https://openairdocs.org/aircraft/N423AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 35206
- Aircraft time: 30,348 hours, 9,747 cycles
- System (JASC): [4990 · APU Oil System](https://openairdocs.org/jasc/4990)
- Part: Oil Cooler
- Part number: 1605642
- Part serial: 9319
- Condition: Damaged
- Location: Apu
- Part time: 3,896 hours, 6,582 cycles
- 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/ASAA2021090235864

## Discrepancy

APU FAULT LIGHT GENERATOR DISCONNECT WHILE APU RUNNING AT GATE. GROUNDED - YES. REMOVED DAMAGED OIL COOLER. REPLACED OIL COOLER PER B737-900 AMM 49-41-41. APU RUNS CONTINUOUSLY WITH NO AUTO-SHUTDOWN. APU OPS AND LEAKS CHECK GOOD. NO FURTHER DEFECTS NOTED.

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