# SDR ASAA2022052838486

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 28, 2022
- Submitted: May 31, 2022
- Operation: Air carrier
- Aircraft: [N472AS](https://openairdocs.org/aircraft/N472AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 60580
- Aircraft time: 26,619 hours, 8,243 cycles
- System (JASC): [4980 · APU Exhaust System](https://openairdocs.org/jasc/4980)
- Part: Apu
- Part number: UNKNOWN
- Condition: Noisy
- Location: Unknown
- Stage of operation: TX
- 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/ASAA2022052838486

## Discrepancy

BOTH "B" AND "C" FA'S REPORTED UNUSAL BANG AFTER COMPLETION OF PUSHBACK BOTH FELT IT IN THEIR SEATS NEITHER THE "A OR "D" FOWARD GALLEY FELT ANYTHING. GROUNDED - YES. SUSPECT APU EXHAUST BACKFIRE DURING APU SHUTDOWN OBSERVED APU SHUTDOWN, COOL-DOWN AND RE-START OPS CK NORMAL PERFORMED GVI (WALKAROUND)OF AIRFRAME, ENGS AND WHEEL WELLS NO DEFECTS NOTED OK FOR SVC REF B737-900 AMM 49-11-00.

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