# SDR USAA2012120300023

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 30, 2012
- Submitted: December 3, 2012
- Operation: Air carrier
- Aircraft: [N539UW](https://openairdocs.org/aircraft/N539UW), registered now
- Make and model: Airbus A321-231
- Registry model: [Airbus A321-231](https://openairdocs.org/model/airbus-a321-231) (OpenAirDocs)
- Aircraft serial: 4082
- Aircraft time: 10,731 hours, 4,023 cycles
- System (JASC): [2440 · External Power System](https://openairdocs.org/jasc/2440)
- Part: Control Unit
- Part number: 1700667D
- Part serial: AADU005377
- Condition: Malfunctioned
- Location: External Power
- Part time: 755 hours, 301 cycles
- Stage of operation: NR
- How discovered: O
- Nature of condition: B
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/USAA2012120300023

## Discrepancy

VERY STRONG ELECTRIC BURNING SMELL IN COCKPIT, BEGIN AT ENGINE SHUTDOWN AND CONTINUE TO GET STRONGER.  REMOVED AND REPLACED GROUND AUXILLIARY POWER CONTROL UNIT (GAPCU).  OPS CHECKED GOOD.

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