# SDR SIMA991791

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 28, 1999
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N550LL
- Make and model: Aerosp ATR 72-212A
- Registry model: [Aerosp ATR 72-212A](https://openairdocs.org/model/aerospatiale-atr-72-212a) (OpenAirDocs)
- Aircraft serial: 550
- System (JASC): [3421 · Attitude Gyro and Indicating System](https://openairdocs.org/jasc/3421)
- Part: Adu
- Part number: 7003652602
- Condition: Failed
- Location: Cockpit
- Stage of operation: CL
- Nature of condition: B
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/SIMA991791

## Discrepancy

DFW - FLT 3505 - ADVISORY DISPLAY UNIT SCREEN WENT BLANK AFTER TAKEOFF FOLLOWED BY ELECTRICAL SMELL IN THE COCKPIT AND CABIN.  REMOVED AND REPLACED ADU.  ALSO, REMOVED AND REPLACED ASSOCIATED CONTROL PANEL AS A PRECAUTION.  AIRCRAFT RETURNED TO SERVICE.  REF:  OPER CNTRL NR 99ZZZX2829.  (X)

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