# SDR MALA030166

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 22, 2003
- Submitted: February 26, 2003
- Operation: Air carrier
- Aircraft: N441XJ
- Make and model: Saab 340B
- Registry model: [Saab 340B](https://openairdocs.org/model/saab-340b) (OpenAirDocs)
- Aircraft serial: 340B441
- System (JASC): [3450 · Dependent Position Determining System](https://openairdocs.org/jasc/3450)
- Part: Transponder
- Part number: 6226523213
- Part serial: OFF137D
- Condition: Malfunctioned
- Location: Cockpit
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/MALA030166

## Discrepancy

DURING FLIGHT 3029, ATC REPORTED BOTH TRANSPONDERS INOPERATIVE ON THREE SEPARATE OCCASIONS, ON FLIGHT FROM GRF-MSP.  TRANSPONDER LOCKED UP WITH ACT LIGHT ILLUMINATED.  TCAS ALSO SWITCHED TO OFF MODE.  ATC REPORTED LOST MODE C AND REGULAR RETURN ONLY WAY TO CLEAR WAS TO RUN TRANSPONDER TEST SWITCHING FROM 1 TO 2, NO EFFECT.  MAINTENANCE REMOVED AND REPLACED TRANSPONDER CTL P/N 622-6523-213 SN/OFF 137D SN/ON 12761, REPLACED NR 1 TRANSPONDER P/N 622-9210-004, SN/OFF 5904, SN/ON 6145, TRANSPONDER SYSTEM OPS CHECKS GOOD IAW SF340 MM CHAP 34, FAR 43, APP E, PARA C C/W.

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