# SDR FDEA202602120182

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 12, 2026
- Submitted: February 12, 2026
- Operation: Air carrier
- Aircraft: [N681FE](https://openairdocs.org/aircraft/N681FE), registered now
- Make and model: Airbus A300 F4-605R
- Registry model: [Airbus A300 F4-605R](https://openairdocs.org/model/airbus-industrie-a300-f4-605r) (OpenAirDocs)
- Aircraft serial: 799
- Aircraft time: 33,359 hours, 19,039 cycles
- System (JASC): [2611 · Smoke Detection](https://openairdocs.org/jasc/2611)
- Part: Smoke Detector
- Part number: 26100175
- Part serial: 278
- Condition: No Test
- Location: Zone 100
- Stage of operation: IN
- How discovered: C
- Nature of condition: L
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/FDEA202602120182

## Discrepancy

AFT CARGO SMOKE LOOP A WILL NOT TEST.  LIKELY FAILED COMPONENT IS THE  50WU3, ELECTRONIC SMOKE DETECTION UNIT.  TROUBLESHOT IAW TSM 26-19-01 STANDARDS.  AMM: 26-19-34-04 PERFORMED BITE TEST ON MAIN CARGO SMOKE DETECTOR CONTROL UNITS, 50WU1, 50WU2 AND 50WU3. FAULT ON 50WU1 REAR "A" LIGHT NOT ILLUMINATED ON TEST.  REMOVED AND REPLACED 50WU1 SMOKE DETECTOR CONTROL UNIT AND OPS CHECK GOOD.

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