# SDR IPXA2018041728677

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 17, 2018
- Submitted: April 25, 2018
- Operation: Air carrier
- Aircraft: [N575UP](https://openairdocs.org/aircraft/N575UP), registered now
- Make and model: Boeing 747-400
- Registry model: [Boeing 747-400](https://openairdocs.org/model/boeing-747-400) (OpenAirDocs)
- Aircraft serial: 35664
- Aircraft time: 38,063 hours, 5,680 cycles
- System (JASC): [2612 · Fire Detection](https://openairdocs.org/jasc/2612)
- Part: Fire Loop
- Condition: Malfunctioned
- Location: Nr 3 Engine
- Stage of operation: NR
- How discovered: 9
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/IPXA2018041728677

## Discrepancy

DESCENDING THROUGH FL180,  NR 3 ENGINE FIRE LOOP B STATUS MESSAGE.  GROUND TEST PASSED.   REPLACED THE NR 3 ENGINE LOWER LOOP ASSY IAW AMM 26-11-02-4, OPS TESTED GOOD. NO STATUS MESSAGE IAW AMM 26-11-00-715-001.

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