# SDR IPXA2026041756544

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 17, 2026
- Submitted: April 20, 2026
- Operation: Air carrier
- Aircraft: [N580UP](https://openairdocs.org/aircraft/N580UP), registered now
- Make and model: Boeing 747428F
- Aircraft serial: 25632
- Aircraft time: 123,286 hours, 21,097 cycles
- System (JASC): [2612 · Fire Detection](https://openairdocs.org/jasc/2612)
- Part: Fire Loop
- Condition: Faulted
- Location: Zone 400
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/IPXA2026041756544

## Discrepancy

DURING CRUISE STATUS MESSAGE "ENG 2 FIRE LP B" CMC MSG: 26023 ACTIVE. PERFORMED T/S IAW IFIM 26-11 TASK 854; FOUND UPPER AFT FIRE/OVERHT DETECTOR LP B ON ENG-2 FAULTY. RESISTANCE ABOVE 2.2 MOHM.  REPLACED LOWER FWD FIRE LOOP ASSY AS PER AMM 26-11-02/401 AND PERFORMED FIRE SYSTEM GROUND TEST AS PER AMM 26-11-00/501 RESULT PASS.

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