# SDR CALA2026030214155

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 27, 2026
- Submitted: March 2, 2026
- Operation: Air carrier
- Aircraft: [N14521](https://openairdocs.org/aircraft/N14521), registered now
- Make and model: Airbus A321-271NX
- Registry model: [Airbus A321-271NX](https://openairdocs.org/model/airbus-s-a-s-a321-271nx) (OpenAirDocs)
- Aircraft serial: 12175
- Aircraft time: 4,031 hours, 1,466 cycles
- Engine: Iae PW1133GAJM
- Engine time: 4,000 hours, 1,456 cycles
- System (JASC): [2612 · Fire Detection](https://openairdocs.org/jasc/2612)
- Part: Fire Detector
- Part number: 636D0015509
- Part serial: 56843
- Condition: Failed
- Location: Nr 2 Gearbox
- Part time: 4,000 hours, 1,456 cycles
- 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/CALA2026030214155

## Discrepancy

NR 2 ENGINE FIRE LOOP A, FAULTED, HAS HISTORY FOR ENG 2 LOOP A, FAULT.   PLACED ENG 2 FIRE LOOP A ON MEL 2612B.  TROUBLESHOOTING CONTINUED IAW TSM 26-12-00-810-805-A,  MEASURED RESISTANCE OF ALL LOOPS ON ENGINE 2 LOOP A. FOUND APPROX. 1010 OHMS TOTAL, PYLON LOOP MEASURED AT 4533 OHMS, CORE VENT LOOP MEASURED AT 3244 OHMS, AND CORE GEARBOX LOOP MEASURED AT 2172 OHMS. CORE GEARBOX LOOP SHOULD MEASURE BETWEEN 6469 AND 7150 OHMS.  R & R CORE GEARBOX LOOP FIN 4002WD1 IAW AMM 26-12-17, OPS CHECKED OK MEL REMOVED.

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