# SDR UALA2012070103505

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 29, 2012
- Submitted: August 17, 2012
- Operation: Air carrier
- Aircraft: [N120UA](https://openairdocs.org/aircraft/N120UA), registered now
- Make and model: Boeing 747422
- Aircraft serial: 29166
- Aircraft time: 54,490 hours, 6,380 cycles
- Engine: Pwa PW4056
- System (JASC): [2611 · Smoke Detection](https://openairdocs.org/jasc/2611)
- Part: Clamp
- Condition: Faulty
- Location: Fire Loop
- Stage of operation: NR
- How discovered: 9
- Nature of condition: N
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UALA2012070103505

## Discrepancy

NR 3 ENGINE FIRE LOOP. DUE TO CHRONIC NR 3 ENGINE FIRE LOOP FAULTS, PERFORM THE FOLLOWING TROUBLESHOT TASKS FOR THE 'B' LOOP.  THE PREVIOUS REPAIR ON 6-18 FIXED THE FAULTS FOR THE 'A' LOOP, BUT THE 'B' LOOP FAULTS WITH MSG 26025 CONTINUE 1.  FIM 26-11 TASK 856 STEPS B1-B6 FOR THE NR 3 ENGINE.  NO ACTIVE MESSAGE NOTED.  LOOP RESISTANCE CHECKS GOOD.  INSPECTED HARNESS AND REPLACED WORN CLAMPS.  NO OTHER DEFECTS NOTED.  RANG SYSTEM AND SHOOK HARNESS.  COULD NOT DUPLICATE FAULT.

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