# SDR ASAA201808135751

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 11, 2018
- Submitted: August 13, 2018
- Operation: Air carrier
- Aircraft: [N506AS](https://openairdocs.org/aircraft/N506AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35690
- Aircraft time: 38,728 hours, 11,895 cycles
- System (JASC): [7720 · Engine Temperature Indicating System](https://openairdocs.org/jasc/7720)
- Part: Probe
- Part number: TC29603
- Condition: Out Of Limits
- Location: Nr 1 Engine
- Stage of operation: IN
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA201808135751

## Discrepancy

NR 1 ENGINE EXPERIENCED AN INCREASE IN DELTA EGT AND A DECREASE IN EGT HOT DAY MARGIN.  FUEL FLOW AND CORE SPEED REMAINED STABLE.  ACFT GROUNDED.  ON THE NR 1 ENGINE, PERFORMED FIM 77-05, TASK 801, FOUND FAULT CODE 77-20861 ON MULTIPLE FLIGHT LEGS IN FAULT HISTORY.  PERFORMED FIM 77-21, TASK 803,  DURING T49.5 PROBE AND EGT SYSTEM INSPECTION,  FOUND T49.5 PROBES S2 AND S3 OUT OF RESISTANCE LIMITS IAW AMM 77-21-01-200-801-F00.  REMOVED AND REPLACED THE S2 AND S3 T49.5 PROBES IAW AMM 77-21-01/401. OPS CHECKED SATISFACTORY.  PERFORMED SUCCESSFUL REPAIR CONFIRMATION OF FIM 77-05, TASK 801, AND FIM 77-21, TASKS 801-804.

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