# SDR ASAA2018052824832

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 28, 2018
- Submitted: May 29, 2018
- Operation: Air carrier
- Aircraft: [N596AS](https://openairdocs.org/aircraft/N596AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35688
- Aircraft time: 38,503 hours, 11,740 cycles
- System (JASC): [7722 · Engine EGT/TIT Indicating System](https://openairdocs.org/jasc/7722)
- Part: Probe
- Part number: TC29603
- Condition: Out Of Limits
- Location: Nr 1 Engine
- Stage of operation: IN
- How discovered: O
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2018052824832

## Discrepancy

DIAGNOSTICS REPORTS NR 1 ENGINE TREND DATA SHOWS A DELTA EGT INCREASE AND EGTHDM DECREASE. EGT INDICATION ERRORS ARE SUSPECT. GROUNDED - YES. ACCOMPLISHED 78273000, MAINT MESSAGE 77-20871 (T495S4 OUT OF RANGE) ALL LEGS. PRE-CLEAN VALUES: S1 116.22, S2 67.20, S3 74.40, S4 ALL DASHES. ACCOMPLISHED NR 1 ENG EGT CONNECTOR CLEANING REF AMM 77-21-00 S4 CONNECTOR DP1013 REQS TORQUE PLUS SAFETY. PERFORMED T49.5 PROBE AND EGT SYSTEM INSPECTION REF AMM 77-21-01-200-801, FOUND S4 T49.5 PROBE RESISTANCE OUT OF LIMITS. ALL OTHER READINGS WITHIN LIMITS. REMOVED AND REPLACED S4 T49.5 PROBE REF AMM 77-21-01-000-801-F00 AND 77-21-01-400-801-F00. POST-CLEANING VALUES: S1 27.50 S2 19.69 S3 20.10 S4 34.49. CLEARS THE TSR. ETOPS GROUND VERIFICATION SUCCESSFUL.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.