# SDR ASAA2017022119898

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 21, 2017
- Submitted: February 23, 2017
- Operation: Air carrier
- Aircraft: [N506AS](https://openairdocs.org/aircraft/N506AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35690
- Aircraft time: 33,025 hours, 10,094 cycles
- System (JASC): [4970 · APU Indicating System](https://openairdocs.org/jasc/4970)
- Part: Thermocouple
- Part number: 38762711
- Condition: Failed
- Location: Apu Exhaust
- 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/ASAA2017022119898

## Discrepancy

APU EGT TREND DATA SHOWS EGT HAS SHIFTED ABOVE THE MAINTENANCE THRESHOLD OF 593 BUT LESS THAN 605 DEGREES.  ACFT GROUNDED.  REMOVED & REPLACED BOTH APU THERMOCOUPLES IAW AMM 49-71-21. OPS NORMAL, NO FAULTS FOUND.

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