# SDR ASAA2023011442088

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 14, 2023
- Submitted: February 27, 2023
- Operation: Air carrier
- Aircraft: [N564AS](https://openairdocs.org/aircraft/N564AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35103
- Aircraft time: 59,425 hours, 17,634 cycles
- System (JASC): [7520 · Engine Cooling System](https://openairdocs.org/jasc/7520)
- Part: Valve
- Part number: 1821M60P04
- Part serial: GRTN0598
- Condition: Out Of Range
- Location: #1 Engine
- Part time: 35,777 hours, 11,236 cycles
- Stage of operation: IN
- How discovered: V
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2023011442088

## Discrepancy

ENG 1 FAULT MSG 75-10591 FOUND. THE TBV POSITION SIGNAL IS OUT OF RANGE. LONG TIME FAULT. GROUNDED - YES. DEFERRED ON PLT FOR 450 FLT HRS PER T/C 78273000. REMOVED AND REPLACED #1 ENGINE TRANSIENT BLEED VALVE REF B737-800 AMM 75-23-01.

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