# SDR ASAA2013051094784

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 10, 2013
- Submitted: May 14, 2013
- Operation: Air carrier
- Aircraft: [N508AS](https://openairdocs.org/aircraft/N508AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35691
- Aircraft time: 18,318 hours, 5,727 cycles
- System (JASC): [3610 · Pneumatic Distribution System](https://openairdocs.org/jasc/3610)
- Part: Control Valve
- Condition: Failed
- Location: Nr 1 Engine
- Part time: 35,846 hours, 18,660 cycles
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2013051094784

## Discrepancy

AT CRUISE FL 370, DUCT PRESSURE DIFFERENCE OF 24 PSI LT 24 PSI RT 48 PSI.  ACFT GROUNDED. ACCOMPLISHED T/C NG-36WC-00001 ENGINE BLEED AIR HEALTH CHECK ON NR 1 ENGINE.  FOUND THE PRECOOLER CONTROL VALVE NOT OPENING BY 3 PSI AND THE HIGH STAGE REGULATOR NOT WITHIN LIMITS.  REPLACED PRECOOLER CONTROL VALVE REF AMM 36-12-02, OPS AND LEAK CHECKS NORMAL.  REPLACED HIGH STAGE REGULATOR REF AMM 36-11-07.  OPS AND LEAK CHECKS NORMAL.

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