# SDR AALA202001179001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 16, 2020
- Submitted: January 17, 2020
- Operation: Air carrier
- Aircraft: [N939UW](https://openairdocs.org/aircraft/N939UW), registered now
- Make and model: Boeing 757-2B7
- Registry model: [Boeing 757-2B7](https://openairdocs.org/model/boeing-757-2b7) (OpenAirDocs)
- Aircraft serial: 27303
- Aircraft time: 81,345 hours, 28,910 cycles
- System (JASC): [3610 · Pneumatic Distribution System](https://openairdocs.org/jasc/3610)
- Part: Regulator Valve
- Part number: 32143069
- Part serial: 364C
- Condition: Defective
- Location: Bleed Air Sys
- Part time: 90,633 hours, 31,752 cycles
- Stage of operation: TO
- How discovered: O
- Nature of condition: J
- Precautionary procedure: C
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202001179001

## Discrepancy

AIRCRAFT WAS GROUNDED: WHEN POWER WAS ADDED FOR TAKEOFF LEFT ENGINE BLEED AIR DUCT PRESSURE SPLIT +20 PSI FROM RIGHT ENGINE AND UNSTABLE CYCLING +-20 PSI. REPLACED NR 2 ENGINE PRESSURE REGULATING SHUTOFF VALVE (PRSOV) AND ACCOMPLISHED A SATISFACTORY LEAK AND OPERATIONAL CHECK PER AMM 36-11-09.

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