# SDR CA980424022

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 11, 1998
- Submitted: March 26, 2000
- Operation: Air carrier
- Make and model: Boeing 757-28A
- Registry model: [Boeing 757-28A](https://openairdocs.org/model/boeing-757-28a) (OpenAirDocs)
- Engine: Rroyce RB211535E437
- System (JASC): [7532 · Compressor Bleed Valve](https://openairdocs.org/jasc/7532)
- Part: Valve
- Part number: 32143042
- Condition: Failed
- Location: Nr 2 Engine
- Stage of operation: CR
- Nature of condition: J
- Precautionary procedure: O, B
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CA980424022

## Discrepancy

(CAN) ENGINE HIGH STAGE EICAS MESSAGE CAUSED THE FLIGHT CREW TO COMPLETE QRH CHECKLIST AND SELECT NR 1 ENGINE BLEED TO OFF.  APPROXIMATELY ONE HOUR LATER, CREW NOTICED CABIN ALTITUDE AT 10,000 FEET RISING SLOWLY.  DESCENT INITIATED AND NORMAL PRESSURIZATION RECOVERED AT APPROXIMATELY FL 270.  POST-FLIGHT INVESTIGATION REVEALED A FAULT WITH THE NR 1 ENGINE HIGH STAGE PILOT VALVE.  THE VALVE WAS REPLACED.  SUBSEQUENT INVESTIGATION REVEALED A FAULT WITH THE NR 2 ENGINE BLEED, WHICH WAS FOUND TO HAVE LOW PRESSURE FLOW WHEN OPERATING AT LOW STAGE SETTINGS.  THE NR 2 ENGINE HP SHUTOFF VALVE WAS ALSO REPLACED.

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