# SDR ASAA2018061845070

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 14, 2018
- Submitted: June 18, 2018
- Operation: Air carrier
- Aircraft: [N453AS](https://openairdocs.org/aircraft/N453AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 36354
- Aircraft time: 17,603 hours, 5,840 cycles
- System (JASC): [2133 · Pressure Regulator/Outflow Valve](https://openairdocs.org/jasc/2133)
- Part: Outflow Valve
- Part number: 40631997201AB
- Part serial: 9719710
- Condition: Failed
- Location: Cabin Pressure
- Part time: 130 hours, 53 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/ASAA2018061845070

## Discrepancy

THE PRESSURIZATION AUTO FAIL LIGHT CAME ON IN FLIGHT.  RAN QRH AND THE LIGHT EXTINGUISHED,  WHEN ALTERNATE WAS SELECTED.  ACFT GROUNDED.  ACCOMPLISHED FIM 21-31, TASK 801 DCPC BITE, NR 2 FAULTED OFV LRU FAILED,  NR 1 NO FAULTS.  DUE TO ACFT HISTORY, REMOVED AND REPLACED THE OUTFLOW VALVE ASSY IAW AMM 21-31-03.  INSTALL TEST FAILED. NR 1 PRESSURE CONTROLLER SHOWS OFV LRU FAIL FAULT CODE 009 AS ACTIVE FAULT. COMPLETED FIM 21-31, TASK 802.  REMOVED AND REPLACED THE OUTFLOW VALVE. OPS CHECKED NORMAL. NO FAULTS NOTED. GROUND VERIFICATION SUCCESSFUL.

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