# SDR ASAA2015052411814

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 24, 2015
- Submitted: May 26, 2015
- Operation: Air carrier
- Aircraft: [N461AS](https://openairdocs.org/aircraft/N461AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 36363
- Aircraft time: 4,572 hours, 1,512 cycles
- System (JASC): [2133 · Pressure Regulator/Outflow Valve](https://openairdocs.org/jasc/2133)
- Part: Outflow Valve
- Part number: 2123010BA
- Part serial: 14102000
- Condition: Faulted
- Location: Cabin Pressure
- Part time: 4,570 hours, 1,511 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/ASAA2015052411814

## Discrepancy

CABIN RATE OF CLIMB INDICATOR FLUCTUATES +- 300 FPM IN FLIGHT AT VARIOUS CRUISE ALTITUDES.  COCKPIT "AIRFLOW" NOISE FLUCTUATES AT SAME TIME.  ACFT GROUNDED. PERFORMED FIM 21-31, TASK 801, DCPC BITE ON BOTH CONTROLLERS.  NR 1 AND NR 2 DCPC TEST OK WITH NO EXISTING FAULTS.  NR 1 DCPC LOGGED OFV LRU FAIL ON PREVIOUS FLIGHT.   FAIL WAS CODE 011.  PERFORMED FIM 21-31, TASK 802.  REPLACED OUTFLOW VALVE, TESTS CHECKED OK, REF  MM 21-31-03.

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