# SDR ASAA2013081895837

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 18, 2013
- Submitted: August 21, 2013
- Operation: Air carrier
- Aircraft: [N594AS](https://openairdocs.org/aircraft/N594AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35191
- Aircraft time: 20,828 hours, 6,417 cycles
- System (JASC): [2133 · Pressure Regulator/Outflow Valve](https://openairdocs.org/jasc/2133)
- Part: Outflow Valve
- Part number: 2123003AC
- Part serial: 08101973
- Condition: Malfunctioned
- Location: Cabin Pressure
- Part time: 20,831 hours, 6,418 cycles
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2013081895837

## Discrepancy

AT FL 380,  CABIN RATE INDICATOR WENT FROM 1200 FPM CLIMB TO 2000 FPM DESCEND EVERY 2-3 SECONDS SWITCHING TO ALTERNATE AHD NO EFFECT, DESCEND TO FL 340 AND EVERYTHING BECAME NORMAL.  ACFT GROUNDED.  NR 1 AND NR 2 CABIN PRESSURE CONTROLLERS LAST LEG SHOWS LOW INFLT HIGH LEAK G FAULT CODE 030.  AS A PRECAUTION R & R AFT OUTFLOW VALVE.  OPS CHECKED GOOD REF MM 21-31-03.  PERFORMED SYS TEST OF POSITIVE PRESSURE RELIEF VALVES IAW AMM 21-32-01. OTBD VALVE FAILS TEST.  REPLACED INBD AND OTBD PRESSURE RELIEF VALVES IAW AMM 21-32-01.  OPS CHECK NORMAL.  NO OTHER DISCREPANCIES NOTED.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.