# SDR ASAA2018012423287

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 24, 2018
- Submitted: January 26, 2018
- Operation: Air carrier
- Aircraft: [N469AS](https://openairdocs.org/aircraft/N469AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41702
- Aircraft time: 13,994 hours, 4,645 cycles
- System (JASC): [2130 · Cabin Pressure Control System](https://openairdocs.org/jasc/2130)
- Part: Gauge
- Condition: Fluctuates
- Location: Cabin Pressure
- Stage of operation: CR
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2018012423287

## Discrepancy

CABIN PRESSURE DIFFERENTIAL GUAGE FLUCTUATES IN FLIGHT AT FL 350.  N1 LEFT 87.1,  RIGHT 87.0.  WOULD VARY BETWEEN -100 TO + 200 - 400 FPM.  ACFT GROUNDED. C/W B737-900 FIM 21-31 TASK 801 CABIN PRESSURE CONTROLLER BIT PROCEDURE, BOTH SYSTEMS 1 & 2 TESTED GOOD.  NO CURRENT FAULTS NOTE , GROUND VERIFICATION GOOD.

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