# SDR AALA201907229026

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 21, 2019
- Submitted: July 24, 2019
- Operation: Air carrier
- Aircraft: [N990NN](https://openairdocs.org/aircraft/N990NN), registered now
- Make and model: Boeing 737823
- Aircraft serial: 31241
- Aircraft time: 10,648 hours, 4,300 cycles
- System (JASC): [2130 · Cabin Pressure Control System](https://openairdocs.org/jasc/2130)
- Part: Unknown
- Condition: Malfunctioned
- Location: Cabin Pressure
- Stage of operation: DE
- How discovered: O
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA201907229026

## Discrepancy

AIRCRAFT NOT GROUNDED: PILOT REPORTS DURING DESCENT FROM FL360 TO BELOW 10,000FT, EXPERIENCED RAPID CHANGES IN CABIN CLIMB & DESCENT RATES WITH SMALL CHANGES IN THRUST, FROM + 500 FPM TO - 1500 FPM. MAINTENANCE PERFORMED PRESSURIZATION SYSTEM GROUND TEST AND CONTROLLER BITE TEST IAW AMM 21-31-00. NO FAULTS NOTED. OPS CHECK NORMAL.

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