# SDR AALA20170413004

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 13, 2017
- Submitted: April 18, 2017
- Operation: Air carrier
- Aircraft: [N810NN](https://openairdocs.org/aircraft/N810NN), registered now
- Make and model: Boeing 737823
- Aircraft serial: 33207
- Aircraft time: 24,374 hours, 9,523 cycles
- System (JASC): [2131 · Cabin Pressure Controller](https://openairdocs.org/jasc/2131)
- Part: Controller
- Part number: 2193301AD
- Part serial: 9919427
- Condition: Failed
- Location: Cabin Pressure
- 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/AALA20170413004

## Discrepancy

AT FL 370 PRESSURIZATION AUTO FAIL LIGHT CAME ON. SWITCHED TO ALTERNATE CONTROLLER. THE CABIN PRESSURE BECAME ERRATIC WITH ALT LT ON AND FLT ALT & LAND ALT WINDOW BLANK. THE FLIGHT DECLARED AN EMERGENCY AND DIVERTED TO SJU WITHOUT FURTHER INCIDENT. MAINTENANCE REMOVED AND REPLACED NO 2 CABIN PRESS CONTROLLER IAW AMM 21-31-01. ACCOMPLISHED PRESSURIZATION SYSTEM GROUND TEST IAW AMM 31-31-00-700-802 AND CKD SATIS. THE AIRCRAFT WAS NOT GROUNDED.

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