# SDR AALA201909099007

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 8, 2019
- Submitted: September 10, 2019
- Operation: Air carrier
- Aircraft: [N901AN](https://openairdocs.org/aircraft/N901AN), registered now
- Make and model: Boeing 737823
- Aircraft serial: 29503
- Aircraft time: 59,827 hours, 24,444 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3989085
- Part serial: 3316
- Condition: Failed
- Location: Ac Bay
- Stage of operation: CL
- How discovered: O
- Nature of condition: J, S
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA201909099007

## Discrepancy

AIRCRAFT WAS GROUNDED: FLIGHT RETURNED TO ORD ON ACCOUNT OF PRESSURIZATION PROBLEM. AN EMERGENCY WAS DECLARED. MAINTENANCE ACCOMPLISHED FIM TASK 21-62-00-810-849, FOUND STANDBY TEMPERATURE CONTROL VALVE STAYS OPEN WHEN PACK IS RUNNING AND ALL SENSE LINES ARE DISCONNECTED. REMOVED AND REPLACED TEMP CONTROL VALVE IAW AMM 21-51-10. OPS CHECK GOOD NO LEAKS.

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