# SDR ASAA2023081644629

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 16, 2023
- Submitted: August 17, 2023
- Operation: Air carrier
- Aircraft: [N585AS](https://openairdocs.org/aircraft/N585AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35683
- Aircraft time: 57,787 hours, 17,317 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Modulating Valve
- Part number: 3989083
- Part serial: 7178
- Condition: Faulty
- Location: Ecs Bay
- Part time: 64,211 hours, 22,880 cycles
- Stage of operation: DE
- How discovered: V
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2023081644629

## Discrepancy

LEFT PACK LIGHT ON AFTER MASTER CAUTION RECALL ON DESCENT. QRH COMPLETED. GROUNDED - YES. (RESOLVED ON W/O: 1965708 TASKCARD: N/R-00001 ) INIITIAL EVALUATION, LH PACK LT ILLUMINATED AT OVERHEAD ON MASTER RECALL. PERFOMRED PZTC BITE IAW FIM 21-62 TASK 801, BOTH #1/2. #1 PZTC LH PACK FAILS TCV ON VERIFY. #2 PZTC FOR RH PACK PASSES GREEN ON VERIFY. REMOVED AND REPLACED LH PACK TCV IAW AMM21-51-10-000/400-801. LEAK CHECKS GOOD. 3 CB PULLED, COLLARED, AND RESET. RE RAN BITE #1 PZTC, NOW PASSES (GREEN) ON VERIFY. LH PACK LT CLEARED FROM MASTER RECALL. REF LP 60591968 FOR ADDITIONAL RH PACK DEFECT. SEAMC MITCH NOTIFIED. THIS CLEARS MEL 21-32B. PLACARDS REMOVED. NO A/C CONFIG CHANGES.

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