# SDR UIEA2017053000875

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 30, 2017
- Submitted: June 1, 2017
- Operation: Air carrier
- Aircraft: [N475MC](https://openairdocs.org/aircraft/N475MC), registered now
- Make and model: Boeing 747-47UF
- Registry model: [Boeing 747-47UF](https://openairdocs.org/model/boeing-747-47uf) (OpenAirDocs)
- Aircraft serial: 29252
- Aircraft time: 74,873 hours, 13,634 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Acm
- Part number: 7744694
- Part serial: 200006026
- Condition: Tripped
- Location: Nr 1
- Stage of operation: TX
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: D
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UIEA2017053000875

## Discrepancy

NR 1 PACK TRIPPED.  REPLACED THE ACM IAW AMM 21-51-04.  TROUBLESHOT IAW FIM 21-50 TASK 810. NO FAULTS NOTED. REPLACED PACK DISCHARGE OVERHEAT SWITCH S519 & S520.  REPLACED PACK DISCHARGE SENSOR T1612 & T1619. REPLACED RAM AIR INLET ACTUATOR. PERFORMED 4 ENGINE START AND MONITORED PACK DURING ENGINE START AND POWER TRANSFER. NO FAULTS NOTED.

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