# SDR IPXA2025062146821

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 21, 2025
- Submitted: June 23, 2025
- Operation: Air carrier
- Aircraft: [N274UP](https://openairdocs.org/aircraft/N274UP), registered now
- Make and model: Doug MD-11F
- Registry model: [Doug MD-11F](https://openairdocs.org/model/mcdonnell-douglas-md-11f) (OpenAirDocs)
- Aircraft serial: 48575
- Aircraft time: 78,746 hours, 17,568 cycles
- System (JASC): [2120 · Air Distribution System](https://openairdocs.org/jasc/2120)
- Part: Duct
- Part number: ACM7009507
- Condition: Blown
- Location: Zone 100
- Stage of operation: CL
- 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/IPXA2025062146821

## Discrepancy

ATB, IN CLIMB CABIN PRESS UNCONTROLLABLE. CABIN EXCEEDED 10,000 AT 13,000 MSL. RETURNED TO KSDF. R & R CPC-1 REF. AMM 21-31-04 FUNCTIONAL TEST & RTS TEST PASSED, NO FAULTS NOTED. R & R ACC-2 REF. AMM 21-62-01 RTS TEST PASSED. DURING OPS TEST, SENSOR READOUT OF ACC-2, PK2 FLOW READS 15 LBS/MIN. READING SHOULD BE UNDER 5 LBS/MIN. FOUND DUCT ACM7009-507 WATER SEPARATOR OUTLET DUCT COUPLING ROD END BROKEN. R & R COUPLING ROD ENDS IAW IPC 21-54-01-01-560 & -564 & DWG ACM7009. PERFORMED OPS TEST OF ALL THREE PACKS IAW MM 21-53-00-840-801, ALL PACKS OPS NORMAL, PACK FLOWS SIMILAR FOR ALL THREE PACKS.

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