# SDR 0300929621

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 10, 2003
- Submitted: May 12, 2003
- Operation: Air carrier
- Aircraft: N621NW
- Make and model: Doug DC-9-32
- Registry model: [Doug DC-9-32](https://openairdocs.org/model/mcdonnell-douglas-dc-9-32) (OpenAirDocs)
- Aircraft serial: 47544
- Aircraft time: 60,389 hours, 70,716 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Duct
- Condition: Separated
- Location: Lt Acm
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: B, A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/0300929621

## Discrepancy

CRUISING AT FL 330 CREW NOTICED THE CABIN ALTITUDE AT 9300' AND CLIMBING AT 450FPM. COM PROCEDURES DID NOT ARREST CABIN CLIMB AND CREW PERFORMED AN EMERGENCY DESCENT TO A LOWER ALTITUDE WHERE THEY WERE ABLE TO REGAIN CONTROL OF CABIN PRESSURIZATION. FLIGHT DIVERTED TO MKE AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND A DUCT FROM THE LEFT ACM SEPARATED AND REINSTALLED IT. THE NR 1 CONTROLLER BITE SHOWED FAULT CODE 016, NR 2 HAD NO FAULTS. AIRCRAFT HAS RETURNED TO SERVICE.

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