# SDR 3EJA739JS083725

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 27, 2025
- Submitted: September 10, 2025
- Operation: Air carrier
- Aircraft: [N739JS](https://openairdocs.org/aircraft/N739JS), registered now
- Make and model: Cessna 525B
- Registry model: [Cessna 525B](https://openairdocs.org/model/cessna-525b) (OpenAirDocs)
- Aircraft serial: 525B0045
- Aircraft time: 12,599 hours, 8,639 cycles
- System (JASC): [2131 · Cabin Pressure Controller](https://openairdocs.org/jasc/2131)
- Part: Controller
- Part number: 991240913
- Part serial: 1716
- Condition: No Discrepancy
- Location: Cabin Pressure
- Part time: 151 hours, 112 cycles
- Stage of operation: CL
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/3EJA739JS083725

## Discrepancy

CLIMBING THROUGH 12,000 MSL, THE CABIN ALTITUDE INCREASED SIGNIFICANTLY.NO MESSAGES OR NOTIFICATIONS AND THE MASKS DID NOT DROP. CABIN ALTITUDE STABILIZED AND HELD AT 7000-8000 FEET DURING OUR DESCENT.  PERFORMED SATISFACTORY PREFLIGHT SYSTEM TEST OF PRESSURIZATION SYSTEM IAW AMM 21-30-00. NO DEFECTS NOTED AT THIS TIME. PERFORMED SATISFACTORY GROUND MAINTENANCE TEST OF PRESSURIZATION SYSTEM IAW AMM 21-30-00. NO DEFECTS NOTED.

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