# SDR 2026F00165

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 28, 2026
- Submitted: July 28, 2026
- Operation: General aviation
- Aircraft: [N525KY](https://openairdocs.org/aircraft/N525KY), registered now
- Make and model: Cessna 525A
- Registry model: [Cessna 525A](https://openairdocs.org/model/cessna-525a) (OpenAirDocs)
- Aircraft serial: 525A0369
- Aircraft time: 6,739 hours, 5,432 cycles
- System (JASC): [2130 · Cabin Pressure Control System](https://openairdocs.org/jasc/2130)
- Part: Regulator
- Part number: 1H7518
- Part serial: 10AY121
- Condition: Failed
- Location: Cabin Pressure
- Part time: 6,739 hours, 5,432 cycles
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: B
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2026F00165

## Discrepancy

IN-FLIGHT AT 38,000 FT, DOOR SEAL ANNUNCIATOR ILLUMD. RAN CORRESPONDING EMERG CHKLIST.  BEGAN DESCENT TO 31,000 FT & DONNED OXYGEN MASKS, A POP WAS HEARD, FOLLOWED BY A HISSING SOUND. THEN, THE CABIN ALT ANNUNCIATOR & MASTER WARNING LIGHTS CAME ON AS CABIN ALTITUDE RISING. COMPLETED THE MEMORY ITEMS FOR CABIN ALT PROCEDURE, BEGAN EMERGENCY DESCENT, & HALTED DOOR SEAL CHECKLIST TO  COMPLETE CABIN ALT CHKLST. IN DESCENT, DECLARED AN EMERGENCY WITH ATC & DESCENDED TO 10,000 FT. ALSO CONTINUED TO MONITOR CABIN ALTITUDE METER. HIGHEST READING WAS APPROX 14,000-14,500 FT & STABLE DURING THE EMERGENCY DESCENT. ON REACHING A SAFE ALTITUDE, RECOVERED FROM THE DESCENT & BRIEFED PAX ON WHAT HAPPENED. DECIDED HAD SUFFICIENT FUEL AT SAID ATTITUDE TO CONTINUE TO DESTINATION. CONTINUED TO DESTINATION WITHOUT FURTHER EVENT.

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