# SDR 95ZZZX4608

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 25, 1995
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: [N109GA](https://openairdocs.org/aircraft/N109GA), registered now
- Make and model: Cessna 550
- Registry model: [Cessna 550](https://openairdocs.org/model/cessna-550) (OpenAirDocs)
- Aircraft serial: 5500124
- System (JASC): [3520 · Passenger Oxygen System](https://openairdocs.org/jasc/3520)
- Part: Altitude Switch
- Part number: 99120575
- Condition: Defective
- Location: Oxygen System
- Part time: 4,685 hours
- Stage of operation: IN
- Nature of condition: L
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/95ZZZX4608

## Discrepancy

DURING PHASE 5 INSPECTION, OXYGEN SYSTEM FAILED FUNCTIONAL CHECK.  OXYGEN MASK DEPLOYED AT 12,400 FEET WHEN THEY SHOULD DEPLOY AT 13,500 FEET, PLUS OR MINUS 600 FEET.  DEFECTIVE BAROMETRIC ALTITUDE SWITCH CAUSED DISCREPANCY.  INTERNAL FAILURE OF WEAKNESS OF SWITCH LIKELY CAUSE.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.