# SDR SWAA2015121147003

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 9, 2015
- Submitted: December 11, 2015
- Operation: Air carrier
- Aircraft: [N399WN](https://openairdocs.org/aircraft/N399WN), registered now
- Make and model: Boeing 737-3H4
- Registry model: [Boeing 737-3H4](https://openairdocs.org/model/boeing-737-3h4) (OpenAirDocs)
- Aircraft serial: 27693
- Aircraft time: 65,992 hours, 53,252 cycles
- System (JASC): [2932 · Hydraulic Pressure Sensor](https://openairdocs.org/jasc/2932)
- Part: O-Ring
- Part number: 623337
- Condition: Leaking
- Location: Hydraulic Sys
- Stage of operation: CL
- How discovered: O
- Nature of condition: K, J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/SWAA2015121147003

## Discrepancy

AIR TURN BACK, DECLARED EMER & A SYS HYD PRESS WENT TO 1200 PSI ON CLIMB OUT, THEN TO 200 PSI BY LANDING, EMER DECLARED.  FOUND O RING ON A HYD SYS TRANSMITTER LEAKING.  REPLACED A SYS PRESS TRANSMITTER O RING IAW MM.

---
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.