# SDR 2001UALA00131

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 20, 2001
- Submitted: March 7, 2001
- Operation: Air carrier
- Aircraft: N996UA
- Make and model: Boeing 737291
- Aircraft serial: 22456
- Aircraft time: 52,900 hours, 39,930 cycles
- Engine: Pwa JT8D17
- System (JASC): [2916 · Hydraulic Reservoir, Main](https://openairdocs.org/jasc/2916)
- Part: Check Valve
- Part number: 3111794
- Condition: Restricted
- Location: Reservoir
- Stage of operation: NR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2001UALA00131

## Discrepancy

RETURNED TO FIELD DUE TO LOSS OF THE B-SYSTEM HYDRAULICS.  *S/D*  FOUND B-SYSTEM RESERVOIR CHECK VALVE FAILED AND RESTRICTING FLOW.  REPLACED BOTH RESERVOIR CHECK VALVES.  SERVICED HYDRAULICS TO FULL AND LEAKED CHECKED GOOD.

---
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.