# SDR ASAA2014062208184

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 22, 2014
- Submitted: June 24, 2014
- Operation: Air carrier
- Aircraft: [N566AS](https://openairdocs.org/aircraft/N566AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35182
- Aircraft time: 28,705 hours, 8,675 cycles
- System (JASC): [3610 · Pneumatic Distribution System](https://openairdocs.org/jasc/3610)
- Part: Regulator Valve
- Part number: 1074847
- Part serial: 6976
- Condition: Failed
- Location: Nr 2 Engine
- Part time: 31,762 hours, 16,570 cycles
- Stage of operation: CR
- 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/ASAA2014062208184

## Discrepancy

DUCT SPLIT OF 23 PSI OBSERVED AT FL390 AT M785.  RIGHT DUCT SHOWS 21 PSI AND LT SHOWS 44 PSI.  THE DUCT SPLIT VARIES FROM 23 PSI-18 PSI AT DIFFERENT POWER SETTINGS WITH THE RT ALWAYS INDICATING LESS THEN THE LT DUCT.  ACFT GROUNDED.  PERFORMED TC NG-36WC-00001 BLEED HEALTH SYS TEST ON NR 2 ENGINE. FOUND HIGH STAGE REG VALVE FAILED REVERSE FLOW DIAPHGRAM CK, REPLACED HIGH STAGE REG VALVE, REF 36-1107. PERFORMED OPS TEST IAW FIM TASK 36-10-807.

---
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.