# SDR ASAA0852471

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 11, 2008
- Submitted: January 14, 2008
- Operation: Air carrier
- Aircraft: [N577AS](https://openairdocs.org/aircraft/N577AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35186
- Aircraft time: 3,366 hours, 1,014 cycles
- System (JASC): [3620 · Pneumatic Indicating System](https://openairdocs.org/jasc/3620)
- Part: Sensor
- Part number: 1296662
- Condition: Faulty
- Location: Bleed Air Sys
- Stage of operation: CR
- How discovered: O
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA0852471

## Discrepancy

FIVE MINUTES AFTER REACHING FL350 NOTICED LARGE SPLIT IN DUCT PRESSURE.  LEFT = 15PSI RIGHT = 45PSI.  BEGAN RETURN TO HNL.  THIRTY MINUTES LATER LT BLEED TRIP OFF LIGHT & WOULD NOT RESET.  REMOVED AND REPLACED 390 SENSOR 450 THERMOSTAT HIGH STAGE VALVE HIGH STAGE REGULATOR & PRSOV SENSE LINE.  ALL LEAK & OP CHECKS 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.