# SDR NACA2021080600002

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 6, 2021
- Submitted: August 9, 2021
- Operation: Air carrier
- Aircraft: [N321CM](https://openairdocs.org/aircraft/N321CM), registered now
- Make and model: Boeing 767323
- Aircraft serial: 29431
- Aircraft time: 81,794 hours, 13,612 cycles
- System (JASC): [3610 · Pneumatic Distribution System](https://openairdocs.org/jasc/3610)
- Part: Controller
- Part number: 79275515
- Part serial: 900853
- Condition: Faulted
- Location: Duct Pressure
- Part time: 1,156 hours, 293 cycles
- Stage of operation: NR
- How discovered: O
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/NACA2021080600002

## Discrepancy

DISCREPANCY: DUCT PRESSURE DIFFERENCE IS BECOMING LARGER. LEFT SIDE IS 15 PSI LARGER THAN RIGHT SIDE. CORRECTIVE ACTION: REPLACED PRESSURE REGULATING VALVE CONTROLLER AND OPS CHECK GOOD AMM 36-11-19, GROUND CHECK GOOD. AC REMAINS ETOPS.

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