# SDR 2002UALA01616

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 22, 2002
- Submitted: November 7, 2002
- Operation: Air carrier
- Aircraft: [N223UA](https://openairdocs.org/aircraft/N223UA), registered now
- Make and model: Boeing 777222
- Aircraft serial: 30224
- Aircraft time: 4,374 hours, 677 cycles
- System (JASC): [2131 · Cabin Pressure Controller](https://openairdocs.org/jasc/2131)
- Part: Controller
- Part number: 11511007
- Condition: Failed
- Location: Cabin Pressure
- Stage of operation: CR
- 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/2002UALA01616

## Discrepancy

BOTH LEFT AND RIGHT AUTO CABIN PRESSURE CONTROLLERS INOP.  EICAS CABIN ALT AUTO MESSAGE RECEIVED.  BOTH LT & RT ASCPC (AIR SUPPLY & CABIN PRESSURE CONTROLLER) FAILED DUE TO INTERNAL FAULT.  BOTH ASCPC'S LOST PRIMARY CONTROL RESULTING IN CABIN PRESSURE CONTROL SYSTEM ON MANUAL CONTROL.  BOTH ASCPC WERE REPLACED, AND A/C RETURNED TO REVENUE SERVICE WITHOUT FURTHER INCIDENT.  HONEYWELL IS RELEASING A NEW ASCPC SOFTWARE UPGRADE TO FIX THIS PROBLEM SB 1151100-36-39, BOEING SB 777-36-0013.

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