# SDR AWXA200300098

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 31, 2003
- Submitted: March 14, 2003
- Operation: Air carrier
- Aircraft: [N647AW](https://openairdocs.org/aircraft/N647AW), registered now
- Make and model: Airbus A320-232
- Registry model: [Airbus A320-232](https://openairdocs.org/model/airbus-a320-232) (OpenAirDocs)
- Aircraft serial: 762
- Aircraft time: 19,547 hours, 7,533 cycles
- System (JASC): [3441 · Inertial Guidance System](https://openairdocs.org/jasc/3441)
- Part: Computer
- Part number: 46657602
- Part serial: 93324
- Condition: Failed
- Location: Adiru
- Component: Adiru
- Component part number: 46502003030312
- Stage of operation: CL
- 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/AWXA200300098

## Discrepancy

PHX - AIR TURN BACK - FLT 0014 - AFTER TAKEOFF FROM PHX EN ROUTE TO JFK, MAXIMUM OPERATING LIMIT SPEED (VMO/MMO) ALERT WOULD SOUND AND REMAIN ON IN ACCESS OF 240 KNOTS, AND EXTINGUISH AT 230 KNOTS. NR 1 AIR DATA INERTIAL REFERENCE UNIT (ADIRU) DISPLAYED ERRONEOUS VMO INDICATION ON PRIMARY FLIGHT DISPLAY.  TURNED BACK TO PHX. MAINTENANCE REMOVED AND REPLACED NR 1 ADIRU IAW AWA T/C R2A34304, OPERATIONAL CHECK IS GOOD. VENDOR BENCH TEST OF ADIRU S/N 3419 CONFIRMED FAILURE OF UNIT. REPLACED AIR DATA RESOLVER PCB ASSEMBLY, CALIBRATED AND TESTED IAW CMM TP1011 REV 22.

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