# SDR 98UAL900555

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 16, 1998
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N107UA](https://openairdocs.org/aircraft/N107UA), registered now
- Make and model: Boeing 747422
- Aircraft serial: 26900
- Engine: Pwa PW4056
- System (JASC): [2822 · Fuel Boost Pump](https://openairdocs.org/jasc/2822)
- Part: Pump
- Part number: 6072101
- Condition: Damaged
- Location: Nr 2
- Part time: 540 hours
- Component: Cranehydroai, 6072101
- Stage of operation: NR
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/98UAL900555

## Discrepancy

FUEL OVERRIDE/JETTISON PUMP PART NR 60-72101 DASH 2 RECOVERED FROM THE NR 2 MAIN FUEL TANK (AFT POSITION) OF ACFT 8407 WAS FOUND TO EXHIBIT EXCESSIVE IMPELLER END-PLAY AND GOUGING OF THE IMPELLER UNIT WITH THE INLET ADAPTER.  TESTING OF THE PUMP BY THE VENDOR SHOWED THAT THE AXIAL THRUST-BALANCING MECHANISM FAILED.  THE THRUST WASHER/BEARING IS SUSPECTED TO HAVE BEEN MANUFACTURED INCORRECTLY.  ROOT CAUSE OF FAILURE HAS NOT BEEN IDENTIFIED AS YET.

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