# SDR CA971219045

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 24, 1997
- Submitted: March 26, 2000
- Operation: General aviation
- Engine: Pwa PW120
- System (JASC): [7210 · Turbine Engine Reduction Gear](https://openairdocs.org/jasc/7210)
- Part: Bearing
- Part number: 310924401
- Condition: Spalled
- Location: Red Grbox Nr 15
- Part time: 17,734 hours
- Stage of operation: IN
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CA971219045

## Discrepancy

(CAN)  ENGINE SENT FOR REPAIR AFTER REDUCTION GEARBOX WAS FOUND MAKING M50 METAL.  DISASSEMBLY OF ENGINE REVEALED SOURCE OF THE M50 METAL CONTAMINATION A SPALLED NR 15 BEARING.  NR 15 BEARING HAD ELECTRO-EROSION ON THE OUTER RACE AND ROLLERS.  NR 15 BEARING BORE WAS FRETTED AND BEARING HAD SPUN ON THE PROP SHAFT.  SUBMITTER SUGGESTED CAUSE OF BEARING FAILURE WAS ELECTRO-EROSION WHICH APPEARED TO BE A STRAY ELECTRICAL DISCHARGE FROM SOME ACFT COMPONENT AND NOT A LIGHTNING STRIKE.  THERE WAS SECONDARY DAMAGE ON THE BULL GEAR, LT AND RT 2ND STAGE SPUR GEARS,  OVERSPEED GOVERNOR SPUR GEAR AND REDUCTION GEARBOX SCAVENGE PUMP HOUSING.  PART TC:  19,818.

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