# SDR 99ZZZX49

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 3, 1998
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: [N477AL](https://openairdocs.org/aircraft/N477AL), registered now
- Make and model: Bell 407
- Registry model: [Bell 407](https://openairdocs.org/model/bell-helicopter-textron-canada-407) (OpenAirDocs)
- Aircraft serial: 53203
- System (JASC): [6320 · Main Rotor Gearbox](https://openairdocs.org/jasc/6320)
- Part: Gear
- Part number: 6893672
- Condition: Galled
- Location: Gearbox
- Part time: 649 hours
- Component: 23063393
- 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/99ZZZX49

## Discrepancy

DISASSEMBLED, CLEANED AND INSPECTED AND FOUND EXCESSIVE GALLING ON PINION AND T/M GEARS.  PINION GEAR HAD EXCESSIVE GALLING ON GEAR TEETH POSSIBLY DUE TO IMPROPER MESHING OF T/M AND PINION GEARS.  SECONDARY DAMAGE:  T/M GEAR P/N 6893673 S/N NN145514, TT:  648.9 HOURS - GALLING ON GEAR TEETH.

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