SDR 20000502SH007

Service difficulty report · Gear · Bell 407

Difficulty date: December 13, 1999
Submitted: May 2, 2000
Operation: General aviation
Aircraft: N417AL
Make and model: Bell 407
Aircraft serial: 53054
Engine: Allsn 250C47B
System (JASC): 7210 · Turbine Engine Reduction Gear
Part: Gear
Part number: 6893674
Part serial: NN146089
Condition: Damaged
Location: Gearbox
Part time: 1,197 hours
Component: Gearbox · Allsn
Component part number: 23063393
Stage of operation: IN
How discovered: V
Nature of condition: O
Precautionary procedure: K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

DISASSEMBLED, CLEANED, AND INSPECTED. FOUND SPALLING AND GALLING ON GEAR TEETH. TM GEAR HAS EXCESSIVE SPALLING AND GALLING ON GEAR TEETH POSSIBLY DUE TO IMPROPER MESHING OF TM AND PINION GEARS. SECONDARY DAMAGE. PINION GEAR, PN 6893672, SN 77723, TT 1,196.5, SPALLING AND GALLING ON GEAR TEETH. (X)

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