SDR 98ZZZX1706

Service difficulty report · Spur Gear · Skrsky S76A

Difficulty date
April 27, 1998
Submitted
March 26, 2000
Operation
Air carrier
Filed by
HEER617E
PHI Aviation, LLC
Aircraft
N1546G
Make and model
Skrsky S76A
Aircraft serial
760076
Part
Spur Gear
Part number
7635109032047
Condition
Fractured
Location
M/R Gearbox
Stage of operation
IN
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

INVESTIGATION INTO A SERIES OF CHIP DETECTOR LIGHTS ON THE MAIN GEARBOX REVEALED THE SPUR GEAR HAD FRACTURED IN THREE PLACES. THE WEB OF THE GEAR HAD TWO SEPARATE FRACTURES AND THE SHAFT OF THE GEAR HAD ONE FRACTURE. TWO OF THE PINS (P/N HL12VLJ-8-5/6) THAT SECURE THE SPUR GEAR ASSEMBLY TOGETHER HAD ALSO SHEARED. MANY OTHER PINS SHOWED SIGNS OF WORKING. THE MAIN GEARBOX WAS OVERHAULED 227 OPERATING HOURS PRIOR TO THIS OCCURRENCE. THE SPUR GEAR IS NOT A LIFE LIMIT PART; THEREFORE, HISTORICAL RECORDS ARE NOT REQUIRED AND THE TOTAL TIME IN SERVICE OF THE GEAR IS NOT KNOWN AT THIS TIME.