Service difficulty report · Gear Set · Dhav DHC6

Difficulty date
January 3, 2012
Submitted
January 3, 2012
Operation
General aviation
Make and model
Dhav DHC6
Engine
Pwa PT6A27
Part
Gear Set
Part number
E310145502Q
Part serial
EE090
Condition
Misaligned
Location
Reduction Gear
Part time
1,491 hours
Component
1st Stage · PT6A27
Component part number
3029354
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

IN THE PROCESS OF REPLACING 1ST STAGE SUNGEAR AND PLANET GEAR SET, A DEFECT IN THE BEARINGS INSTALLED IN ALL 3 PLANET GEARS WERE FOUND. THE BRONZE SLEEVE PORTION OF THE BEARING HAD ROTATED CAUSING MISALIGNMENT OF BEARING SCALLOPS. THE BRONZE SLEEVE SHOULD NOT MOVE DURING A TYPICAL SERVICE LIFE OF 1ST STAGE PLANET GEAR. SUNGEAR AND PLANET GEAR SET WERE BEING REPLACED TO COMPLY WITH AD2011-25-12. REF SB-804, REV B. THIS IS THE SECOND INSTANCE OF BRONZE SLEEVE ROTATION WE HAVE SEEN FOR THIS PART.