Service difficulty report · Spline

Difficulty date
October 6, 2008
Submitted
February 2, 2009
Operation
General aviation
Engine
Rotax ROTAX912F3
Part
Spline
Condition
Chipped
Location
Prop Shaft
Part time
1,465 hours
Component
Gearbox · Rotax
Component part number
887281
Stage of operation
IN
How discovered
9
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

(CAN) METAL CHIP FOUND ON MAGNETIC PLUG DURING SERVICING. TRACED TO GEARBOX. GEARBOX REMOVED AND CHIP WAS FOUND TO BE FROM TOP SPLINE OF THE PROPSHAFT JUST ABOVE THE RING HALF. POSSIBLE CAUSE, COULD BE FROM A "STEP" WORN IN FROM RING HALF. IF RING HALF WAS INSTALLED WITH THIS STEP RESTING ON THE RING SURFACE IT COULD CAUSE A STRESS POINT. THERE IS A SLIGHT CORRESPONDING WEAR MARK 180 DEGREES FORM THE CHIP THAT INDICATES THE CHIP IS RELATED TO THE PREV RING HALF LOCATION. PROPSHAFT HAD PASSED NDT 44.5 HRS PRIOR (OVERHAUL). AREA COULD HAVE BEEN UNDER HIGH LOAD DUE TO STEP WORN INTO SPLINE. PROPSHAFT REPLACED. INCLUDE INSPECTION FOR THIS TYPE OF WEAR IN FUTURE WORK.