Service difficulty report · Crankshaft

Difficulty date
December 6, 2005
Submitted
June 6, 2006
Operation
General aviation
Engine
Lyc TIO540R2AD
Part
Crankshaft
Part number
13F17760
Part serial
125902
Condition
Separated
Location
Engine
Stage of operation
AP
How discovered
O
Nature of condition
Y, J
Precautionary procedure
A

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

What was found

CRANKSHAFT FAILED AT THROW BETWEEN NR 2 MAIN JOURNAL (AS NUMBERED BACK TO FRONT) AND NR 4 CRANK PIN. CRACK STARTED AT RADIUS OF MAIN JOURNAL AND PROPAGATED APPROX 70% THROUGH THROW BEFORE SEPARATING. AFTER SEPARATION, THROW BETWEEN NR 3 ROD AND NR 3 MAIN FRACTURED THROUGH FROM OVERLOAD. APPEARS TO HAVE BEEN INITIATED BY STRESS RISER CREATED BY SLIGHT STEP IN RADIUS. (POSSIBLY CREATED FROM BEING TOUCHED ACCIDENTALLY BY GRINDING WHEEL WHEN CRANKSHAFT WAS REWORKED.) CRANKSHAFT WAS (TC# 20051221004).