What was found
DURING A POWER CHANGE IN THE TRAFFIC PATTERN, THE PROPELLER DEPARTED THE AIRCRAFT. INSPECTION OF THE CRANKSHAFT FLANGE SHOWED THAT ALL 6 BOLTS HAD BROKEN FLUSH WITH THE FLANGE. IT APPEARS FROM VISUAL INSPECTION THE BOLTS HAD BEEN OVERTORQUED AT INSTALLATION ONLY 11 HOURS PRIOR TO THIS ACCIDENT. THREE PORTIONS OF THE BROKEN BOLTS WERE REMOVED AND SENT TO THE NTSB FOR FURTHER ANALYSIS.