BUFFALO, NY, USA
N146CA
SAAB-FAIRCHILD SF-340A
THE FLIGHT CREW DETECTED VIBRATION COMING FROM THE RIGHT PROPELLER AND MADE A DECISION TO SHUT THE ENGINE DOWN. DURING THE SHUTDOWN PROCESS THE PROPELLER SEPARATED FROM THE AIRPLANE. EXAMINATION OF BOTH PORTIONS OF THE FAILED PROPELLER SHAFT REVEALED THE SHAFT FAILED DUE TO FATIGUE. METALLURGICAL EXAMINATION FOUND A SLAG INCLUSION JUST BELOW THE FRACTURE SURFACE. THIS DEFECT OCCURRED DURING THE MELTING OF THE ORIGINAL INGOT.
A FATIGUE FRACTURE ON THE PROPELLER SHAFT, THAT ORIGINATED AT A SUBSURFACE SLAG INCLUSION, WHICH REMAINED IN THE MATERIAL USED TO MANUFACTURE THE SHAFT.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
