This chapter discusses the failure of an aircraft control cable and the investigation that followed. It explains how visual examination showed that the failure occurred in a heavily worn section that runs over a pulley. Further examination under a stereoscope and in a SEM found that 40 out of 49 wires had thinned and broke apart, and that the remaining nine wires failed in tension evidenced by cup and cone fracture and the presence of dimples on the fracture surface. Based on their findings, investigators concluded that cable snapped because of excessive thinning due to contact wear.

This chapter discusses the failure of an aileron control cable in an aircraft and explains how investigators determined the cause. Based on their observations and the results of SEM fractography, investigators concluded that the cable had been damaged by a shearing tool, leading to its failure.