It was stated above that the main spar of the S-76 rotor blade is made from Titanium. One of the properties of Titanium is that when a low level of DC is passed through it an Oxide will form on the surface of the material. The Oxide will have a color and the density of the color and the shade of the color is dependent on two things. The strength of the DC passing through the Titanium, and, the length of the application of the DC. This change in color is caused by the application of a low level of DC,which alters the surface chemistry. It can only be imagined what happens to both the surface and the matrix of the Titanium when exposed to many thousands of volts DC.
