Why are crack and conductivity standard used?

Question

Why are crack and conductivity standard used?

Answer 1

Certain areas of aircraft are prone to stress cracks, other parts are prone to cracking due to corrosion. The USAF monitors all major structural repairs due to findings during inspections of these areas, usually using Eddy Current testing. This info drives increased or decreased time intervals for particular inspections.

I'm sure our civilian brethren do the same.

Answer 2

If you are referring to tests on the framework and skin of an aircraft,they are done to test the quality of the metal to ensure no hairline cracks have occurred since the last test,,a small current is passed through removed and or isolated sections,,if the output is significantly less then the manufacturers specifications it would suggest metal fatigue ,cracks or imperfections and make the aircraft's airworthiness certificate invalid until repairs were made,,

Answer 3

idk sorry man