This is what is left after a catastrophic bullet burnout. The burnout was determined to be 280 feet up the tower by using a sweep generator  connected at the base. The reflected wave pattern can be analyzed to give the distance to the fault to within a couple of feet over a distance of several hundred feet. We knew a bullet burnout had ocurred as soon as the line was opened up at the base of the tower due to a strong smell of chlorine gas which is released when the bullet's teflon insulator burns up. 

This is the same transmission line opened up 20 feet down at the next flange. There was no burnout here but some debris from the fire landed on the teflon insulator below. The repair was made by removing 4 sections of line and cleaning the outer conductors like a cannon barrel would be cleaned. Three of the center conductors and their bullets were replaced.

This is a burnout that ocurred at the "tee" of an FM antenna array. The burnout was found in this case by a visual inspection. The copper and brass components were discolored by the heat.