Read Consulting failure analysis lab performed a glass failure analysis on a failed aircraft windshield. The windshield of a turbo-prop aircraft suddenly cracked during descent through clouds. Initially it was thought that static electricity had caused the glass failure. Initially it was proposed that the static electricity sought the aircraft “ground” through heating wires in the windshield. The failure analysis determined that the failure was caused by impact to the outer layer of the windshield. This is demonstrated by the crushed glass at the origin and the subsurface conchoidal fracture around the origin. The flight was in icy conditions; it is possible that a piece of ice came off the propeller and impacted the windshield.