Air Force Inspects Aircraft Barrel Nuts for Cracking

摘要

After five of 13 outer-wing, upper barrel nuts were found cracked on a C-130 Hercules aircraft undergoing routine scheduled maintenance at Warner Robins Air Logistics Center (Robins Air Force Base, Georgia), officials with the U.S. Air Force Materiel Command issued an immediate action timerncompliance technical order in March to inspect all C-130 Hercules aircraft due to potential cracking of wing-joint barrel nuts. The cause of the cracks appears to be hydrogen embrittlement, a process where various metals, particularly high-strength steel, become brittle and crack after being exposed to hydrogen. Source: Air Force Materiel Command Public Affairs.