HAWK MAINTENANCE Army Spc. Tomas Hernandez inspects the tail rotor of a UH-60 Black Hawk helicopter before pilots conduct night flight training on the Aviation Support Facility in Isla Grande, Puerto Rico, Sept. 2, 2014. Hernandez is a crew chief assigned to the Puerto Rico National Guard. SHARE: Download: Full Size (0.04 MB) Credit: VIRIN: 688973-O-OYD67-785.jpg Photo Gallery