Senior Airman Michael Carrubba, 455th Expeditionary Aircraft Maintenance Squadron 83rd Helicopter Maintenance Unit assistant dedicated crew chief, prepares to work on a HH-60 Pave Hawk helicopter on Bagram Air Field, Afghanistan, April 9, 2013. The 83rd HMU's primary mission is to ensure that Bagram's fleet of HH-60 Pave Hawk helicopters are safe and combat-ready so their aircrew and pararescuemen can perform their rescue missions in support of Operation Enduring Freedom. (U.S. Air Force photo/Senior Airman Chris Willis)