US Air Force (USAF) STAFF Sergeant (SSGT) Aaron Crain (foreground), Crewchief, 398th Air Expeditionary Group (AEG), overhauls the Pratt & Whitney TF-33-PW-102 turbofan engine on a USAF NKC-135 "Big Crow", a multi-service electronic countermeasures (ECM) aircraft, at a forward deployed operating base in the Mediterranean region during Operation IRAQI FREEDOM