German Air Force (Luftwaffe) maintenance technicians troubleshoot a problem on a GR-4 Tornado fighter-bomber aircraft before it takes off from Eielson Air Force Base (AFB), Alaska (AK), for a training mission during Exercise COOPERATIVE COPE THUNDER, the largest multinational air combat training exercise in the Pacific. This 15-day exercise simulates wartime combat conditions so that military personnel from 12-nations can sharpen their air fighting skills, exchange air operational tactics, and build closer relations with each other