A C-17 Globemaster III performs engine running offloads of the Army M1 Abrahms tank at the Geronimo Drop Zone, Fort Polk, Louisiana, during a Joint Expeditionary Forces Exercise (JEFEX). This is the first time that the C-17 has carried a tank and it is also the heaviest load to be delivered to this drop zone. The main objective of the JEFEX is to incorporate Air Force and Army initiatives by employing communications systems that enable information flow between forward deployed and rear elements in a joint environment