U.S. Airmen assigned to the 633rd Medical Group board a C-17 Globemaster III aircraft at Joint Base Langley-Eustis, Va., Sept. 26, 2014. The aircraft was scheduled to fly to Monrovia, Liberia, carrying a modular medical treatment center and supplies in support of Operation United Assistance. United Assistance is a U.S. Africa Command-led operation to provide command and control, logistics, training and engineering support to the U.S. government's efforts to contain the Ebola virus outbreak in West African nations.