U.S. Airmen assigned to the 633rd Medical Group prepare for briefings and initial evaluations upon their return to Langley Air Force Base, Va., Oct. 20, 2014, from a nearly one-month deployment to West Africa during Operation United Assistance. None of the Airmen exhibited symptoms of the Ebola virus, and all were considered to have no known exposure to the disease. United Assistance is a Department of Defense operation to provide command and control, logistics, training and engineering support to U.S. Agency for International Development-led efforts to contain the Ebola virus outbreak in West African nations.