The Under Secretary of the Air Force (USECAF, or SAF/US), sometimes referred to as the Under Secretary of the Department of the Air Force, is the second-highest ranking civilian official in the Department of the Air Force of the United States of America, serving directly under the Secretary of the Air Force. In the absence of the Secretary, the Under Secretary exercises all the powers and duties of the Secretary and serves as Acting Secretary when the position of Secretary is vacant. The Under Secretary of the Air Force is appointed by the President, by and with the advice and consent of the Senate.