Ms. Darlene Costello, a member of the Senior Executive Service, is the Principal Deputy Assistant Secretary of the Air Force Acquisition, Technology & Logistics. Her duties include providing expert advice and guidance on Air Force acquisition programs and procurements. Ms. Costello is also responsible for the development and execution of policies and procedures in support of the operation and improvement of the Air Force’s acquisition system. She oversees an Air Force research and development, test, production and modernization program portfolio of over $40 billion annually.

Ms. Costello has held acquisition positions of increasing responsibility and at all levels of command. Within the Department of the Navy, she held positions as a project engineer, assistant design manager, and program manager. Ms. Costello was then competitively selected for the Commander’s Development Program with assignments in the Office of the Secretary of Defense for Naval Warfare, the Office of the Deputy Assistant Secretary of the Navy (Research, Development, and Acquisition) for Ship Programs, the Office of the Director for Expeditionary Warfare (OPNAV N85) Amphibious Warfare Branch, and the Program Executive Office for Aircraft Carriers.  

In 2000, Ms. Costello moved from the Navy to the Office of the Secretary of Defense, as a staff specialist for Naval Warfare, Strategic and Tactical Systems, within the Office of the Under Secretary of Defense for Acquisition, Technology and Logistics. In 2005, she was appointed to the Senior Executive Service and was promoted to the position of Deputy Director for Naval Warfare, responsible for the oversight of all Naval Warfare acquisition programs including 15 major shipbuilding programs and related weapon systems. 

In 2011, she assumed the duties of the Principal Director for Strategic and Tactical Systems and Director for Acquisition and Program Management. As Principal Director, she was responsible for direct oversight of Major Defense Acquisition Programs for all strategic and tactical systems including the technical and programmatic evaluation of air, land, naval, strategic and unmanned warfare programs. As Director for Acquisition and Program Management, she was responsible for the program management functional area, including policy formulation and initiatives to improve the qualifications and abilities of Department of Defense program managers. In 2013 she became the Acting Deputy Assistant Secretary of Defense for Strategic and Tactical Systems and in 2014 was promoted to the Principal Deputy Assistant Secretary of Defense for Acquisition in the Office of the Under Secretary of Defense for Acquisition, Technology and Logistics. She advised the Under Secretary of Defense (Acquisition, Technology and Logistics), the Deputy Secretary of Defense, and the Secretary of Defense on matters relating to the Department of Defense acquisition system; Major Defense Acquisition Programs; and strategic, space, intelligence, tactical warfare, command and control, and business system acquisitions.