Under OMB Circular A-126, “Improving the Management and Use of Government Aircraft,” (http://www.whitehouse.gov/omb) GSA's chief responsibilities for Federal aviation management are to maintain -
(a) A single office to carry out Governmentwide responsibilities for Government aircraft management, and publishing that policy;
(b) An interagency committee (i.e., the ICAP), whose members represent the executive agencies that use Government aircraft to conduct their official business (including FAA and NTSB specifically) and advise and consult with GSA on developing policy for managing Government aircraft;
(c) A management information system to collect, analyze, and report information on the inventory, cost, usage, and safety of Government aircraft; and
(d) A set of performance indicators, policy recommendations, and guidance for the procurement, operation, and safety and disposal of Government aircraft.
See OMB Circular A-126 (http://www.whitehouse.gov/omb) for a complete listing of GSA's responsibilities related to Federal aviation.