architect and engineer services, as authorized by law, unless the Secretary of the Navy determines that additional obligations are necessary for such purposes and notifies the Committees on Appropriations of both Houses of Congress of the determination and the reasons therefor. Military construction, air force For acquisition, construction, installation, and equipment of temporary or permanent public works, military installations, facilities, and real property for the Air Force as currently authorized by law, $1,540,474,000, to remain available until September 30, 2022: Provided , That, of this amount, not to exceed $97,852,000 shall be available for study, planning, design, and architect and engineer services, as authorized by law, unless the Secretary of the Air Force determines that additional obligations are necessary for such purposes and notifies the Committees on Appropriations of both Houses of Congress of the determination and the reasons therefor. Military construction, defense-Wide (including transfer of funds) For acquisition, construction, installation, and equipment of temporary or permanent public works, installations, facilities, and real property for activities and agencies of the Department of Defense (other than the military departments), as currently authorized by law, $2,791,272,000, to remain available until September 30, 2022: Provided , That such amounts of this appropriation as may be determined by the Secretary of Defense may be transferred to such appropriations of the Department of Defense available for military construction or family housing as the Secretary may designate, to be merged with and to be available for the same purposes, and for the same time period, as the appropriation or fund to which transferred: Provided further , That, of the amount, not to exceed $185,717,000 shall be available for study, planning, design, and architect and engineer services, as authorized by law, unless the Secretary of Defense determines that additional obligations are necessary for such purposes