; to be derived from the Airport and Airway Trust Fund, $3,005,000,000, of which $498,000,000 shall remain available until September 30, 2019, $2,392,000,000 shall remain available until September 30, 2020, and $115,000,000 shall remain available until expended: Provided , That there may be credited to this appropriation funds received from States, counties, municipalities, other public authorities, and private sources, for expenses incurred in the establishment, improvement, and modernization of national airspace systems: Provided further , That none of the funds made available in this Act or any other Act shall be used to plan or implement the liquidation of the FAA’s federally-owned assets, or the intellectual property rights of the air traffic organization: Provided further , That no later than March 31, the Secretary of Transportation shall transmit to the Congress an investment plan for the Federal Aviation Administration which includes funding for each budget line item for fiscal years 2019 through 2023, with total funding for each year of the plan constrained to the funding targets for those years as estimated and approved by the Office of Management and Budget. Research, engineering, and development (airport and airway trust fund) For necessary expenses, not otherwise provided for, for research, engineering, and development, as authorized under part A of subtitle VII of title 49, United States Code, including construction of experimental facilities and acquisition of necessary sites by lease or grant, $179,000,000, to be derived from the Airport and Airway Trust Fund and to remain available until September 30, 2020: Provided , That there may be credited to this appropriation as offsetting collections, funds received from States, counties, municipalities, other public authorities, and private sources, which shall be available for expenses incurred for research, engineering, and development. Grants-in-aid for airports (liquidation of contract authorization) (limitation on obligations) (airport and airway