PAYMENTS UNDER GRANT AGREEMENTS.

SEC. 21. PAYMENTS UNDER GRANT AGREEMENTS.The Secretary, after consultation with the sponsor with which a grant agreement has been entered into, may determine the times and amounts in which payments shall be made under the terms of a grant agreement for airport development. Payments in an aggregate amount not to exceed 90 per centum of the United States share of the total estimated allowable project costs may be made from time to time in advance of accomplishment of the airport development to which the payments relate, if the sponsor certifies to the Secretary that the aggregate expenditures to be made from the advance payments will not at any time exceed the cost, of the airport development work which has been performed up to that time. If the Secretary determines that the aggregate amount of payments made under a grant agreement at any time exceeds the United States share of the total allowable project costs, the United States shall be entitled to recover the excess. If the Secretary finds that the airport, development to which the advance payments relate has not been accomplished within a reasonable time or the development is not completed, the United States may recover any part of the advance payment for which the United States received no benefit. Payments under a grant agreement shall be made to the official or depository authorized by law to receive public funds and designated by the sponsor.