(a) The United States' share of advance planning costs is paid in two installments unless the advance planning grant agreement provides otherwise. Upon request by sponsor, the first payment may be made in an amount not more than 50 percent of the maximum obligation of the United States stipulated in the advance planning grant agreement upon certification by sponsor that 50 percent or more of the proposed work has been completed. The final payment is made upon the sponsor's request after—

1. (1) The conditions of the advance planning grant agreement have been met;
2. (2) Evidence of cost of each item has been submitted; and
3. (3) Audit of submitted evidence or audit of sponsor's records, if considered desirable by FAA, has been made.