(b) Whenever the project is completed in accordance with the grant agreement, the sponsor may apply for final payment. The final payment is made to the sponsor if—
(1) A final inspection of all work at the airport site has been made jointly by the Area Manager and representatives of the sponsor and the contractor, unless the Area Manager agrees to a different procedure for final inspection.
(2) A final audit of the project account has been completed by appropriate personnel of the FAA; and
(3) The sponsor has furnished final “as constructed” plans, unless otherwise agreed to by the Administrator.
(c) Based upon the final inspection, the final audit, the plans, and the documents and supporting information required by §151.57(a), the Administrator determines the total amount of the allowable project costs and pays the sponsor the United States' share, less the total amount of all prior payments.