14 CFR § 151.43 - United States share of project costs.
(b) Except as provided in paragraphs (c) and (d) of this section and in subpart C of this part, the United States share of the costs of an approved project for airport development (regardless of its size or location) is 50 percent of the allowable costs of the project.
(c) The U.S. share of the costs of an approved project for airport development in a State in which the unappropriated and unreserved public lands and nontaxable Indian lands (individual and tribal) is more than 5 percent of its total land, is the percentage set forth in the following table:
(d) The United States share of the costs of an approved project, representing the costs of any of the following, is 75 percent:
(1) The costs of installing high intensity runway edge lighting on a designated instrument landing runway or other runway with an approved straight-in approach procedure.
(2) The costs of installing in-runway lighting (touchdown zone lighting system, and centerline lighting system).
(3) The costs of installing runway distance markers.
(5) The costs of any project in the Virgin Islands.