(a) In projects involving grants-in-aid under the Federal-aid Airport Program, a sponsor must own, acquire, or agree to acquire an adequate property interest in runway clear zone areas as prescribed in paragraph (b), (c), (d), or (e) of this section, as applicable. Property interests that a sponsor acquires to meet the requirements of this section are eligible for inclusion in the Program.

(b) On new airports, the sponsor must own, acquire, or agree to acquire adequate property interests in runway clear zone areas (in connection with initial land acquisition) for all eligible runways or landing strips, without substantial deviation from standard configuration and length.

(c) On existing airports where new runways or landing strips are developed, the sponsor must own, acquire, or agree to acquire adequate property interests in runway clear zone areas for each runway and landing strip to be developed or extended, to the extent that the Administrator determines practical and feasible considering all facts presented by the airport owner or operator, preferably without substantial deviation from standard configuration and length.

(d) On existing airports where improvements are made to runways or landing strips, the sponsor must own, acquire, or agree to acquire adequate property interests in runway clear zone areas for each runway or landing strip that is to be improved to the extent that the Administrator determines is practical and feasible with regard to standard configuration, length, and property interests, considering all facts presented by the airport owner or operator. Any development that improves a specific runway or landing strip is considered to be a runway improvement, including runway lighting and the developing or lighting of taxiways serving a runway.

(e) On existing airports where substantial improvements are made that do not benefit a specific runway or landing strip, such as overall grading or drainage, terminal area or building developments, the sponsor must own, acquire, or agree to acquire adequate property interests in runway clear zone areas for the dominant runway or landing strip to the extent that the Administrator determines is practical and feasible, with regard to standard configuration, length, and property interests, considering all facts presented by the airport owner or operator.

(f) If a sponsor or other public agency shows that it is legally able to prevent the future erection or creation of obstructions in the runway clear zone area, and adopts protective measures to prohibit their future erection or creation, that showing is acceptable for the purposes of paragraphs (d) and (e) of this section in place of an adequate property interest (except for rights required for removing existing obstructions). In such a case, there must be an agreement between the FAA and the sponsor for removing or marking or lighting (to be determined in each case) any existing obstruction to air navigation In each case, the sponsor must furnish information as to the specific height limitations established and as to the current and foreseeable future use of the property to which they apply. The information must include an acceptable legal opinion of the validity of the measures adopted, including a conclusion that the height limitations are not unreasonable in view of current and foreseeable future use of the property, and are a reasonable exercise of the police power, together with the reasons or basis supporting the opinion.

(g) The authority exercised by the Administrator under paragraphs (b), (c), (d), and (e) of this section to allow a deviation from, or the extent of conformity to, standard configuration or length of runway clear zones, or to determine the adequacy of property interests therein, is also exercised by Regional Directors.