14 CFR § 151.35 - Airport development and facilities to which subparts B and C apply.
(a) Subparts B and C applies to the following kinds of airport development:
(1) Any work involved in constructing, improving, or repairing a public airport or part thereof, including the constructing, altering, or repairing of only those buildings or parts thereof that are intended to house facilities or activities directly related to the safety of persons at the airport.
(3) Acquiring land or an interest therein, or any easement through or other interest in air space, that is necessary to allow any work covered by paragraph (a)(1) or (2) of this section, or to remove or mitigate, or prevent or limit the establishment of, airport hazards as defined in § 151.39(b).
(2) Required to be located at the airport for use by the users of its aeronautical facilities or by airport operators, concessionaires, and other users of the airport in connection with providing services or commodities to the users of those aeronautical facilities.