; (4) in subsection (d), by striking subsection (b)(2) and inserting subsection (b)(3) ; (5) in subsection (h), by striking subsection (b)(2) and inserting subsection (b)(3) ; and (6) in subsection (k), by striking subsection (b)(2) and inserting subsection (b)(3) . (b) Definitions Section 47175 of title 49, United States Code, is amended by adding at the end the following: (8) General aviation airport construction or improvement project The term general aviation airport construction or improvement project means— (A) a project for the construction or extension of a runway, including any land acquisition, helipad, taxiway, safety area, apron, or navigational aids associated with the runway or runway extension, at a general aviation airport, a reliever airport, or a commercial service airport that is not a primary airport (as such terms are defined in section 47102); and (B) any other airport development project that the Secretary designates as facilitating aviation capacity building projects at a general aviation airport. . 192. Zero-emission vehicles and technology (a) In general Section 47136 of title 49, United States Code, as so redesignated, is amended— (1) by striking subsections (a) and (b) and inserting the following: (a) In general The Secretary of Transportation may establish a pilot program under which the sponsors of public-use airports may use funds made available under this chapter or section 48103 for use at such airports to carry out— (1) activities associated with the acquisition, by purchase or lease, and operation of eligible zero-emission vehicles and equipment, including removable power sources for such vehicles; and (2) the construction or modification of infrastructure to facilitate the delivery of fuel, power or services necessary for the use of such vehicles. (b) Eligibility A public-use airport is eligible for participation in the program if the eligible vehicles or equipment are— (1) used exclusively on airport property