; and (6) in section 47136, as so redesignated, by adding at the end the following: (g) Allowable project cost The allowable project cost for the acquisition of a zero-emission vehicle shall be the total cost of purchasing or leasing the vehicle, including the cost of technical assistance or project management support described in subsection (e). (h) Flexible procurement A sponsor of a public-use airport may use funds made available under the program to acquire, by purchase or lease, a zero-emission vehicle and a removable power source in separate transactions, including transactions by which the airport purchases the vehicle and leases the removable power source. (i) Testing required A sponsor of a public-use airport may not use funds made available under the program to acquire a zero-emission vehicle unless that make, model, or type of vehicle has been tested by a Federal vehicle testing facility acceptable to the Secretary. (j) Removable power source defined In this section, the term removable power source means a power source that is separately installed in, and removable from, a zero-emission vehicle and may include a battery, a fuel cell, an ultra-capacitor, or other advanced power source used in a zero-emission vehicle. . (d) Clerical amendment The analysis for chapter 471 of title 49, United States Code, is amended by striking the items relating to sections 47136 and 47136a and inserting the following: 47136. Zero-emission airport vehicles and infrastructure. . 539. Employee Assault Prevention and Response Plans (a) In general Not later than 90 days after the date of enactment of this Act, each air carrier operating under part 121 of title 14, Code of Federal Regulations (in this section referred to as a part 121 air carrier ), shall submit to the Administrator of the Federal Aviation Administration for review and acceptance an Employee Assault Prevention and Response Plan related to the customer service agents of the air carrier and that is developed in consultation with the labor union representing such