by helicopter or fixed-wing aircraft— (1) such exemption shall also apply to powered-lift aircraft (as defined in section 4261(l) of such Code (as added by this section), and (2) such Secretary (or delegate) shall modify such regulation or other guidance consistent with the purposes of paragraph (1). (e) Effective date (1) In general The amendments made by this section shall take effect on the first day of the first calendar quarter beginning more than 60 days after the date of the enactment of this Act. (2) Regulatory exemptions Subsection (d) shall take effect as if such subsection were an amendment to which paragraph (1) applies.