; and (2) compliance with the requirements of this section does not— (A) impact the safety or security of flight or the operation of an aircraft in flight or on the ground; or (B) require the air carrier employer to incur significant expense, such as through the addition of a crewmember in response to providing a break described in subsection (a)(1) to another crewmember, removal or retrofitting of seats, or the modification or retrofitting of an aircraft. (c) Significant expense For purposes of subsection (b)(2)(B), modifying or retrofitting an aircraft by installing a curtain or other screening protection shall not be considered a significant expense. 4. Antiretaliation It shall be unlawful for any person to discharge or in any other manner discriminate against any employee because such employee has— (1) filed any complaint or instituted or caused to be instituted any proceeding under or related to this Act; or (2) testified or is about to testify in any such proceeding. 5. Rulemaking Not later than 3 years after the date of enactment of this section, the Administrator of the Federal Aviation Administration, in consultation with the Secretary of Labor, shall issue regulations, as appropriate, to define and delimit the terms and conditions under section 3 for all crewmember time onboard an aircraft. 6. Remedies (a) Enforcement by the Secretary (1) In general The Secretary of Labor shall receive, investigate, and attempt to resolve complaints of violations of sections 3 and 4 in the same manner that the Secretary of Labor receives, investigates, and attempts to resolve complaints of violations of section 18D and 15A(3) of the Fair Labor Standards Act of 1938 ( 29 U.S.C. 218d ). (2) Violations of section 3 An air carrier employer that violates section 3 shall— (A) be considered to be in violation of section 18D of the Fair Labor Standards Act of 1938 ( 29 U.S.C. 218d ; 29 U.S.C. 215(a)(3) ); and (B) be subject to the penalties described in sections 16 and 17 of such Act ( 29 U.S.C. 216