Code of Federal Regulations Title 40. Protection of Environment § 40.1030.35 Change criteria

(a) For an airplane that has demonstrated compliance with § 1030.30, any subsequent version of that airplane must demonstrate compliance with § 1030.30 if the subsequent version incorporates a modification that either increases—

(b) For an airplane that has demonstrated compliance with § 1030.30, any subsequent version of that airplane that incorporates modifications that do not increase the MTOM or the fuel efficiency metric value in excess of the levels shown in paragraph (a) of this section, the fuel efficiency metric value of the modified airplane may be reported to be the same as the value of the prior version.

(c) For an airplane that meets the criteria of § 1030.1(a)(4) or (5), after January 1, 2023 and until January 1, 2028, the airplane must demonstrate compliance with § 1030.30 if it incorporates any modification that increases the fuel efficiency metric value by more than 1.5 per cent from the prior version of the airplane.