For each airplane subject to this part, or to determine whether a modification makes an airplane subject to this part under the change criteria of § 38.19, a fuel efficiency metric value must be calculated, using the following equation, rounded to three decimal places:
Where:
The SAR is determined in accordance with § 38.13, and the RGF is determined in accordance with § 38.15. The fuel efficiency metric value is expressed in units of kilograms of fuel consumed per kilometer.
source: Docket No. FAA-2022-0241, Amdt. No. 21-107, 89 FR 12654, Feb. 16, 2024, unless otherwise noted.
cite as: 14 CFR 38.11