40 CFR §1030.23

1. (a)For each airplane subject to this part the SAR of an airplane must be determined by either:
   1. (1)Direct flight test measurements; or
   2. (2)Using a performance model that is:
      1. (i)Validated by actual SAR flight test data; and
      2. (ii)Approved by the FAA before any SAR calculations are made.
2. (b)For each airplane model, establish a 1/SAR value at each of the following reference airplane masses:
   1. (1)High gross mass: 92 percent maximum takeoff mass (MTOM).
   2. (2)Low gross mass: (0.45 * MTOM) + (0.63 * (MTOM^0.924)).
   3. (3)Mid gross mass: Simple arithmetic average of high gross mass and low gross mass.
3. (c)Calculate the average of the three 1/SAR values described in paragraph (b) of this section to calculate the fuel efficiency metric value in § 1030.20. Do not include auxiliary power units in any 1/SAR calculation.
4. (d)All determinations under this section must be made according to the procedures applicable to SAR in Paragraphs 2.5 and 2.6 of ICAO Annex 16, Volume III and Appendix 1 of ICAO Annex 16, Volume III (incorporated by reference in § 1030.110).