Text in force at CS25-28: from CS25-1, effective 12 Dec 2005.
(a) The disposable load combinations must include each fuel and oil load in the range from zero fuel and oil to the selected maximum fuel and oil load. A structural reserve fuel condition, not exceeding 45 minutes of fuel under operating conditions in CS 25.1001 (f), may be selected.
(b) If a structural reserve fuel condition is selected, it must be used as the minimum fuel weight condition for showing compliance with the flight load requirements as prescribed in this Subpart. In addition –
(1) The structure must be designed for a condition of zero fuel and oil in the wing at limit loads corresponding to –
(i) A manoeuvring load factor of +2·25; and
(ii) The gust and turbulence conditions of CS 25.341, but assuming 85% of the gust velocities prescribed in CS 25.341(a)(4) and 85% of the turbulence intensities prescribed in CS 25.341(b)(3).
(2) Fatigue evaluation of the structure must account for any increase in operating stresses resulting from the design condition of sub-paragraph (b) (1) of this paragraph; and
(3) The flutter, deformation, and vibration requirements must also be met with zero fuel.
ED Decision 2005/006/R · Source