(a) Each airplane must be designed to withstand loads on each lifting surface resulting from gusts specified in Sec. 23.333(c).
(b) The gust load for a canard or tandem wing configuration must be computed using a rational analysis, or may be computed in accordance with paragraph (c) of this section, provided that the resulting net loads are shown to be conservative with respect to the gust criteria of Sec. 23.333(c).
(c) In the absence of a more rational analysis, the gust load factors must be computed as follows--[GRAPHIC] [TIFF OMITTED] TR09FE96.010 Where-- Kg=0.88[micro]g/5.3+[micro]g=gust alleviation
factor;[micro]g=2(W/S)/[rho] Cag=airplane mass ratio;Ude=Derived gust velocities referred to in Sec. 23.333(c) (f.p.s.);[rho]=Density of air (slugs/cu.ft.);W/S=Wing loading (p.s.f.) due to the applicable weight of the airplane
in the particular load case.W/S=Wing loading (p.s.f.);C=Mean geometric chord (ft.);g=Acceleration due to gravity (ft./sec.\2\)V=Airplane equivalent speed (knots); anda=Slope of the airplane normal force coefficient curve CNA per radian if
the gust loads are applied to the wings and horizontal tail
surfaces simultaneously by a rational method. The wing lift
curve slope CL per radian may be used when the gust load is
applied to the wings only and the horizontal tail gust loads
are treated as a separate condition. [Amdt. 23-7, 34 FR 13088, Aug. 13, 1969, as amended by Amdt. 23-42, 56 FR 352, Jan. 3, 1991; Amdt. 23-48, 61 FR 5144, Feb. 9, 1996]