FAR 23.337 : Limit maneuvering load factors.
24000
Amdt. 23-48, E.. 03/11/96
FAR 23.341 : Gust load factors.
(a)
[Eachairplane must be designed to withstand loads on each lifting surface resulting from gusts speci.ed in Sec. 23.333(c).
(b)
The gust load for a canard or tandem wing con.guration must be computed using a rational analysis, or maybe computedin accordance withparagraph(c) ofthis 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–]
Kg Ude Va
n =1+
498 W
S
where-
Kg :gust alleviation factor Kg =0.88μg + μg ;
5.3
(W/S)
μg :Airplane mass ratio μg =2C ag
ρ
Ude :Derived gust velocities referred to in Sec. (f.p.s.); 23.333(c) ρ :Density of air (slugs/cu.ft.);
W
:[wing loading (p.s.f.) due to the applicable
S
weight of the airplane in the particular load
case.] C :Meangeometricchord (ft.); g :Accelerationduetogravity (ft./sec.2); V :airplane equivalent speed (knots); a :Slope of the airplane normal force coe.cient
curve CNA per radian if the gust loads are applied to the wings and horizontal tail sur-faces 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. 23-48, E.. 03/11/96
FAR23.343 :[Designfuelloads.]
(a)
[The disposable load combinations must include each fuel load in the range from zero fuel to the selected maximum fuel load.
(b)
Iffuel is carriedin the wings, the maximum allowable weightof the airplane without any fuel in the wing tank(s) must be established as ”maximum zero wing fuel weight,” if it is less than the maximum weight.
(c)
For commuter category airplanes, a structural reserve fuel condition, not exceeding fuel necessary for 45 minutes of operation at maximum continuous power, may be selected. If a structural reserve fuel condition is selected, it must be used as the minimum fuel weight condition for showing compliance with the .ight load requirementsprescribedinthispart and–
′
Elodie Roux. Septembre 2003
Subpart C : Structure
(1)
The structure must be designed to withstand a condition of zero fuel in the wing at limit loads corresponding to :
(i)
Ninetypercent of the maneuveringloadfactorsde.nedinSec.23.337, and
(ii)
Gustvelocities equalto85percent ofthe valuesprescribedinSec.23.333(c).
(2)
The fatigue evaluation of the structure must account for any increase in ope-rating stresses resulting fromthedesign condition ofparagraph(c)(1) of this section.
(3)
The .utter, deformation, and vibration requirements must also be met with zero fuel in the wings.]
