(iii) Conditions ”C” and ”F” of (Figure 35.6, p. 453)need onlybe investigated
WW WW
when n3 or n4 are greater than n1 or n2 of this appendix,
SS SS
respectively.
(2) If .apsorotherhighliftdevicesintendedforuseattherelativelylowairspeed of approach,landing,and takeo.,areinstalled,the airplanemustbedesigned for the two .ight conditions corresponding to the values of limit .ap-down factors speci.ed in (Table 35.1, p. 450) of this appendix with the .aps fully extended at notlessthanthedesign .ap speed VFmin from(Figure35.5,p.453) of this appendix.
(c) Unsymmetrical .ight conditions. Each a.ected structure must be designed for un-symmetrical loadings as follows :
(1)
The aft fuselage-to-wing attachment must be designed for the critical vertical surface load determined in accordance with subparagraphs A23.11(c)(1) and (2)of this Appendix.
(2)
The wing and wing carry-through structuresmustbedesignedfor100percent of condition ”A” loading ononesideof theplaneof symmetry and70percent on the opposite side for certi.cation in the normal and utility categories, or 60 percent on the opposite side for certi.cation in the acrobatic category.
(3)
The wing and wing carry-through structures must be designed for the loads resulting from a combination of 75 percent of the positive maneuvering wing loadingonboth sides oftheplane of symmetry and the maximum wingtorsion resultingfrom ailerondisplacement.The e.ect of ailerondisplacement on wing torsion at VC or VA using the basic airfoil moment coe.cient modi.ed over the aileron portion of the span, must be computed as follows :
(i)
Cm = Cm +0.01δu (upaileron side) wing basic airfoil.
(ii)
Cm = Cm .0.01δd (down aileron side)wing basic airfoil, where δu is the up aileron de.ection and δd is the down aileron de.ection.
(4)
Δ critical, which is the sum of δu + δd, must be computed as follows :
(i) Compute Δa and Δb from the formulas :
VA
Δa =Δp, and
VC VA
Δb =0.5Δp
VD
where Δp = the maximum total de.ection (sum of both aileron de.ec-tions) at VA with VA, VC, and VD describedin subparagraph(2) ofSec. 23.7(e) of this appendix.
(ii) Compute K from the formula :
2
(Cm .0.01δb) V
D
K =
2
(Cm .0.01δa) V
C
where δa is the down aileronde.ection corresponding to Δa, and δb is the down aileron de.ection corresponding to Δb as computedin step(i).
(iii) If K is less than 1.0, Δa is Δ critical and must be used to determine δu and δd. In this case, VC is the critical speed which must be used in computing the wing torsion loads over the aileron span.
(iv) If K is equal to or greater than 1.0, Δb is Δ critical and must be used to determine δu and δd. In this case, VD is the critical speed which must be used in computing the wing torsion loads over the aileron span.
(d) Supplementary conditions; rearlifttruss; enginetorque; sideload on engine mount. Each of the following supplementary conditions must be investigated :
(1) In designing the rear lift truss, the special condition speci.ed in Sec. 23.369 may be investigated instead of condition ”G” of (Figure 35.6, p. 453) of this appendix. If this is done, and if certi.cation in more than one category is desired, the value of W used in the formula appearing in Sec. 23.369 must be
S
that for the category corresponding to the maximum gross weight.
′
Elodie Roux. Septembre 2003
Appendix A : Simpli.ed Design Load Criteria
(2)
Each engine mount and its supporting structures must be designed for the maximum limit torque corresponding to METO power and propeller speed acting simultaneously with the limit loads resulting from the maximum po-sitive maneuvering .ight load factor n1. The limit torque must be obtained by multiplying the mean torque by a factor of 1.33 for engines with .ve or more cylinders. For 4, 3, and 2 cylinder engines, the factor must be 2, 3, and 4, respectively.
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 3(9)
