.
Apositive value of K indicates a moment tending to depress the surface, while a negative value of K indicates a moment tending to raise the surface.
Amdt. 25-91, E.. 7/29/97
FAR 25.427 : Unsymmetrical loads.
(a)
[In designingthe airplane for lateral gust, yaw maneuver and roll maneuver condi-tions, account mustbe taken of unsymmetricalloads on the empennage arisingfrom e.ects such as slipstream and aerodynamic interference with the wing, vertical .n and other aerodynamic surfaces.
(b)
The horizontal tail must be assumed to be subjected to unsymmetrical loading conditions determined as follows :
(1)
100 percent of the maximum loading from the symmetrical maneuver condi-tions of Sec. 25.331 and the vertical gust conditions of Sec. 25.341(a) acting separately on the surface on one side of the plane of symmetry; and
(2)
80 percent of these loadings acting on the other side.
(c)
Forempennagearrangementswherethehorizontal tail surfaceshavedihedral angles greater thanplus or minus10degrees, or are supportedbythe verticaltail surfaces, the surfaces and the supporting structure mustbedesignedforgust velocities spe-ci.ed in Sec. 25.341(a) acting in any orientation at right angles to the .ight path.
(d)
Unsymmetrical loading on the empennage arising from bu.et conditions of Sec. 25.305(e) must be taken into account.]
Amdt. 25-86, E.. 3/11/96
′
Elodie Roux. Septembre 2003
Subpart C : Structure
FAR25.445 :[Auxiliary aerodynamic surfaces.]
(a)
[When signi.cant, the aerodynamic in.uence between auxiliary aerodynamic sur-faces, such as outboard .ns and winglets, and their supporting aerodynamic sur-faces, mustbe takeninto accountfor allloadingconditionsincludingpitch, roll, and yaw maneuvers, and gusts as speci.ed in Sec. 25.341(a) acting at any orientation at right angles to the .ight path.]
(b)
To provide for unsymmetrical loading when outboard .ns extend above and below the horizontal surface, the critical vertical surface loading (load per unit area) determined under Sec. 25.391 must also be applied as follows :
(1) 100percent to the area of the vertical surfaces above(or below) the horizontal surface.
(2)
80percenttothe areabelow(or above) thehorizontal surface. Amdt. 25-86, E.. 3/11/96
FAR 25.457 : Wing .aps.
Wing .aps, their operating mechanisms, and their supporting structures must be designedfor criticalloads occurringinthe conditionsprescribedinSec.25.345,accounting fortheloadsoccurringduring transitionfromone .appositionand airspeed toanother.
FAR 25.459 : Special devices.
Theloadingfor specialdevices using aerodynamic surfaces(such as slots[, slats,] and spoilers) must be determined from test data. Amdt. 25-72, E.. 8/20/90
46.6 Ground Loads
FAR 25.471 : General.
(a)
Loads and equilibrium. For limit ground loads–
(1)
Limit ground loads obtained under this subpart are considered to be external forces appliedtothe airplane structure; and
(2)
In each speci.ed ground load condition, the external loads must be placed in equilibrium with the linear and angular inertia loads in a rational or conser-vative manner.
(b)
[Critical centers ofgravity. The critical centers ofgravity within the rangefor which certi.cation is requested must be selected so that the maximum design loads are obtained in each landing gear element. Fore and aft, vertical, and lateral airplane centers of gravity must be considered. Lateral displacements of the c.g. from the airplane centerline which would result in main gear loads not greater than 103 percent of the critical design load for symmetrical loading conditions may be selec-ted without considering the e.ects of theselateral c.g.displacements on theloading of the main gear elements, or on the airplane structure provided–
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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(55)
