(b)
If there is a swivel, the tail wheel is assumed to be swiveled 90'to the airplane longitudinal axis withthe resultantloadpassing through the axle.
(c)
If there is a lock, steering device, or shimmy damper the tail wheel is also assumed tobeinthetrailingposition with the sideload acting attheground contactpoint.
FAR25.499:[Nose-wheelyaw andsteering.]
(a)
A vertical load factor of 1.0 at the airplane center of gravity, and a side component at the nose wheel ground contact equal to 0.8 of the vertical ground reaction at that point are assumed.
(b)
With the airplane assumed to be in static equilibrium with the loads resulting from the use of brakes on one side of the main landing gear, the nose gear, its atta-ching structure, and the fuselage structureforward of the center ofgravity must be designed for the following loads :
(1)
A vertical load factor at the center of gravity of 1.0.
(2)
A forward actingload at the airplane center ofgravity of0.8 times the vertical load on one main gear.
′
Elodie Roux. Septembre 2003
Subpart C : Structure
(3)
Side and vertical loads at the ground contact point on the nose gear that are required for static equilibrium.
(4)
A side load factor at the airplane center of gravity of zero.
(c)
If theloadsprescribedinparagraph(b) of this sectionresultin anosegearsideload higher than 0.8 times the vertical nose gear load, the design nose gear side load may be limited to 0.8 times the vertical load, with unbalanced yawing moments assumed to be resisted by airplane inertia forces.
(d)
For other than the nosegear,its attaching structure, and the forwardfuselage struc-ture, theloading conditions arethoseprescribedinparagraph(b) of this section, except that–
(1)
A lower drag reaction may be used if an e.ective drag force of 0.8 times the vertical reaction cannot be reached under any likely loading condition; and
(2)
Theforwardactingload at the center ofgravity need not exceed the maximum dragreaction on one maingear,determinedin accordance withSec.25.493(b).
(e)
[Withthe airplane atdesign rampweight, andthe nosegearin any steerableposition, the combined application of full normal steering torque and vertical force equal to
1.33 times the maximum static reaction on the nose gear must be considered in designingthe nosegear,its attachingstructure, andtheforwardfuselage structure.]
Amdt. 25-91, E.. 7/29/97
FAR 25.503 : Pivoting.
(a)
The airplane is assumed to pivot about one side of the main gear with the brakes on that side locked. The limit vertical load factor must be 1.0 and the coe.cient of friction 0.8.
(b)
The airplane is assumed to be in static equilibrium, with the loads being applied at the ground contact points, in accordance with .gure 8 of Appendix A.
FAR 25.507 : Reversed braking.
(a)
The airplane must be in a three point static ground attitude. Horizontal reactions parallel totheground anddirectedforward mustbe applied attheground contact point of each wheel with brakes. The limit loads must be equal to 0.55 times the vertical load at each wheel or to the load developed by 1.2 times the nominal maximum static brake torque, whichever is less.
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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(59)
