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Elodie Roux. Septembre 2003
Subpart C : Structure
This must be shown by analysis, .ight tests, or other tests found necessary by the Administrator.
(f) Unless shown to be extremely improbable, the airplane must be designed to withs-tand any forced structural vibration resulting from any failure, malfunction or ad-verse condition in the .ight control system. These must be considered limit loads and must be investigated at airspeeds up to VC/MC.
Amdt. 25-86, E.. 3/11/96
FAR 25.307 : Proof of structure.
(a)
Compliance with the strength and deformation requirements of this subpart must be shown for each critical loading condition. Structural analysis may be used only if the structure conforms to those for which experience has shown this method to bereliable.TheAdministratormay requireultimateload testsin caseswherelimit load tests may be inadequate.
(b)
[Reserved.]
(c)
[Reserved.]
(d)
When static or dynamic tests are used to show compliance with the requirements of Sec. 25.305(b)for .ight structures, appropriate material correction factors must be applied to the test results, unless the structure, or part thereof, being tested has features such that a number of elements contribute to the total strength of the structure and the failure of one element results in the redistribution of the load through alternate load paths.
Amdt. 25-72, E.. 8/20/90
46.2 Flight Loads
FAR 25.321 : General.
(a)
Flightloadfactors representthe ratio ofthe aerodynamicforce component(acting normal to the assumed longitudinal axis of the airplane) to the weight of the air-plane. A positive load factor is one in which the aerodynamic force acts upward with respect to the airplane.
(b)
Considering compressibility e.ects at each speed, compliance with the .ight load requirements of this subpart must be shown–
(1)
At each critical altitude within the range of altitudes selectedby the applicant;
(2)
Ateach weightfromthedesign minimum weighttothedesign maximum weight appropriatetoeachparticular .ightload condition; and
(3)
For each required altitude and weight, for any practicable distribution of dis-posable load within the operating limitations recorded in the Airplane Flight Manual.
(c)
[Enough points on andwithin the boundaries of the design envelope must be inves-tigated to ensurethatthe maximumloadfor eachpart of the airplane structureis obtained.
(d)
The signi.cant forces acting on the airplane must be placed in equilibrium in a rational or conservative manner. The linear inertia forces must be considered in
equilibrium with the thrust and all aerodynamicloads, while the angular(pitching) inertia forces must be considered in equilibrium with thrust and all aerodynamic moments, including moments due to loads on components such as tail surfaces and nacelles. Critical thrust values in the range from zero to maximum continuous thrust must be considered.]
Amdt. 25-86, E.. 3/11/96
46.3 Flight Maneuver and Gust Conditions
FAR 25.331 : Symmetric maneuvering conditions.
(a)
Procedure. For the analysis of the maneuvering .ight conditions speci.ed in para-graphs(b) and(c) of this section,thefollowingprovisions apply :
(1)
Where suddendisplacementof a controlis speci.ed,the assumed rate of control surface displacement may not be less than the rate that could be applied by the pilot through the control system.
(2)
In determining elevator angles and chordwise load distribution in the ma-neuvering conditions ofparagraphs(b) and(c) ofthis section,the e.ect of correspondingpitching velocities mustbe takeninto account.Thein-trim and out-of-trim .ight conditions speci.ed in Sec. 25.255 must be considered.
(b)
Maneuvering balanced conditions. Assuming the airplane to be in equilibrium with zeropitching acceleration,the maneuvering conditionsA throughI onthe maneu-vering envelope in Sec. 25.333(b) must be investigated.
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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(45)
