(2)
Dynamic tests simulating actual load application.
FAR 27.307 : Proof of structure
(a)
[Compliance withthe strength anddeformation requirements ofthis subpart mustbe shown for each critical loading condition accounting for the environment to which the structurewillbe exposedin operation.Structural analysis(static orfatigue) maybe used onlyif the structure conforms to those structuresfor which experience has shown this method tobe reliable.In other cases, substantiatingload tests must be made.]
(b)
Proof of compliance with the strength requirements of this subpart must include–
(1)
Dynamic and endurance tests of rotors, rotor drives, and rotor controls;
(2)
Limit load tests of the control system, including control surfaces;
(3)
Operationtests ofthe control system;
(4)
Flight stress measurementtests;
(5)
Landinggeardrop tests; and
(6)
Any additional test required for new or unusual design features. Amdt. 27-26, E.. 4/5/90
′
Elodie Roux. Septembre 2003
Subpart C : Strength Requirements
FAR 27.309 : Design limitations
The following values and limitations must be established to show compliance with the structural requirements of this subpart :
(a)
The design maximum weight.
(b)
The main rotor r.p.m. ranges,power on andpower o..
(c)
The maximumforward speedsforeach main rotorr.p.m. withinthe rangesdetermi-ned underparagraph(b) of this section.
(d)
The maximum rearward and sideward .ight speeds.
(e)
The center of gravity limits corresponding to the limitations determined under pa-ragraphs(b),(c), and(d) of this section.
(f)
The rotational speed ratios between each powerplant and each connected rotating component.
(g)
The positive and negative limit maneuvering load factors.
63.2 Flight Loads
FAR 27.321 : General
(a)
[The .ightloadfactormustbeassumedtoactnormal tothelongitudinal axisof the rotorcraft, and to be equal in magnitude and opposite in direction to the rotorcraft inertialoadfactor atthe center ofgravity.]
(b)
Compliance with the .ight load requirements of this subpart must be shown–
(1)
At each weight from the design minimum weight to the design maximum weight; and
(2)
With any practical distribution of disposable load within the operating limi-tations in the Rotorcraft Flight Manual.
Amdt. 27-11, E.. 2/1/77
FAR 27.337 : Limit maneuvering load factor
[The rotorcraft must be designed for–
(a)
A limit maneuvering load factor ranging from a positive limit of 3.5 to a negative limit of -1.0; or
(b)
Anypositivelimit maneuvering loadfactor notlessthan2.0 and any negativelimit maneuvering load factor of not less than -0.5 for which–
(1)
The probability of being exceeded is shown by analysis and .ight tests to be extremely remote; and
(2)
The selectedvalues are appropriateto each weight conditionbetweenthedesign maximum and design minimum weights.]
Amdt. 27-26, E.. 4/5/90
FAR 27.339 : Resultant limit maneuvering loads
Theloads resultingfromthe application oflimitmaneuveringloadfactors are assumed to actatthe center of each rotorhub[and at each auxiliarylifting surface,] and to actin directions, and with distributions of load among the rotors and auxiliary lifting surfaces, so asto representeach critical maneuvering condition,includingpower-onandpower-o. .ight with the maximum design rotor tip speed ratio. The rotor tip speed ratio is the ratio of the rotorcraft .ight velocity component in the plane of the rotor disc to the rotational tip speed of the rotor blades, and is expressed as follows :
V cosα
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 4(74)
