(7)
The compression load measured between the pelvis and the lumbar spine of the ATD may not exceed 1,500 pounds.
(d) [For allsingle-engine airplanes with a VS0 of morethan61knots at maximum weight, and those multiengine airplanes of 6,000 pounds or less maximum weight with a VS0 of more than 61 knots at maximum weight that do not comply with Sec. 23.67(a)(1);]
(1)
The ultimate load factors of Sec. 23.561(b) must be increased by multiplying the load factors by the square of the ratio of the increased stall speed to 61 knots. The increased ultimate load factors need not exceed the values reached at a VS0 of 79 knots. The upward ultimate load factor for acrobatic category airplanes need not exceed 5.0 g.
(2)
The seat/restraint system test required by paragraph (b)(1) of this section must be conducted in accordance with the following criteria :
(i) The change in velocity may not be less than 31 feet per second.
′
Elodie Roux. Septembre 2003
Subpart C : Structure
(ii) (A) The peak deceleration(gρ) of 19g and 15g must be increased and multiplied by the square of the ratio of the increased stall speed to 61 knots :
VS02 gρ = 19.0
61
VS02 or gρ = 15.0
61
(B) Thepeakdecelerationneed not exceed the value reached at a VS0 of 79 knots.
(iii) The peak deceleration must occur in not more than time (tγ), which must be computed as follows :
31 0.96
tγ ==
32.2gρ gρ
where– gρ :The peak deceleration calculated in accordance with para-graph(d)(2)(ii) of this section; and tγ :The risetime(in seconds) tothepeakdeceleration.
(e) An alternate approach that achieves an equivalent, or greater, level of occupant protectiontothatrequiredbythis section maybe usedif substantiated on a rational basis.
Amdt. 23-50, E.. 03/11/96
30.10 Fatigue Evaluation
FAR23.571 :[Metallicpressurized cabin structures.]
[Fornormal,utility, andacrobaticcategory airplanes,thestrength,detaildesign,and fabrication of the metallic structure of the pressure cabin must be evaluated under one of the following :
(a)
A fatigue strength investigation in which the structure is shown by tests, or by analysis supported by test evidence, to be able to withstand the repeated loads of variable magnitude expected in service; or]
(b)
A fail safe strength investigation, in which it is shown by analysis, tests, or both that catastrophic failure of the structure is not probable after fatigue failure, or obvious partial failure, of a principal structural element, and that the remaining structures are able to withstand a static ultimate load factor of 75 percent of the limit load factor at VC, considering the combined e.ects of normal operating pressures, expected external aerodynamic pressures, and .ight loads. These loads must be multiplied by a factor of 1.15 unless the dynamic e.ect of failure under static load are otherwise considered.
(c)
The damage tolerance evaluation of Sec. 23.573(b). Amdt. 23-48, E.. 03/11/96
FAR23.572 :[Metallic] wing, empennage, and associated structures.
(a)
[For normal, utility, and acrobatic category airplanes, the strength, detail design, and fabrication of those parts of the airframe structure whose failure would be catastrophic must be evaluated under one of the following unless it is shown that the structure, operating stress level, materials and expected uses are comparable, from a fatigue standpoint, to a similar design that has had extensive satisfactory service experience :
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本文鏈接地址：FAA規(guī)章 美國(guó)聯(lián)邦航空規(guī)章 Federal Aviation Regulations 2(18)
