(2)
For eachofthe missionsegmentsde.ned underparagraph(c)(1) ofthis ap-ˉ
pendix, values of Aˉand No must be determined by analysis. A is de.ned as the ratio of root-mean-square incremental load to root-mean-square gust velocity and No is the radius of gyration of the load power spectral density function aboutzerofrequency.Thepowerspectraldensity of the atmospheric turbulencemustbegivenby theequationsetforthinparagraph(b)(2) of this appendix.
(3)
For each of the load and stressquantities selected, thefrequency of exceedance must be determined as a function of load level by means of the equation-
|y.yone=g||y.yone=g|
N(y)= tNo P1 exp + P2 exp
ˉˉ
b1 Ab2 A
where– t : selected time interval.
y : net value of the load or stress. yone=g : value of the load or stress in one-g level .ight.
N(y) :averagenumberof exceedancesof theindicated valueof the load or stress in unit time.
: symbol denoting summation over all mission segments. No,Aˉ: parameters determined by dynamic analysis as de.ned in paragraph(c)(2) of this appendix.
P1,P2,b1,b2 : parameters de.ning the probability distributions of root-mean-squaregust velocity,tobe readfromFigures1 and2 of this appendix.
Thelimitgustloads mustbe readfromthefrequency of exceedancecurvesat afrequency of exceedance of210.5 exceedances per hour. Both positive and negative load directions must be considered in determining the limit loads.
(4) If a stability augmentation system is utilized to reduce the gust loads, consi-deration must be given to the fraction of .ight time that the system may beinoperative.The .ightpro.lesofparagraph(c)(1) ofthisappendixmust include .ight with the system inoperative for this fraction of the .ight time. When a stability augmentation system is included in the analysis, the e.ect of system nonlinearities on loads at the limit loadlevel mustbe conservatively accounted for.
(d) Supplementary design envelope analysis. In addition to the limit loads de.ned by paragraph(c) of this appendix,limitloads must alsobedeterminedin accordance withparagraph(b) of this appendix, exceptthat–
(1)
Inparagraph(b)(3)(i) ofthis appendix,the value of Uσ = 85 fps true gust velocity is replaced by Uσ = 60 fps true gust velocity on the interval 0 to 30,000 ft. altitude, and is linearly decreased to 25 fps true gust velocity at 80,000ft. altitude; and
(2)
Inparagraph(b)ofthis appendix,the referencetoparagraphs(b)(3)(i)through (b)(3)(iii) of this appendix is to be understood as referring to the paragraph as modi.edbyparagraph(d)(1).
] Amdt. 25-54, E.. 10/14/80
′
Elodie Roux. Septembre 2003
Appendix G
Chapitre 58 Appendix H
Sommaire
FAR25.H1:[AirworthinessLimitationssection.] . . . . . . . 764 FAR25.H2:[Format.] ..................... 764 FAR25.H3:[Content.] ..................... 764 FAR 25.H4 : Airworthiness Limitations section. . . . . . . . 765
763
Appendix H
FAR25.H1 :[AirworthinessLimitations section.]
The Instructions for Continued Airworthiness must contain a section titled Airwor-thiness Limitations that is segregated and clearly distinguishable from the rest of the document. This section must set forth each mandatory replacement time, structural ins-pectioninterval, andrelated structuralinspectionprocedure approved underSec.25.571. If the Instructions for Continued Airworthiness consist of multiple documents, the sec-tion required by this paragraph must be included in the principal manual. This section must containalegiblestatementinaprominentlocationthat reads: ”TheAirworthiness Limitations sectionisFAA approved and speci.es underSecs.43.16 and[91.403] ofthe FederalAviationRegulations unless an alternativeprogramhasbeenFAA approved. Amdt. 25-68, E.. 8/18/90
FAR25.H2 :[Format.]
(a)
[The Instructions for Continued Airworthiness must be in the form ofa manual or manuals as appropriate for the quantity of data to be provided.
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