(1)
Where appliedloads are eventuallydistributedthrough a single member within an assembly, the failure of which would result in loss of structural integrity of the component; 99percentprobability with95percent con.dence.
(2)
For redundant structure, in which the failure of individual elements would resultin appliedloadsbeing safelydistributedto otherload carrying members; 90 percent probability with 95 percent con.dence.
(c)
The e.ects of temperature on allowable stresses used for design in an essential com-ponent or structure must be considered where thermal e.ects are signi.cant under normal operating conditions.
(d)
The design of the structure must minimize the probability of catastrophic fatigue failure, particularly at points of stress concentration.
(e)
Design values greater than the guaranteed minimums required by this section may beusedwhereonlyguaranteed minimumvaluesarenormally allowedif a ”premium selection” of the material is made in which a specimen of each individual item is testedbefore use todetermine that the actual strengthproperties of thatparticular item will equal or exceed those used in design.]
Amdt. 23-45, E.. 09/07/93
FAR23.615 :[Removed.]
[Removed.] Amdt. 23-45, E.. 09/07/93
FAR23.617 :[Deleted.]
[Deleted.] Amdt. 23-7, E.. 09/14/69
FAR 23.619 : Special factors.
[The factor of safety prescribed in Sec. 23.303 must be multiplied by the highest pertinent specialfactorsof safetyprescribedinSecs.23.621 through23.625foreachpart of the structure whose strength is–
(1) Uncertain :
′
Elodie Roux. Septembre 2003
Subpart D : Design and Construction
(2)
Likely to deteriorate in service before normal replacement; or
(3)
Subject to appreciable variability because of uncertainties in manufacturing pro-cesses or inspection methods.]
Amdt. 23-7, E.. 09/14/69
FAR 23.621 : Casting factors.
(a)
General.Thefactors,tests, andinspections speci.edinparagraphs(b) through(d) of this section must be applied in addition to those necessary to establish foundry qualitycontrol.The inspections must meet approved speci.cations.Paragraphs(c) and (d) of this section apply to any structural castings except castings that are pressure tested as parts of hydraulic or other .uid systems and do not support structural loads.
(b)
Bearing stresses and surfaces.The castingfactorsspeci.edinparagraphs(c) and (d)of this section–
(1)
Need not exceed1.25 with respect to bearing stresses regardless of the method of inspection used; and
(2)
Need notbe used with respecttothebearing surfaces of apart whosebearing factor is larger than the applicable casting factor.
(c)
Critical castings.Foreach casting whosefailurewouldprecludecontinued safe .ight and landing of the airplane or result in serious injury to occupants, the following apply :
(1)
[Eachcritical casting must either–
(i)
Have a casting factor of not less than 1.25 and receive 100 percent ins-pection by visual, radiographic, and either magnetic particle, penetrant or other approved equivalent non-destructiveinspection method; or
(ii)
Have a casting factor of not less than 2.0 and receive 100 percent visual inspection and 100 percent approved non-destructive inspection. When an approved quality control procedure is established and an acceptable statistical analysis supports reduction, non-destructiveinspection maybe reducedfrom100percent, and applied on a sampling basis.]
(2)
For each critical casting with a casting factor less than 1.50, three sample castings must be static tested and shown to meet–
(i)
The strength requirements of Sec. 23.305 at an ultimate load correspon-ding to a casting factor of 1.25; and
(ii) 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 2(23)
