(c)
Evaluations shall be made of the following :
(1)
The e.ects on vibration characteristics of operating with scheduled changes (including tolerances) to variable vane angles, compressor bleeds, accessory loading, the most adverse inlet air .ow distortion pattern declared by the manufacturer, and the most adverse conditionsinthe exhaustduct(s); and
(2)
The aerodynamic and aeromechanical factors which might induce or in.uence .utter in those systems susceptible to that form of vibration.
(d)
Except asprovidedbyparagraph(e) ofthis section, the vibration stresses associated with the vibration characteristics determined under this section, when combined with the appropriate steady stresses, must be less than the endurance limits of the materials concerned, after making due allowances for operating conditions for the permitted variations in properties of the materials. The suitability of these stress margins must be justi.ed for each part evaluated. If it is determined that cer-tain operating conditions, or ranges, need to be limited, operating and installation limitations shall be established.
(e)
The e.ects on vibration characteristics ofexcitationforces causedbyfault conditions (suchas,but notlimited to, out-ofbalance,localblockageorenlargement of stator
vanepassages,fuel nozzleblockage,incorrectly schedule compressor variables, etc.) shall be evaluated by test or analysis, or by reference to previous experience and shall be shown not to create a hazardous condition.
(f) Compliance with this section shall be substantiated for each speci.c installation con.guration that can a.ect the vibration characteristics of the engine. If these vi-bration e.ects cannotbefullyinvestigatedduring engine certi.cation, the methods by which they can be evaluated and methods by which compliance can be shown shall be substantiated and de.ned in the installation instructions required by Sec. 33.5.]
Amdt. 33-17, E.. 7/5/96
FAR 33.85 : Calibration tests.
(a)
Each engine must be subjected to those calibration tests necessary to establish its power characteristics andthe conditionsfor the endurance test speci.edSec.33.87. The results of the power characteristics calibration tests form the basis for esta-blishing the characteristics of the engine over its entire operating range of speeds, pressures, temperatures, and altitudes. Power ratings are based upon standard at-mospheric conditions with no airbleed for aircraft services and with only those accessories installed which are essential for engine functioning.
(b)
A power check at sea level conditions must be accomplished on the endurance test engine after the endurance test and any change in power characteristics which occurs during the endurance test must be determined. Measurements taken during the .nal portion of the endurance test may be used in showing compliance with the requirement of this paragraph.
(c)
[In showingcompliance with this section, each condition must stabilize before mea-surements aretaken, except aspermittedbyparagraph(d) of this section.
(d)
In the case of engines having 30-second OEI, and 2-minute OEI ratings, measure-ments taken during the applicable endurance test prescribed in Sec. 33.87(f)(1) through(8) may be usedin showing compliance withthe requirements of this sec-tion for these OEI ratings.]
Amdt. 33-18, E.. 8/19/96
FAR 33.87 : Endurance test.
(a) General.[Each engine must be subjected to an endurance test that includes a total of at least 150 hours of operation and, depending upon the type and contemplated use of the engine, consists of one of the series of runs speci.edinparagraphs(b) through(g) of this section, as applicable.For enginestested underparagraphs(b), (c), (d), (e) or (g) of this section, the prescribed 6-hour test sequence must be conducted 25 times to complete the required 150 hours of operation. Engines for which the 30-second OEI and 2-minute OEI ratings are desired must be further tested underparagraph(f) of this section.Thefollowing test requirementsapply :]
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 5(143)
