(3)
For turbine enginepoweredairplanes,if the minimum windmilling speed of the engines,following thein.ight shutdown of all engines,isinsu.cient toprovide the necessary electricalpowerfor engineignition,apowersourceindependent of the engine-driven electrical power generating system must be provided to permit in.ight engine ignition for restarting.
(f)
Auxiliary Power Unit. Each auxiliary power unit must be approved or meet the requirements of the category for its intended use.
Amdt. 25-100, E.. 12/13/2000
FAR25.904:[Automatictakeo.thrust control system(ATTCS).]
[Each applicant seeking approval for installation of an engine power control system that automatically resets thepower or thrust on the operating engine(s) when any engine fails during the takeo. must comply with the requirements of Appendix I of this part.] Amdt. 25-62, E.. 12/9/87
FAR 25.905 : Propellers.
(a)
Each propeller must have a type certi.cate.
(b)
Engine power and propeller shaft rotational speed may not exceed the limits for which the propeller is certi.cated.
′
Elodie Roux. Septembre 2003
Subpart E : Powerplant
(c)
Each component of the propeller blade pitch control system must meet the require-ments of Sec. 35.42 of this chapter
(d)
[Design precautions must be taken to minimize the hazards to the airplane in the event apropellerbladefails oris releasedby ahubfailure.The hazards which must be considered include damage to structure and vital systems due to impact of a failed or released blade and the unbalance created by such failure or release.]
Amdt. 25-72, E.. 8/20/90
FAR 25.907 : Propeller vibration.
(a)
The magnitude of thepropellerblade vibrationstressesunder any normal condition of operation must be determined by actual measurement or by comparison with similar installations for which these measurements have been made.
(b)
The determined vibration stresses may not exceed values that have been shown to be safe for continuous operation.
FAR 25.925 : Propeller clearance.
Unless smaller clearancesare substantiated,propeller clearanceswith the airplaneat maximum weight, with the most adverse center of gravity, and with the propeller in the most adversepitchposition, may notbelessthanthefollowing :
(a)
Ground clearance.There mustbe a clearance of atleast seveninches(for each air-plane withnose wheellandinggear) or nineinches(for each airplane with tail wheel landing gear) between each propeller and the ground with landing gear statically de.ected and in the level takeo., or taxiing attitude, whichever is most critical. In addition, there must be positive clearance between the propeller and the ground wheninthelevel takeo. attitude with the critical[tire(s)] completely de.ated and the corresponding landing gear strut bottomed.
(b)
Water clearance. There must be a clearance of at least 18 inches between each propeller and the water, unless compliance with Sec. 25.239(a) can be shown with a lesser clearance.
(c)
Structural clearance. There must be–
(1)
At least one inch radial clearance between the blade tips and the airplane structure, plus any additional radial clearance necessary to prevent harmful vibration;
(2)
At least one-half inch longitudinal clearance between the propeller blades or cu.s and stationaryparts of the airplane; and
(3)
Positiveclearancebetween otherrotatingpartsof thepropellerorspinnerand
stationaryparts of the airplane. Amdt. 25-72, E.. 8/20/90
FAR 25.929 : Propeller deicing.
(a)
For airplanes intended for use where icing may be expected, there must be a means to prevent or remove hazardous ice accumulation on propellers or on accessories whereice accumulation wouldjeopardize engineperformance.
(b)
If combustible .uidisusedforpropellerdeicing,Secs.25.1181 through25.1185 and 25.1189 apply.
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 3(111)
