FAR 25.933 : Reversing systems.
(a)
[For turbojet reversingsystems–

(1)
Each system intended for ground operation only must be designed so that during any reversal in .ight the engine will produce no more than .ight idle thrust. In addition, it must be shown by analysis or test, or both, that–

(i)
Eachoperable reverser canbe restored to theforwardthrustposition; and

(ii)
The airplane is capable of contained safe .ight and landing under any possible position of the thrust reverser.

(2)
Eachsystemintendedforin.ight use mustbedesigned so that no unsafe condi-tion will resultduring normal operationof the system, orfrom any failure(or reasonably likely combination of failures) of the reversing system, under any anticipated conditionof operationof the airplaneincludingground operation. Failure of structural elements need notbe consideredif theprobability of this kind of failure is extremely remote.

(3)
Each system must have means to prevent the engine from producing more than idle thrust when the reversing system malfunctions, except that it may produce any greater forward thrust that is shown to allow directional control to be maintained, with aerodynamic means alone, under the most critical reversing condition expected in operation.

(b)
For propeller reversing systems–

(1)
Each system intended for ground operation only must be designed so that no singlefailure(or reasonablylikely combination offailures) or malfunction of the system will resultin unwanted reversethrust under any expected operating condition.Failureof structural elementsneed notbe consideredif thiskind of failure is extremely remote.

(2)
Compliance with this section may be shown by failure analysis or testing, or both,forpropellersystemsthatallowpropellerbladestomovefromthe .ight low-pitch position to a position that is substantially less than that at the normal .ightlow-pitchposition.Theanalysismayincludeorbesupportedby the analysis made to show compliance with the requirements of Sec. 35.21 of this chapter for the propeller and associated installation components.]

Amdt. 25-72, E.. 8/20/90
FAR25.934:[Turbojetenginethrustreverser systemtests.]
[Thrust reversers installed on turbojet engines must meet the requirements of Sec.
33.97 of this chapter.] Amdt. 25-23, E.. 5/8/70
FAR 25.937 : Turbopropeller-drag limiting systems.
Turbopropellerpowered airplanepropeller-draglimiting systemsmustbedesigned so that no single failure or malfunction of any of the systems during normal or emergency operation results in propeller drag in excess of that for which the airplane was designed under Sec. 25.367. Failure of structural elements of the drag limiting systems need not be considered if the probability of this kind of failure is extremely remote.
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Elodie Roux. Septembre 2003
Subpart E : Powerplant
FAR 25.939 : Turbine engine operating characteristics.
(a)
Turbine engine operating characteristics must be investigated in .ight to determine thatnoadversecharacteristics(suchasstall,surge,or .ameout) arepresent,to a hazardous degree, during normal and emergency operation within the range of operation limitations of the airplane and of the engine.

(b)
[[Reserved.]]

(c)
The turbine engine air inlet system may not, as a result of air .ow distortion during normal operation, cause vibration harmful to the engine.

Amdt. 25-40, E.. 5/2/77
FAR25.941:[Inlet,engine,and exhaustcompatibility.]
[For airplanes usingvariable inlet or exhaust system geometry, or both–
(a)
The system comprisedof theinlet, engine(including thrust augmentation systems,if incorporated), and exhaust mustbe shown tofunctionproperly under all operating conditions for which approval is sought, including all engine rotating speeds and power settings, and engine inlet and exhaust con.gurations;
　
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本文鏈接地址：FAA規(guī)章 美國聯(lián)邦航空規(guī)章 Federal Aviation Regulations 3(112)