(c)
Cooling tests for each stage of .ight must be continued until–

(1)
The component and engine .uid temperatures stabilize;

(2)
Thestageof .ightiscompleted; or

(3)
An operating limitation is reached.

(d)
For reciprocating engine powered airplanes, it may be assumed, for cooling test purposes, that the takeo. stage of .ight is complete when the airplane reaches an altitude of 1,500 feet above the takeo. surface or reaches a point in the takeo. where the transitionfrom the takeo. to the en route con.gurationis completed and a speedis reached at which compliance with[Sec.25.121(c)] is shown, whichever pointis at ahigher altitude.[The airplane mustbeinthefollowing con.guration:

(1)
Landing gear retracted.

(2)
Wing .apsinthemostfavorableposition.

(3)
Cowl .aps (or other means of controlling the engine cooling supply) in the position that provides adequate cooling in the hot-day condition.

(4)
Critical engine inoperative and its propeller stopped.

(5)
Remaining engines at the maximum continuous power available for the alti-tude.]

(e)
Forhull seaplanesand amphibians,cooling mustbe shownduring taxiingdownwind for 10 minutes, at 5 knots above step speed.

Amdt. 25-57, E.. 3/26/84
48.6 Induction System
FAR 25.1091 : Air induction.
(a)
The airinduction systemfor each engine and auxiliarypower unit must supply–

(1)
The air requiredby that engine and auxiliarypower unit under each operating condition for which certi.cation is requested; and

(2)
The air for proper fuel metering and mixture distribution with the induction system valves in any position.

(b)
Each reciprocating engine musthavean alternateairsourcethatpreventsthe entry of rain, ice, or any other foreign matter.

(c)
Air intakes may not open within the cowling, unless-

(1)
Thatpart of the cowlingisisolatedfrom the engine accessory sectionby means of a .reproof diaphragm; or

(2)
For reciprocatingengines, there are means toprevent the emergence ofback.re .ames.

(d)
For turbine engine powered airplanes and airplanes incorporating auxiliary power units–

(1)
There mustbe meanstopreventhazardousquantities offuelleakage or over-.ow from drains, vents, or other components of .ammable .uid systems from entering the engine or auxiliarypower unitintake system; and

(2)
The airplane must be designed to prevent water or slush on the runway, taxi-way, or other airport operating surfacesfrombeing directedinto the engine or auxiliary power unit air inlet ducts in hazardous quantities, and the air inlet ducts must be located or protected so as to minimize the ingestion of foreign matter during takeo., landing, and taxiing.

(e)
[Ifthe engineinduction system containsparts or components that couldbedamaged byforeign objects enteringthe airinlet,itmustbe shownby tests or,if appropriate, by analysis that the induction system design can withstand the foreign object ingestiontestconditions ofSecs.33.76,33.77 and33.78(a)(1) ofthis chapter without failure of parts or components that could create a hazard.]

Amdt. 25-100, E.. 12/13/2000
FAR 25.1093 : Induction system icing protection.
(a)
Reciprocating engines. Each reciprocating engine air induction system must have means to prevent and eliminate icing. Unless this is done by other means, it must be shown that, in air free of visible moisture at a temperature of 30'F., each airplane with altitude engines using–

(1)
Conventional venturi carburetorshave apreheater that canprovide a heat rise of 120'F. withthe engine at60percent of maximum continuouspower; or

(2)
Carburetors tending to reduce the probability of ice formation has a prehea-ter that can provide a heat rise of 100'F. with the engine at 60 percent of maximum continuouspower.
　
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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 4(4)