(i)
One1-inch(25 millimeters)diameterhailstonefor engines withinlet areas of not morethan100 squareinches(0.0645 square meters).

(ii)
One 1-inch (25 millimeters) diameter and one 2-inch (50 millimeters) diameterhailstonefor each150 squareinches(0.0968 squaremeters) of inlet area, or fraction thereof, for engines with inlet areas of more than 100 squareinches(0.0645 square meters).

(2)
In addition to complying withparagraph(a)(1) of this section and except as providedinparagraph(b) ofthis section,it mustbe shownthat each engine is capableof acceptable operationthroughoutits speci.ed operating envelope when subjected to sudden encounters with the certi.cation standard concen-trations of rain and hail, as de.ned in Appendix B to this part. Acceptable engineoperationprecludes .ameout,rundown,continued ornon-recoverable surge or stall, or loss of acceleration and deceleration capability, during any three minute continuous period in rain and during any 30 second continuous period in hail. It must also be shown after the ingestion that there is no unacceptable mechanicaldamage, unacceptablepower orthrustloss, or other adverse engine anomalies.

(b)
Engines for rotorcraft. As an alternative to the requirements speci.ed in paragraph (a)(2) of this section, for rotorcraft turbine engines only, it must be shown that each engineis capable of acceptable operationduring and after theingestion of rain with an overall ratio of water droplet .ow to air.ow, by weight, with a uniform distribution at theinletplane, of atleastfourpercent.Acceptable engine operation precludes .ameout,rundown,continuedornon-recoverablesurgeorstall,orlossof acceleration and deceleration capability. It must also be shown after the ingestion that thereis no unacceptable mechanicaldamage, unacceptablepowerloss, or other adverseengine anomalies.The rainingestionmust occurunderthefollowing static ground level conditions :

(1) Anormal stabilizationperiod attake-o.power without rainingestion,followed immediately by the suddenly commencing ingestion of rain for three minutes at takeo. power, then
′
Elodie Roux. Septembre 2003
SubpartE :Design andConstruction;TurbineAircraftEngines
(2)
Continuation of the rain ingestion during subsequent rapid deceleration to minimum idle, then

(3)
Continuation ofthe rainingestionduringthree minutes at minimumidlepower to be certi.ed for .ight operation, then

(4)
Continuation of the rain ingestion during subsequent rapid acceleration to takeo. power.

(c)
Enginesforsupersonicairplanes.Inadditionto complying withparagraphs(a)(1) and(a)(2) of thissection, aseparatetestforsupersonicairplaneenginesonly, shall be conducted with three hailstones ingested at supersonic cruise velocity. These hailstones shall be aimed at the engine’s critical face area, and their ingestion must not cause unacceptable mechanical damage or unacceptable power or thrust loss after the ingestion or require the engine to be shut down. The size of these hailstones shallbedeterminedfrom thelinear variationindiameterfrom1-inch(25 millimeters) at35,000feet(10,500 meters) to1/4-inch(6 millimeters) at60,000feet (18,000meters) using thediameter correspondingto thelowest expected supersonic cruise altitude. Alternatively, three larger hailstones may be ingested at subsonic velocitiessuch thatthekinetic energy of theselargerhailstonesis equivalenttothe applicable supersonic ingestion conditions.

(d)
For an engine that incorporates or requires the use of a protection device, demons-tration of the rain and hail ingestion capabilities of the engine, as required in paragraphs(a),(b), and(c) of thissection,maybewaived wholly orinpartby the Administrator if the applicant shows that :

(1)
The subject rain and hail constituents are of a size that will not pass through the protection device;

(2)
The protection device will withstand the impact of the subject rain and hail constituents; and
　
中國航空網(wǎng) www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：FAA規(guī)章 美國聯(lián)邦航空規(guī)章 Federal Aviation Regulations 5(141)