(b)
If a single fuel tank is used on a multiengine rotorcraft, the following must be pro-vided :
(1)
Independent tank outletsfor each engine, eachincorporating a shuto. valve at thetank.Thisshuto.valvemay alsoserveasthe .rewall shuto.valverequired by Sec. 27.995 if the line between the valve and the engine compartment does not contain a hazardous amount of fuel that can drain into the engine compartment.
(2)
Atleast two vents arrangedto minimize theprobabilityofboth ventsbecoming obstructed simultaneously.
(3)
Filler caps designed to minimize the probability of incorrect installation or in.ight loss.
(4)
Afuel systemin which thoseparts of the systemfrom each tank outletto any engine are independent of each part of each system supplying fuel to other engines.
FAR27.954 :[Fuel systemlightningprotection.]
[Thefuelsystem mustbedesigned and arranged topreventtheignition offuel vapor within the system by–
(a)
Direct lightning strikes to areas having a high probability of stroke attachment;
(b)
Swept lightning strokes to areas where swept strokes are highly probable; or
(c)
Corona and streamering at fuel vent outlets.] Amdt. 27-23, E.. 10/3/88
FAR 27.955 : Fuel .ow
(a)
[General.Thefuel systemforeach engine mustbe showntoprovidethe engine with at least 100 percent of the fuel required under each operating and maneuvering conditiontobe approvedforthe rotorcraftincluding, as applicable,thefuel required to operate the engine(s) under the test conditions required by Sec. 27.927. Unless equivalent methods are used, compliance must be shown by test during which the followingprovisions are metexceptthat combinations of conditions which are shown to be improbable need not be considered.
(1)
Thefuelpressure, correctedfor criticalaccelerations, mustbe within thelimits speci.ed by the engine type certi.cate data sheet.
(2)
Thefuellevelin the tankmay not exceed that established as unusablefuel sup-plyfor the tankunderSec.27.959,plus the minimum additionalfuel necessary to conduct the test.
(3)
The fuel head between the tank outlet and the engine inlet must be critical with respect to rotorcraft .ight attitudes.
(4)
The criticalfuelpump(forpump-fedsystems)isinstalledtoproduce(by actual or simulated failure) the critical restriction to fuel .ow to be expected from pump failure.
(5)
Critical values of engine rotation speed, electrical power, or other sources of fuel pump motive power must be applied.
(6)
Critical values of fuel properties which adversely a.ect fuel .ow must be ap-plied.
(7)
Thefuel .lterrequiredbySec.27.997 mustbeblocked tothedegreenecessary to simulate the accumulation of fuel contamination required to activate the indicator required by Sec. 27.1305(q).
(b)
Fuel transfer systems. If normal operation of the fuel system requires fuel to be transferred to an engine feed tank, the transfer must occur automatically via a system which has been shown to maintain the fuel level in the engine feed tank within acceptable limits during .ight or surface operation of the rotorcraft.
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Elodie Roux. Septembre 2003
Subpart E : Powerplant
(c) Multiple fuel tanks. If an engine can be supplied with fuel from more than one tank, thefuel system must,in additiontohaving appropriate manual switching capability, be designed to prevent interruption of fuel .ow to that engine, without attention by the .ightcrew,whenany tank supplyingfuel tothatengineisdepleted of usable fuel during normal operation, and any other tank that normally supplies fuel to the engine alone contains usable fuel.]
Amdt. 27-23, E.. 10/3/88
FAR 27.959 : Unusable fuel supply
The unusable fuel supply for each tank must be established as not less than the quantity at which the .rst evidence of malfunction occurs under the most adverse fuel feed condition occurring under any intended operations and .ight maneuvers involving that tank.
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 4(108)
