1、Designation: F3231/F3231M 17Standard Specification forElectrical Systems in Small Aircraft1This standard is issued under the fixed designation F3231/F3231M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers international standards for theelectrical systems aspects of airworthiness and design for“small” aircraft.
3、1.2 The applicant for a design approval must seek theindividual guidance of their respective CAA body concerningthe use of this specification as part of a certification plan. Forinformation on which CAA regulatory bodies have acceptedthis specification (in whole or in part) as a means of compli-ance
4、 to their Small Aircraft Airworthiness regulations (herein-after referred to as “the Rules”), refer to ASTM F44 webpage(www.ASTM.org/COMMITTEE/F44.htm) which includesCAA website links.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values st
5、ated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its us
6、e. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 Following is a list of external standards referencedthroughout this specification; the earl
7、iest revision acceptablefor use is indicated. In all cases later document revisions areacceptable if shown to be equivalent to the listed revision, or ifotherwise formally accepted by the governing civil aviationauthority; earlier revisions are not acceptable.2.2 ASTM Standards:2F3060 Terminology fo
8、r AircraftF3061/F3061M Specification for Systems and Equipment inSmall AircraftF3066/F3066M Specification for Powerplant Systems Spe-cific Hazard MitigationF3117/F3117M Specification for Crew Interface in AircraftF3235 Specification for Electrical Storage Batteries in SmallAircraft2.3 FAA Standard:D
9、OT/FAA/AR-00/12 Aircraft Materials Fire Test Hand-book33. Terminology3.1 Terminology specific to this specification is providedbelow. For general terminology, refer to Terminology F3060.3.2 Definitions of Terms Specific to This Standard:3.2.1 aircraft type code, nan Aircraft Type Code (ATC) isdefine
10、d by considering both the technical considerations re-garding the design of the aircraft and the airworthiness levelestablished based upon risk-based criteria; the method ofdefining an ATC applicable to this specification is defined inSpecification F3061/F3061M.3.2.2 continued safe flight and landin
11、g, ncontinued safeflight and landing as applicable to this specification is definedin Specification F3061/F3061M.4. Electrical SystemsNOTE 1Table 1 provides correlation between various Aircraft TypeCodes and the individual requirements contained within this section; referto 3.2.1. For each subsectio
12、n, an indicator can be found under each ATCcharacter field; three indicators are used:An empty cell ( ) in all applicable ATC character field columnsindicates that an aircraft must meet the requirements of that subsection.A white circle () in multiple columns indicates that the requirementsof that s
13、ubsection are not applicable to an aircraft only if all such ATCcharacter fields are applicable.A mark-out () in any of the applicable ATC character field columnsindicates that the requirements of that subsection are not applicable to anaircraft if that ATC character field is applicable.ExampleAn ai
14、rcraft with anATC of 1SRLLDLN is being considered.Since all applicable columns are empty for 4.2.1, that subsection isapplicable to the aircraft. Since both the “L” stall speed column and the“D” meteorological column for 4.1.1 contain white circles, then thatsubsection is not applicable; however, fo
15、r an aircraft with an ATC of1This specification is under the jurisdiction ofASTM Committee F44 on GeneralAviation Aircraft and is the direct responsibility of Subcommittee F44.50 onSystems and Equipment.Current edition approved Feb. 15, 2017. Published March 2017. DOI: 10.1520/F3231_F3231M-17.2For r
16、eferenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Federal Aviation Administration (FAA), 800 Independ
17、enceAve., SW, Washington, DC 20591, http:/www.faa.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in
18、the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1TABLE 1 ATC Compliance Matrix, Section 4SectionAirworthiness Level Number ofEnginesType ofEngine(s)Stall Speed Crui
19、se Speed MeteorologicalConditionsAltitude Maneuvers1234SMRTLMHLHDNILHNA44.14.1.1 CC4.1.1.14.1.1.24.1.1.34.1.1.44.1.1.5 CC4.1.1.64.24.2.14.2.1.1 4.2.1.2 4.2.24.2.34.2.44.2.54.2.64.2.7 4.2.8 4.2.9 4.2.10 4.2.11 4.2.124.2.12.14.2.12.24.2.12.34.2.12.44.2.12.54.2.12.64.2.12.74.2.134.2.13.14.2.13.2 4.2.14
20、4.2.154.2.164.2.17 CC4.2.17.14.2.17.24.34.3.14.3.1.14.3.1.24.3.1.34.3.24.3.34.3.44.3.54.3.6 CC4.3.7 4.44.4.14.4.1.14.4.1.24.4.24.4.34.4.44.4.54.4.5.14.54.5.14.5.24.5.34.5.44.5.4.14.5.4.24.64.6.14.6.24.74.7.1F3231/F3231M 1721SRMLDLN, 4.1.1 would be applicable since the “M” stall speed columndoes not
21、contain a white circle. 4.2.1.2 would not be applicable to eitheraircraft, since it contains an in the “1” airworthiness level column.NOTE 2This section provides specifications for the electrical genera-tion and distribution systems used to power various aircraft systems andequipment. It intentional
22、ly does not address any electrical power systemsthat may be employed in electrically-powered aircraft propulsion systems;such power systems are outside the scope of this section.4.1 Power Source Capacity and Distribution:4.1.1 Each installation whose functioning is required fortype certification or
23、under operating rules and that requires apower supply is an “essential load” on the power supply. Thepower sources and the system must be able to supply the powerloads specified in 4.1.1.1 4.1.1.6 in probable operatingcombinations and for probable durations. The power loads maybe assumed to be reduc
24、ed under a monitoring procedureconsistent with safety in the kinds of operation authorized.Loads not required in controlled flight need not be consideredfor the two-engine-inoperative condition on aircraft with threeor more engines.4.1.1.1 When required by 4.1.1, the power sources and theelectrical
25、distribution system, when functioning normally mustbe able to support all connected loads.4.1.1.2 When required by 4.1.1, the power sources and theelectrical distribution system must be able to support allessential loads after the failure of any one engine.4.1.1.3 When required by 4.1.1, the power s
26、ources and theelectrical distribution system must be able to support allessential loads after the failure of any one power converter.4.1.1.4 When required by 4.1.1, the power sources and theelectrical distribution system must be able to support allessential loads after the failure of any one energy
27、storagedevice.4.1.1.5 When required by 4.1.1, the power sources and theelectrical distribution system must be able to support allessential loads after the failure of any two engines on aircraftwith three or more engines.4.1.1.6 When required by 4.1.1, the power sources and theelectrical distribution
28、 system must be able to support allessential loads for which an alternate source of power isrequired, after any failure or malfunction in any one powersupply system, any one distribution system, or any otherutilization system.4.2 Electrical Systems and Equipment:4.2.1 Electric power sources, their t
29、ransmission cables, andtheir associated control and protective devices must be able tofurnish the required power at the proper voltage to each loadcircuit essential for safe operation.4.2.1.1 Compliance with 4.2.1 must be shown by an elec-trical load analysis or by electrical measurements that accou
30、ntfor the electrical loads applied to the electrical system inprobable combinations and for probable durations.4.2.1.2 Compliance with 4.2.1 must be shown by an elec-trical load analysis that accounts for the electrical loads appliedto the electrical system in probable combinations and forprobable d
31、urations.4.2.2 Each electrical system, when installed, must be freefrom hazards in itself, in its method of operation, and in itseffects on other parts of the aircraft.4.2.3 Each electrical system, when installed, must be pro-tected from fuel, oil, water, other detrimental substances, andmechanical
32、damage.4.2.4 Each electrical system, when installed, must be de-signed so that the risk of electrical shock to crew, passengers,and ground personnel is reduced to a minimum.4.2.5 Electric power sources must function properly whenconnected in combination or independently.4.2.6 No failure or malfuncti
33、on of any electric power sourcemay impair the ability of any remaining source to supply loadcircuits essential for safe operation.4.2.7 Each system must be designed so that essential loadcircuits can be supplied in the event of reasonably probablefaults or open circuits including faults in heavy cur
34、rentcarrying cables.4.2.8 A means must be accessible in flight to the flightcrewmembers for the individual and collective disconnectionof the electrical power sources from the system.4.2.9 The system must be designed so that voltage andfrequency, if applicable, at the terminals of all essential load
35、equipment can be maintained within the limits for which theequipment is designed during any probable operating condi-tions.4.2.10 If any particular system or item of equipment re-quires two independent sources of electrical power, theirTABLE 1 ContinuedSectionAirworthiness Level Number ofEnginesType
36、 ofEngine(s)Stall Speed Cruise Speed MeteorologicalConditionsAltitude Maneuvers1234SMRTLMHLHDNILHNA4.7.24.7.34.7.44.7.5 4.7.64.7.7 4.7.8 4.84.8.1 4.8.2 4.8.3 4.94.9.14.9.2F3231/F3231M 173electrical energy supply must be ensured by means such asduplicate electrical equipment, throwover switching, or
37、by theuse of multichannel or loop circuits separately routed.4.2.11 For the purpose of complying with 4.2.6 4.2.10, thedistribution system includes the distribution busses, theirassociated feeders, and each control and protective device.4.2.12 There must be at least one generator/alternator if theel
38、ectrical system supplies power to load circuits essential forsafe operation. In addition, the requirements of 4.2.12.1 4.2.12.7 must be met.4.2.12.1 Each generator/alternator must be able to deliver itscontinuous rated power, or such power as is limited by itsregulation system.4.2.12.2 Generator/alt
39、ernator voltage control equipmentmust be able to dependably regulate the generator/alternatoroutput within rated limits.4.2.12.3 Automatic means must be provided to preventdamage to any generator/alternator due to reverse current intothe generator/alternator.4.2.12.4 Automatic means must be provided
40、 to preventadverse effects on the aircraft electrical system due to reversecurrent into the generator/alternator.4.2.12.5 A means must be provided to disconnect eachgenerator/alternator from the battery and other generators/alternators.4.2.12.6 There must be a means to give immediate warningto the f
41、light crew of a failure of any generator/alternator.4.2.12.7 Each generator/alternator must have an overvoltagecontrol designed and installed to prevent damage to theelectrical system, or to equipment supplied by the electricalsystem that could result if that generator/alternator were todevelop and
42、overvoltage condition.4.2.13 A means must exist to indicate to appropriate flightcrewmembers the electric power system quantities essential forsafe operation.4.2.13.1 For aircraft with direct current systems, an amme-ter that can be switched into each generator/alternator feedermay be used and, if o
43、nly one generator/alternator exists, theammeter may be in the battery feeder.4.2.13.2 The essential electric power system quantities in-clude the voltage and current supplied by each generator/alternator.4.2.14 Electrical equipment must be so designed and in-stalled that in the event of a fire in th
44、e engine compartment,during which the surface of the firewall adjacent to the fire isheated to 1095C 2000F for 5 min or to a lesser temperaturesubstantiated by the applicant, the equipment essential tocontinued safe operation and located behind the firewall willfunction satisfactorily and will not c
45、reate an additional firehazard.4.2.15 If provisions are made for connecting external powerto the aircraft, and that external power can be electricallyconnected to equipment other than that used for enginestarting, means must be provided to ensure that no externalpower supply having a reverse polarit
46、y, or a reverse phasesequence, can supply power to the aircraft electrical system.4.2.16 If provisions are made for connecting external powerto the aircraft, and that external power can be electricallyconnected to equipment other than that used for enginestarting, the external power connection must
47、be located so thatits use will not result in a hazard to the aircraft or groundpersonnel.4.2.17 It must be shown by analysis, tests, or both, that theaircraft can be operated safely in VFR conditions, for a periodof not less than 5 min, with the normal electrical power(electrical power sources exclu
48、ding the battery and any otherstandby electrical sources) inoperative, with critical type fuel(from the standpoint of flameout and restart capability), andwith the aircraft initially at the maximum certificated altitude.4.2.17.1 In showing compliance with 4.2.17, parts of theelectrical system may re
49、main on if a single malfunction,including a wire bundle or junction box fire, cannot result inloss of the part turned off and the part turned on.4.2.17.2 In showing compliance with 4.2.17, parts of theelectrical system may remain on if the parts turned on areelectrically and mechanically isolated from the parts turned off.4.3 Storage Battery Design and Installation:4.3.1 Each storage battery design and installation mustmaintain safe cell temperatures and pressures during anyprobable charging and discharging condition.4.3.1.1 No uncont
