1、Designation: F3116/F3116M 15Standard Specification forDesign Loads and Conditions1This standard is issued under the fixed designation F3116/F3116M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A number
2、 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 addresses the airworthiness require-ments for the design loads and conditions of small airplanes.1.2 This specification is
3、 applicable to small airplanes asdefined in the F44 terminology standard. Use of the termairplane is used throughout this specification and will mean“small airplane.”1.3 The applicant for a design approval must seek individualguidance from their respective CAA body concerning the useof this standard
4、 as part of a certification plan. For informationon which CAA regulatory bodies have accepted this standard(in whole or in part) as a means of compliance to their SmallAirplane Airworthiness Rules (hereinafter referred to as “theRules”), refer to ASTM F44 webpage (www.ASTM.org/COMMITTEE/F44.htm) whi
5、ch includes CAA website links.1.4 UnitsCurrently there is a mix of SI and Imperial units.In many locations, SI units have been included otherwise unitsare as they appear in Amendment 62 of 14 CFR Part 23. In afuture revision values will be consistently stated in SI unitsfollowed by Imperial units in
6、 square brackets. The valuesstated in each system may not be exact equivalents; therefore,each system shall be used independently of the other. Combin-ing values from the two systems may result in non-conformance with the standard.1.5 This standard does not purport to address all of thesafety concer
7、ns, if any, associated with its use. 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 ASTM Standards:2F3060 Terminology for Aircraft2.2 U.S. Co
8、de of Federal Regulations:314 CFR Part 23 Airworthiness Standards: Normal, Utility,Aerobatic and Commuter Category Airplanes (Amend-ment 62)2.3 European Aviation Safety Agency Regulations:Certification Specifications for Normal, Utility, Aerobatic,and Commuter Category Aeroplanes (CS-23, Amendment3)
9、Certification Specifications for Very Light Aeroplanes (CS-VLA, Amendment 1)3. Terminology3.1 A listing of terms, abbreviations, acronyms, and sym-bols related to aircraft covered by ASTM Committees F37 andF44 airworthiness design standards can be found in Terminol-ogy F3060. Items listed below are
10、more specific to thisstandard.3.2 Definitions of Terms Specific to This Standard:3.2.1 chordwise, ndirected, moving, or placed along thechord of an airfoil section.3.2.2 downwash, nthe downward deflection of an air-stream by an aircraft wing.3.2.3 flight envelope, nany combination of airspeed andloa
11、d factor on and within the boundaries of a flight envelopethat represents the envelope of the flight loading conditionsspecified by the maneuvering and gust criteria.3.2.4 flight load factor, nrepresents the ratio of the aero-dynamic force component (acting normal to the assumedlongitudinal axis of
12、the airplane) to the weight of the airplane.A positive flight load factor is one in which the aerodynamicforce acts upward, with respect to the airplane.3.2.5 propeller slipstream, nthe airstream pushed back bya revolving aircraft propeller.3.2.6 spanwise, ndirected, moving, or placed along thespan
13、of an airfoil.3.2.7 winglet, na nearly vertical airfoil at an airplaneswingtip.3.3 Acronyms:1This specification is under the jurisdiction ofASTM Committee F44 on GeneralAviation Aircraft and is the direct responsibility of Subcommittee F44.30 onStructures.Current edition approved May 1, 2015. Publis
14、hed July 2015. DOI: 10.1520/F3116_F3116M-15.2For referenced 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 U
15、.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.3.1 MCPmaximum continuous power3.4 Sym
16、bols:CNA= maximum airplane normal force coefficientMC= design cruising speed (Mach number)VE= design dive speed at zero or negative load factorVSF= stalling speed with flaps fully extended4. Flight Loads4.1 Loads:4.1.1 Unless otherwise provided, prescribed loads are limitloads.4.1.2 Unless otherwise
17、 provided, the air, ground, and waterloads must be placed in equilibrium with inertia forces,considering each item of mass in the airplane. These loads mustbe distributed to conservatively approximate or closely repre-sent actual conditions. Methods used to determine load inten-sities and distributi
18、on on canard and tandem wing configura-tions must be validated by flight test measurement unless themethods used for determining those loading conditions areshown to be reliable or conservative on the configuration underconsideration.4.1.3 If deflections under load would significantly changethe dist
19、ribution of external or internal loads, this redistributionmust be taken into account.4.1.4 Appendix X1 through Appendix X4 provides, withinthe limitations specified within the appendix, a simplifiedmeans of compliance with several of the requirements set forthin 4.2 to 4.26 and 7.1 to 7.9 that can
20、be applied as one (but notthe only) means to comply.4.2 General:4.2.1 Flight load factors, n, represent the ratio of theaerodynamic force component (acting normal to the assumedlongitudinal axis of the airplane) to the weight of the airplane.A positive flight load factor is one in which the aerodyna
21、micforce acts upward, with respect to the airplane.4.2.2 Compliance with the flight load requirements of thissubpart must be shown:4.2.2.1 At each critical altitude within the range in whichthe airplane may be expected to operate;4.2.2.2 At each weight from the design minimum weight tothe design max
22、imum weight; and4.2.2.3 For each required altitude and weight, for anypracticable distribution of disposable load within the operatinglimitations specified in 14 CFR Part 23, Sections 23.1583through 23.1589.4.2.3 When significant, the effects of compressibility mustbe taken into account.4.3 Symmetri
23、cal Flight Conditions:4.3.1 The appropriate balancing horizontal tail load must beaccounted for in a rational or conservative manner whendetermining the wing loads and linear inertia loads correspond-ing to any of the symmetrical flight conditions specified in 4.4through 4.6.4.3.2 The incremental ho
24、rizontal tail loads due to maneu-vering and gusts must be reacted by the angular inertia of theairplane in a rational or conservative manner.4.3.3 Mutual influence of the aerodynamic surfaces must betaken into account when determining flight loads.4.4 Flight Envelope:4.4.1 GeneralCompliance with the
25、 strength requirementsof this subpart must be shown at any combination of airspeedand load factor on and within the boundaries of a flightenvelope (similar to the one in 4.4.4) that represents theenvelope of the flight loading conditions specified by themaneuvering and gust criteria of 4.4.2 and 4.4
26、.3 respectively.4.4.2 Maneuvering EnvelopeExcept where limited bymaximum (static) lift coefficients, the airplane is assumed to besubjected to symmetrical maneuvers resulting in the followinglimit load factors:4.4.2.1 The positive maneuvering load factor specified in4.5 at speeds up to VD;4.4.2.2 Th
27、e negative maneuvering load factor specified in4.5 at VC; and4.4.2.3 Factors varying linearly with speed from the speci-fied value at VCto 0.0 at VD. For airplanes with a positive limitmaneuvering load factor greater than 3.8, use a value of 1.0 atVD.4.4.3 Gust Envelope:4.4.3.1 The airplane is assum
28、ed to be subjected to sym-metrical vertical gusts in level flight. The resulting limit loadfactors must correspond to the conditions determined asfollows:(1) Positive (up) and negative (down) gusts of 15.24 m/s50 fps at VCmust be considered at altitudes between sea leveland 6,096 m 20 000 ft. The gu
29、st velocity may be reducedlinearly from 15.24 m/s 50 fps at 6096 m 20 000 ft to 7.62m/s 25 fps at 15 240 m 50 000 ft; and(2) Positive and negative gusts of 7.62 m/s 25 fps at VDmust be considered at altitudes between sea level and 6,096 m20 000 ft. The gust velocity may be reduced linearly from7.62
30、m/s 25 fps at 6096 m 20 000 ft to 3.81 m/s 12.5 fpsat 15 240 m 50 000 ft.(3) In addition, for level 4 airplanes, positive (up) andnegative (down) rough air gusts of 20.12 m/s 66 fps at VBmust be considered at altitudes between sea level and 6096 m20 000 ft. The gust velocity may be reduced linearly
31、from20.12 m/s 66 fps at 6096 m 20 000 ft to 11.58 m/s 38 fpsat 15 240 m 50 000 ft.4.4.3.2 The following assumptions must be made:(1) The shape of the gust is:U 5Ude2S1 2 cos2s25CD(1)where:s = distance penetrated into gust (m or ft);C = mean geometric chord of wing (m or ft); andUde= derived gust vel
32、ocity referred to in 4.4.3.1 (m/s orfps).(2) Gust load factors vary linearly with speed between VCand VD.4.4.4 Flight EnvelopeSee Fig. 1.4.5 Limit Maneuvering Load Factors:4.5.1 The positive limit maneuvering load factor n may notbe less than:F3116/F3116M 1524.5.1.1 2.1 124,000W110,000, where W = de
33、sign maximum take-off weight (lb), except that n need not be more than 3.8;4.5.1.2 6.0 for airplanes approved for aerobatics.4.5.2 The negative limit maneuvering load factor may notbe less than:4.5.2.1 0.4 times the positive load factor;4.5.2.2 0.5 times the positive load factor for airplanesapprove
34、d for aerobatics.4.5.3 Maneuvering load factors lower than those specifiedin this section may be used if the airplane has design featuresthat make it impossible to exceed these values in flight.4.6 Gust Load Factors:4.6.1 Each airplane must be designed to withstand loads oneach lifting surface resul
35、ting from gusts specified in 4.4.3.4.6.2 The gust load factors for a canard or tandem wingconfiguration must be computed using a rational analysis, ormay be computed in accordance with 4.6.3, provided that theresulting net loads are shown to be conservative with respect tothe gust criteria of 4.4.3.
36、4.6.3 In the absence of a more rational analysis, the gustload factors must be computed as follows:n 5 11KgUdeVa498SWSD(2)where:Kg50.88g5.31g= gust alleviation factor;g52W S!Cag= airplane mass ratio;Ude= derived gust velocities referred to in 4.4.3(f.p.s.). = density of air (slugs/ft3);W/S = wing lo
37、ading (p.s.f.) due to the applicableweight of the airplane in the particular loadcase;C = mean geometric chord (ft);g = acceleration due to gravity (ft/s2);V = airplane equivalent speed (knots); anda = slope of the airplane normal force coefficientcurve CNAper radian if the gust loads areapplied to
38、the wings and horizontal tail sur-faces simultaneously by a rational method.The wing lift curve slope CLper radian maybe used when the gust load is applied to thewings only and the horizontal tail gust loadsare treated as a separate condition.4.7 Design Fuel Loads:4.7.1 The disposable load combinati
39、ons must include eachfuel load in the range from zero fuel to the selected maximumfuel load.4.7.2 If fuel is carried in the wings, the maximum allowableweight of the airplane without any fuel in the wing tank(s) mustbe established as “maximum zero wing fuel weight,” if it is lessthan the maximum wei
40、ght.4.7.3 For level 4 airplanes, a structural reserve fuelcondition, not exceeding fuel necessary for 45 min of operationat maximum continuous power, may be selected. If a structuralreserve fuel condition is selected, it must be used as theminimum fuel weight condition for showing compliance withthe
41、 flight load requirements prescribed in this part and:4.7.3.1 The structure must be designed to withstand acondition of zero fuel in the wing at limit loads correspondingto:NOTE 1Point G need not be investigated when the supplementary condition specified in 4.14 is investigated.FIG. 1 Flight Envelop
42、eF3116/F3116M 153(1) 90 % of the maneuvering load factors defined in 4.5,and(2) Gust velocities equal to 85 % of the values prescribedin 4.4.3.4.7.3.2 The fatigue evaluation of the structure must accountfor any increase in operating stresses resulting from the designcondition of 4.7.3.1.4.7.3.3 The
43、flutter, deformation, and vibration requirementsmust also be met with zero fuel in the wings.4.8 High Lift Devices:4.8.1 If wing flaps or similar high lift devices are installedfor use in take-off, approach, or landing, the airplane, with theflaps fully deflected at VF, is assumed to be subjected to
44、symmetrical maneuvers and gusts resulting in limit load factorswithin the range determined by:4.8.1.1 Maneuvering, to a positive limit load factor of 2.0;and4.8.1.2 Positive and negative gust of 7.62 m/s 25 fpsacting normal to the flight path in level flight.4.8.1.3 However, if an automatic flap loa
45、d limiting device isused, the airplane may be designed for the critical combina-tions of airspeed and flap position allowed by that device.4.8.2 VFmust be assumed to be not less than 1.4 VSor 1.8VSF, whichever is greater, where:4.8.2.1 VSis the 1g computed stalling speed with flapsretracted at the d
46、esign weight; and4.8.2.2 VSFis the 1g computed stalling speed with flapsfully extended at the design weight.4.8.3 In determining external loads on the airplane as awhole, thrust, slipstream, and pitching acceleration may beassumed to be zero.4.8.4 The flaps, their operating mechanism, and their sup-
47、porting structures, must be designed for the conditions pre-scribed in 4.8.1. In addition, with the flaps fully extended at VF,the following conditions, taken separately, must be accountedfor:4.8.4.1 A head-on gust having a velocity of 7.62 m/s 25fps (EAS), combined with propeller slipstream corresp
48、ondingto 75 % of maximum continuous power; and4.8.4.2 The effects of propeller slipstream corresponding tomaximum takeoff power.4.8.4.3 For the investigation of slipstream effects, the loadfactor may be assumed to be 1.0.4.9 Unsymmetrical Flight Conditions:4.9.1 The airplane is assumed to be subject
49、ed to the unsym-metrical flight conditions of 4.10 and 4.11. Unbalanced aero-dynamic moments about the center of gravity must be reactedin a rational or conservative manner, considering the principalmasses furnishing the reacting inertia forces.4.9.2 Airplanes approved for aerobatics must be designedfor additional asymmetric loads acting on the wing and thehorizontal tail.4.10 Rolling ConditionsThe wing and wing bracing mustbe designed for the following loading conditions:4.10.1 Unsymmetrical wing loads. Unless
