1、MIL-A-6865B(AS)20 Nay 1987-.-SUPERSEDINGMJL-A-8865(ASG)18 May 1960MILITARY SPECIFICATIONAIRPLANE STRENGTH ANO RIGIDITY MISCELLANEOUS LOAOSThis specification is approved for usd within the Naval Alr SystemsCommand, Department of the Navy, and Is available for use by ailDepartments and Agencies of the
2、 Department of Defense.1. SCOPE1.1 we. This speclfcation contains the strength and rigidityrequirements for miscellaneous load: applicable to acquiltlon of airplanes.2. APPLICABLE DOCUMENTS2.I Government documents.2.1.1 Specifications. The following specifications form a part of thisspecification to
3、 the extent specified herein. Unless otherwise specified,the issues of these documents shall be those iisted in the issue of theDepartment of Defense Index of Specifications and Standards (0001SS) andsupplement thereto, cited in the solicitation.SPECIFICATIONSMILITARYMIL-D-8708 Demonstration Require
4、ments for Airplanes.MIL-A-8867 Airplane Strength and Rigidity - Ground TestsMIL-A-8868 Airpiane Strength and Rigidity - Data andReports.(Copies of specifications required by contractors in connection withspecific acquisition functions shouid be obtained from the contractingactivity or as directed by
5、 the contracting activity.)-. .Beneflclal comments (recommendations, additions, deletions) and any pertinentdata which may be of use in lmprovlng this document should be addressed to:Systems Engineering and Standardization Department (Code 93), Naval AirEngineering Center, Lakehurst, NJ 08733-5100,
6、by using the self-addressedStandardization Document Improvement Proposai (DD Form 1426) appearing at theend of this document or by letter. .-. -. -.AMSC NIADISTRIBUTION STATEMENT A Approved for public release; distribu. . .FSC i5i0ion is unlimited.Provided by IHSNot for ResaleNo reproduction or netw
7、orking permitted without license from IHS-,-,-MIL-A-8865B(AS)2.2 Order of precedence. In the event of a conflict between the text of.this specification and the references cited herein (ecept for associateddetail speclflcatlons, specification sheets or MS standards), the text of thisspecificaton shal
8、l take precedence. Nothing in this speciflcat!on, however,shall supersede applicable laws and regulations unless a speclflc exemptionhas been obtained.3. REQUIREMENTS3.1 . The loads specified in 3.2, 3.3, and 3.4 are ultlmate loads.For paragraphs other than 3.2, 3.3, and 3.4, the loads are limit loa
9、ds.3.2 Crash loads. The loads and loading conditions specified herein areultimate and are applicable to the design of crew seats, passenger seats,troop seats,litters, capsules, mechanisms for holding canopies and dcors intheir open posltlons, attachments of equipment items, cargo, engines, fueltanks
10、, turrets, and aerial delivery equipment, and their carry-throughstructures, These loads may be neglected for those 1ternsthe failure ofwhich could not result In Injury to personnel or prevent egress from thecrashed airplane. Fuel tanks shall contain that fuel which remains afterone-half of the tota
11、l internal fuel has been expended in a normal manner.The loads of 3.2.1 shall apply, except that litter loads shall be tnaccordance with 3.2.2.3.2.1 Crash load factors. The minimum longitudinal, vertical, and lateralload factors shal1 equai the uitimate load factors required for the strengthof crew
12、or passenger seats az spcclf!ed In the applicable specifications forsuch seats, or shall be in accordance with Table I if no seat specification isapplicable.TABLE 1. Longitudinal load factors for seat installations. AlAll carrier-based airplanes.All land-based airplanesexcept 40VR, VP, , VS. VU, VA,
13、 VE,VT or VC /I40I2Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8865B(AS)TABLE I. oltudinal load factors for seat installations. / - Continued. / The longitudinal load factor shall be directed in all forward azimuthswthn 20” from the ongitud
14、lnal axis. The vertical load factor shallbe directed downward, normal to the longitudinal axis, and equal toone-half of the longitudinal values. The sDec!fled load factors shallact separately. -Mission symbols:A - AttackC . CargoE = ElectronicP = PatrolR = ReconnaissanceS - AntlsutzmarlneT .STrainer
15、U=utlllty3.2.2 Litter installation loads. For litterload factors, acting separately, shall apply to atnstallatlons, the following250-pound 1itter load:Longitudinal 8.0 forwardLateral 1.5 to right and to leftVertical 4.5 down2.0 up3.3 Assisted takeoff. The loads specified in this paragraph shall beco
16、nsidered as airplane loading conditions rather than local loadingconditions. A forward acting load of 2.5 times the rated thrust at 60”F shalIact separately and In combination with all critical comblnat!ons of thefollowing inertial ioads acting at the attachments of each unit: A downwardload of 3.OW
17、, an upward load of 1.5W, and a lateral load of 1.5W to the rightand alternately to the left, in which )4Is the weight of the fully loaded unit.3.4 Ditching. When the ditching specified ultimate loads are applied tothe structure, there shall be no structural failure which, If occurring atsea, would
18、cause the airplane to submerge rapidly, cause injury to the crew,or In any other way prevent the crew from making a satisfactory escape fromthe ditched airplane. In general , lt is unnecessary to provide strength forpreventing failures which do not lead to complete rupture of the localstructure conc
19、erned. It is intended that strength be provided only to theextent necessary to prevent failures which reduce the crews chance ofeffecting a safe escape.3.4.I Water pressures. Bomb doors, hatch covers, windows, wheel wellcovers, and other structures covering cutout areas of the fuselage structure,fai
20、lure of which would cause undesirable uater behavior or allow rapid entryof water, shall not fall under the pressure specified in Table II, whenlocated in the areas over which these pressures are specified to act.Structures covering cutout areas lying in any one of the followingcombinations of areas
21、, designated in column I of Table II, shall be assumedto be lodded simultaneously: a and b, b and c, c and d, and d and e.Strength shall be provided in the carry-through structures supporting thedoors, windows, and covers to the extent, and in the amount required to assure3Provided by IHSNot for Res
22、aleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8865B(AS)compliance with the general requirements stated In 3.4. Table 11 definespressures and the areas over which these pressures are specffied to act.areas are bounded by the longitudinal stations in column 2, where the
23、setheThestations are specified in pecent of the overall length of the airplane aft ofthe most forward portion of the airplane structure. Columns 3 and 4 specifythe pressures to be applied, between the longitudinal stations Indicated incolumn 2, to the lower and upper halves of the fuselage, respecti
24、vely. Thesepressures are to be considered as normal pressues.TABLE II. Water pressures in ditching.AreaabcdeLongitudinal station(In percent)o-55-1o10 - 2525- 6060 - 80Pressure over lowerhalf of fuselage, psi1212864Pressure over upperhalf of fuselage, psl1260003.5 Floor strength. The limlt fllght loa
25、ds floor pressures shall be 75n. Pounds Per suare foot (psf) for personnel floors, 100 n, Dsf for 10W-densitv caiao areas. and 300 n, Dsf for all other carqo areas”where n, Isthe malmum-symme trical flight l“imitload factor. Thtraight lineioining the top of:he stick grip andthe pivot pointiach force
26、 in samejirection perpen-dicular to the pianeof the wheelPerpendicular to theplane of the wheel-. .- -. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I,11,I1)II,1II i tIrplane)ntrol-rect!onaBrakeMIL-A-8B65B(AS)TABLE III . Pilot applied loads. - Con
27、tinuedockpltontrol2ludderledalBrakepedaliumbelofForce12122=agnitudef each Point offorce appltcatlonunds)4 5300 Point ofcontact offoot WIthpedal1300 Each forceat Point ofcontact offoot witheach pedal11-Soo Point ofcontact offoot withpedal300 Each forceat point ocontact offoot ultheach pedalDirection6
28、aral lel to the pro-ection on the alr-llane plane of sym-Mtry of a 1lne con-fecting the point ofLpplIcation and the)Ilots hip joint,ilth the pilots;eat In 1ts meanlying POsitlonach force 1n samelrection parallelto the projection onthe airplane planef synsnetryof aItne connecting thepoint of applicat
29、ionand the pilots hipjoint, WIth thepilots seat In ltsmean flylng pos!t!onParallel to the pro-jection on the atr-plane plane of sym-metry of a 1lne con-necting the point ofappllcatlon and thepilots hlp jolrrt,w!th the pilotsseat In lts mean1andIng positionEach force in samedlrectlon parallelto the p
30、rojection onthe airplane planeof synsnetryof aIne connecting thepoint of applicationand the pilots hipjoint, with thepflots seat in Itsmean landing poslt!or6Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IAirplanecontrol-. - . .Flap, tab,stabilizers
31、poiler,alightinggear,arrestinghook, andWIng-foldingoperatingcontrolICockpitcentrol2Crankwheel,or leveloperatelby pushor pullforceSma11wheelor knobMIL-A-8865B(AS)TABLE 111. Pilot applied loads. - Continuedwless than whee1 or50 nor grip ofmore than crank or150 1everR = radiusin inches1 IDirection6.Any
32、 ange wtthln20” of plane ofcontrol133 inch-pounds if operated only by twlstlng100 Ibs if operated only by push or pull3.6.4 Reactions. Reactions to the loads specified In 3.6 shall beprovided as follows:a. Byb. BYc. Byd. Bythe control system stops OnY.the control system locks ponents specifically pr
33、ovided for reactng plot-applied oads.the Irreversible mechanism only, with the irreversible mechanism .locked with the control surface in all positions wltirln its Ilmltsof motion.e. By the attachments of the longitudinal control system to thecontrol surface horn only, with the cockpit longitudinal
34、control inall positions within its limits of motion.f. By the attachments of the lateral control system to either controlsurface horn only, with the cockpit lateral in all positions withinits mts of motion.g By the attachments of the directional control system to the controlsurface horn only, with t
35、he cockpit directional control in allpositions within Its limits of motion.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I MIL-A-8865B(AS)3.7 Tail-to-wind loads. Loads on ailerons, elevators, and rudder(s) shallbe those resulting from a 70-knot hor
36、izontal tatlulnd. The magnltude anddistribution of the aerodynamic forces shall be determined by a rationalanalysls approved by the acquisition activity, or alternatively, the load ateach station shall vary 11nearly from zero at the hinge llne to a maximumvalue at trailing edge which is proportional
37、 at each station to the chordlength aft of the hinge 1ine, and the resultlng moment shall beH = 16.5 CSwhere:H = hinge moments, foot-pounds.c = average chord length of control surface aft of hinge 1ine, feet.S = area of control surface aft of htnge 1ine, square feet.The direction of the resulting lo
38、ad, the position of the surface, and thelocation of reactions shall be as specified in Table IV.3.8 In-flight refuellng loads. The following specfffed loads apply forprobe-and-drogue and flying-boom types of in-f1ight refueling system.3.8.1 Probe and drogue system.3.8.1.1 W. The loads shall be those
39、 resulting from a closing speedof lo knots. The effective tielghtat the tip of the probe-!nzstshall be 100pounds (hose, fuel, coupling equipment, probe-mast).3.8.1.2 Gust. The loads including dynamic loads on the mast probe shal1be those resug from encountering a 30-fwt-per-second (fps)-EAS gust.The
40、 gust shall be considered to act at all positions from 0“ to 360” ina direction normai to the flight path.3.8.1.3 Probe and drogue loads. The design limit loads for the probe,other than the droge impact loads are 1000 pounds tension, 1000 pounds radial,and 2000 pounds compression. The tension and ra
41、dial loads shal1 act separat-ely, and alternately, shall act in combination.3.8.1.4 Tanker airplane. A hose load of 2,770 pounds shall be applied ina 160” cone about the normal trial axis,3.8.2 Flylng boom systems.3.8.2.1 Slipway and slipway doors. Air loads and other loads normallyimposed on the st
42、ructure shall be sustained by the slipway and its dcers inboth the open and closed positions, in addition to imDact loads imposed bycontact of the nozzle. Ultimate design loads shall be at least 2,000 poundslaterally and 5,000 pounds vertically.8Provided by IHSNot for ResaleNo reproduction or networ
43、king permitted without license from IHS-,-,-MIL-A-8865B(AS)1T.1 2Controlondition surface1 Lateral2i=3 Longi-tudinal45Directional6Lateral7 Ia Longi-tudinalTABLE IV. Tail-to-wind loads.aDown on each aileron-4-Neutral andunlocked .Down on either aileronand up on the other_ DownupRightLeftDown on either
44、 alleronand up on the otherup IAgainststopsLockedDownIRight ILeft I5 ILocation ofreactiont control stickw_hes! .9!.Q- At stopsAt locks3.8.2.2 Reception cou. The receptacle shall sustain the followingultlmate design loads:a, Emergency disconnect: A load of 2(7,000/COS A)at the nozzle universal In a d
45、irection at anglethe receptacle axis, where maximum A = 30In tension appliedA with respect tob. Transfer load: A load of 3(3,000/Cos B) in tension or compressionaPPlled at the nozzle universal, in a dlrectlon at angle B withrespect to the receptacle axis, where angle B varies between 0“and 17”, and
46、combined with a fuel pressure of 125 psi x 3.c. Contact load: A load of 20,000 pounds in compression applled at thenozzle unfversal in a direction at angle C with respect to thereceptacle axis, where the angle C varies between O“ and 17”.9Provided by IHSNot for ResaleNo reproduction or networking pe
47、rmitted without license from IHS-,-,-3.9 External stores.load factor of 1.5 for theMIL-A-8865B(AS)External stores shall be subjected to a verticalweiaht of a lBO-oound man standirm on the store orholding on to the store wlth”tfieairplaneswings folded. -3.10 Parachute brakes. For In-flight deployment
48、, the airspeed shall bethe limit speed in the landing conflguratlon, V, . For deployment aftertouchdown, the airspeed snail be 1.3 VS,. ,3.10.1 Steady load. The load shall be equal to the drag load at thespecified speed applled at all angles up to 15” from the flight path.3.10.2 Shock load. The load
49、 shall be 1.1 times the steady drag loadapplied along the fllght path axts.3.10.3 s. The load shall be the steady drag load In combination with a .2-fps-EAS gust applied normal to the flight path. After touchdown, onlylateral gusts shall be applied. The airplane attitude after touchdown shallbe all attitudes
