1、MIL-A-8863C(AS)19 July 1993SUPERSEDINGMIL-A-8863B(AS)6 May 1987.MILITARY SPECIFICATIONAIRPLANE STRENGTH AND RIGIDITYGROUND LOADS FOR NAVY ACQUIRED AIRPLANESThis specification is approved for use within the Naval Air Systems Command,Department of the Navy, and is available for use by all Departments
2、and Agencies ofthe Department of Defense.1. SCOPE1.1 Scope. This specification defines the strength and rigidity requirementsapplicable to land-based and ship-based airplanes for the following ground loadingconditions:a. Take-offs.b. Landingsc. Ground maneuvering.d. Ground handling.e. Supplemental l
3、oads.AMSC N/A Fsc 1510DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8863C(AS)2. APPLICABLE DOCUMENTS2.1 Government documents.2.1.1 Specifications and Standards.
4、The following specifications andstandards form a part of this specification to the extent specified herein.Unless otherwise specified, the issues of these documents shall be thoselisted in the issue of the Department of Defense Index of Specifications andStandards (DODISS), and supplement thereto, c
5、ited in the solicitation.SPECIFICATIONSMILITARYMIL-D-8708MIL-A-8860MIL-A-8867MIL-A-18717MIL-L-22589MIL-T-81259STANDARDSMIL-STD-2066Demonstration: Aircraft Weapon Systems,General Specification forAirplane Strength and Rigidity,General Specification forAirplane Strength and RigidityGround TestsArresti
6、ng Hook Installations, AircraftLaunching System, Nose Gear Type, AircraftTie-Downs, Airframe Design, Requirements forCatapulting and Arresting Gear Forcing Functionsfor Aircraft Structural Design(Unless otherwise indicated, copies of federal and military specificationsstandards, and handbooks are av
7、ailable from DODSSP - Customer Service,Standardization Document Order Desk, Building 4D, 700 Robbins Avenue,Philadelphia, PA 19111-5094.)2.2 Order of precedence. In the event of a conflict between the text ofthis specification and the references cited herein (except for associateddetail specificatio
8、ns, specification sheets or MS standards), the text of thisspecification shall take precedence. Nothing in this specification, however,shall supersede applicable laws and regulations unless a specific exemptionhas been obtained.3. REQUIREMENTS3.1 Weights. The design weights shall be as specified in
9、MIL-A-8860.3.2 Height distribution and center of gravity positions. Weightdistribution and center of gravity (CG) positions shall be all those that arecritical as defined by all possible arrangements of variable and removable -items for which provisions are required including all combinations ofpart
10、ially and fully loaded multiple bomb racks, internal fuel tanks, andexternal fuel tanks. In addition these arrangements shall include:2Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8863C(AS)a. The maximum internal fuel loading that can be att
11、ained within theapplicable design weight with all store stations empty of pylons,adapters, launchers, racks, and stores, and with other useful loadingssuch as passengers, cargo, guns and ammunition, etc, removed.b. All asymmetrical store loading configurations which result in thelesser of the follow
12、ing rolling moments:(1) 1.2 times the maximum rolling moment attainable by loading each-storestation, in turn, with all possible combinations of pylons,adapters, launchers, racks, and stores specified to be carried bythat store station in the detail specification. As each storestation is loaded all
13、other store stations shall be empty ofadapters, launchers, racks, stores, etc.(2) Maximum attainable by loading only one side of the airplane with theother side empty of adapters, launchers, racks, stores, etc.c. A tolerance of + 15 percent of the mean aerodynamic chord (MAC) or 15percent of the dis
14、tance between the most forward and the most aftactual values from the complete CG envelope, whichever is greater.This tolerance shall be applied so as to move the design CG forwardof the nest forward position and aft of the most aft position. Forairplanes with variable sweep wings, the reference MAC
15、 shall be forthe wings in the landing and take-off position.3.3 Limit and ultimate loads. With the exception of barricade loads, allloads specified herein are limit. The barricade loads are ultimate.3.4 Balance of forces. For conditions for which parameters or values ofparameters are not completely
16、specified to the extent necessary for the airplaneand Its components to be in complete translational and rotational equillbrium,additional forces which are determined by a rational method shall be assumed to actin a manner such that the acceleration of the airplanes component masses arebalanced by t
17、he externally applied forces. For the loading conditions specified in3.10 (except 3.10.1.6), 3.11.3 (except 3.11.3.5, 3.11.3.9 and 3.11.3.10), 3.14.1,3.14.2, 3.14.5, and 3.14.6, the externally applied forces and airframe responsesshall be determined by dynamic/flexible airframe analyses.3.5 Engine t
18、hrust. Unless specified otherwise herein, the values of enginethrust and/or power shall vary from zero to the maximum available.3.6 Types of airplanes. The types of airplanes are designated as follows:CB -Carrier-based airplanes Including carrier-based trainerairplanesLB - Land-based airplanes other
19、 than land-based trainer airplanesLBT - Land-based trainer airplanesSTOL -Airplanes having short field take-off and landing requirements3Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8863C(AS)VTOL - Airplanes having vertical take-off and land
20、ing requirementsSKI - CB, LB, LBT and STOL airplanes equipped with skis3.7 Arresting and catapulting forces. For carrier-based airplanes, thehorizontal components of the arresting hook and catapult tow forces shall bederived from MIL-STD-2066 or additional data provided in the detail specificationfo
21、r all the arresting gears and catapults with which the airplane is required tooperate.3.8 Variation in servicing of landing gear and tail bumper. For alltake-off and landing conditions the shock-strut air or gas pressure,shock-strut oil level, and tire pressure shall be all combinations of thefollow
22、ing variations:a. 15 percent above and 15 percent below the recommended air or gaspressure with the shock strut in the fully extended position.b. 15 percent above and 15 percent below the recommended oil volume.If the 15 percent above variation cannot be attained, the maximumattainable variation sha
23、ll be used.c. 20 percent above and 20 percent below the recommended tirepressure.These combinations shall include servicing instructions and ambienttemperatures (cold day to tropical day effects.3.9 Field roughness requirements. For field take-offs from, and landingsOR (a) unprepared sod, clay, or d
24、irt fields, (b semiprepared matted sod,clay, or dirt fields, and (c) paved runways, the roughness or range of terraincontours and soil-bearing strength for design shall be as defined on Figure1. The soil-bearing strength is given in terms of the California BearingRatio (CBR) and shall be constant up
25、 to a depth of at least one foot. Forboth the take-off and landing roll-out requirements the ground roughnesscontours for design shall be one minus cosine shaped undulations of constantwave length. uch undulations shall have all combinations of heights andlength specified on Figure 1. The shape of t
26、he undulations in the lateraldirection shall be held constant. The roughness for each type of airplaneshall be as follows:a. Paved runways - (CB, LB, LBT, and STOL.b. Semiprepared fields - CB and STOL.c. Unprepared fields - STOL.d. For SKI airplanes snow and ice covered semiprepared fields shallappl
27、y.3.10 Take-off.4Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8863C(AS)3.10.1 Catapult take-off. Applicable to carrier based airplanes. Thedesign loads for airplane accessories for catapult launching shall be inaccordance with this section.3
28、.10.1.1 Maximum deck reactions. The airplane design shall be such thatthe maximum landing gear vertical load for each landing gear unit separately,which results from the conditions of 3.10.1, shall not exceed the allowabledeck reactions determined from Figures 2 and 3. .3.10.1.2 Holdback loads. The
29、holdback loads shall be as specified herein.3.10.1.2.1 Buffing. The holdback bar shall engage the slider of thecatapult deck hardware at all critical angles resulting from the spottingrequirements of MIL-L-22589. During the buffer stroke, a tension load equalto the load H in 3.10.1.2.3 shall be appl
30、ied to the airplane holdback fitting.3.10.1.2.2 Tensioning. The airplane shall be secured to the catapultshuttle by the launch bar, and to the deck through the deck ramp structure bythe holdback bar, in all critical attitudes which occur during the tensioningoperation. The horizontal component of th
31、e tensioning force applied by thecatapult shuttle shall be 5,500 pounds and shall be reacted by the holdbackassembly.3.10.1.2.3 Release. The airplane shall be in all attitudes resultingfrom the release operation. The deflection of tires and shock struts shallcorrespond to the forces acting. The tens
32、ion load H, in pounds, at theairplane holdback Fitting shall be:Where:a. T = maximum thrust, with thrust-augmentation devices operating, ifairplane is so equipped, including surge effects from ignition, atsea level on a cold day, LB.b. W = maximum design weight, LB.c. 0 = angle between holdback axis
33、 and deck at release.d. The load in the launch bar shall be that required for equilibrium.The side loads shall be those resulting from the maximum possiblemisalignment of the launch system resulting from the off-centerpositions of MIL-L-22589.e. R = minimum release element load, LB.5Provided by IHSN
34、ot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8863C(AS)FIGURE 1. Ground roughness for landing and take-off6Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8863C(AS)FIGURE 2. Maximum allowable vertical d
35、eck reactionfor a landing - Catapult area.7Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8863C(AS)FIGURE 3. Dual wheel load factors for usewith figure 2 of 58Provided by IHSNot for ResaleNo reproduction or networking permitted without license
36、 from IHS-,-,-MIL-A-8863C(AS)3.10.1.2.4 Minimum release load. The minimum release load R, in pounds,for the release device shall be:The symbols are defined in 3.10.1.2.3. The allowable tolerance is plus 6andminus zero percent of the load R.3.1O.1.3 Maximum catapult tow force. For weights ranging fro
37、m themaximum design weight. to the weight required for the primary mission, thecatapult tow force shall be the maximum attainable at capacity operation fromall catapults from which the airplane is required to operate. For lesserweights, the tow force shall be reduced to that corresponding to the max
38、imumload factor of 3.10.1.4. The mean values of the tow forces of 3.7 shall beused to determine limit tow force.3.10.1.4 Maximum catapult horizontal load factor. The maximumquasistatic horizontal load factor of the airplane CG shall be the sum of themaximum attainable tow force corresponding to the
39、primary mission weight plusthe maximum horizontal component of thrust divided by the airplane weight forthe primary mission. For design of airframe structure, mass items and stores,the maximum horizontal load factor resulting from catapult launch shall bethat which is derivedfmm the flexible dynamic
40、 analysis.3.10.1.5 Catapult run. The catapulting loads resulting from allattainable attitudes throughout the catapult run and the off-center positionsof MIL-L-22589 shall be determined for all catapulting forces. The enginethrust shall be: (1) the maximum thrust with thrust augmentation devicesopera
41、ting if the airplane is so equipped; (2) Intermediate thrust; and (3)maximum continuous thurst. The effects of pretension loads, holdback releasecatapult stroke run, deck run, shuttle release, weight and CG variations shallbe included.3.10.1.6 Loading conditions prior to catapulting. The loads of th
42、isparagraph shall apply to the complete airplane while aft of the jet blastdeflector (JBD) and while maneuvering or waiting to be catapulted.3.10.1.6.1 Airplane configuration. The airplane configuration shall besuch that all movable control surfaces such as wire, fins, and othercomponents that can b
43、e moved while the airplane is on the deck, shall be intheir fully folded and unfolded, swept and spread, retracted and extendedpositions, and all intermediate positions. Unless the systems provided foroperating high-lift devices are so arranged that these devices can only be inthe retracted or neutr
44、al position before wing folding or unfolding, sweepingor spreading, etc., the high-lift devices shall be in the fully retracted,fully extended and all intermediate positions. Landing gear doors and weaponbay doors shall be in the fully opened position. Wing fuel and externalstores shall be all those
45、 that are critical.9Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-8863C(AS)3.10.1.6.2 Loads. The forces acting on the airplane shall be thoseresulting from the maximum attainable pressure in the hydraulic foldingsystem, or maximum attainable
46、system force If other than a hydraulic system isused, in combination with the following:Inertial forces, directed downward normal to the deck, that result ina load factor equal to 1.5.b. Inertial forces, directed downward normal to the deck, that result ina load factor equal to 1.5, and alternately
47、0.5, combined with aerodynamicforces which result from a steady wind over the deck having velocities fromzero to 60 knots from all horizontal directions, plus the superposition ofengine exhaust and/or thrust environment aft of the JBD defined as follows:(1)(2)The airplane positioned at all angles re
48、lative to the catapulttrack from a heading of directly into the JBD to + 90 of thisheading and at all positions aft of the JBD such that the nearestportion of the airplane is at all points laterally along the JBDand at all horizontal distances aft of JBD of 8 feet and greater,as measured from a vert
49、ical plane through the hingeline ofthe JBD.Another airplane positioned on the catapult in battery positionat all off-center positions of MIL-L-22589, with all enginesrunning at maximum power (afterburners and/or other thrustaugmentation devices operating). This other airplane shall bethe present airplane or shall be selected from the currentinventory of carrier-based airplanes, whichever produces the mo
