1、L, MIL-R-375bC LO E 7777906 0305540 -1 b MIL-R-38956C (USAF) 18 April 1973 SUPERSEDING MIL-R-38956B(USAF) 16 April 1969 MILITARY SPECIFICATION RACK, BOMB EJECTOR, AIRCRAFT mU-5O/A 1. SCOPE 1.1 Scope. ment designated as Rack, Bomb Ejector, Aircraft MAU-50/A, hereafter referred to as the rack, for car
2、riage and release (either freefall or forced ejection) of stores up to the 2000 pound class. This specification cwers the requirements for one type of equip- 2. APPLICABU DOCUMENTS 2.1 The following documents, of the issue in effect on the date of invitation for bids, form a part of this specificati
3、on to the extent specified herein. *SPECIFICATION Federal PPP-B-601 PPP-B-636 PPP-c-843 Military MIL-P-U MIL-D-1000 MI ET-774 3 MI L-Q-9858 1-45662 STANDARDS Military MIL-STD-O MIL-STD-l.2 9 MI ESTD-14 3 MI ESTD-202 MIL-STD-785 MI L-STD -810 Boxes, Wood, Cleated-Plywood Boxes, Shisping, Fiberboard C
4、ushioning Material, Cellulose Freservation, Methods of Drawings, Engineering and Associated IXsts Testing, Store Suspension Equipment, General Specification For Quality Control System Requirements Caiibrat ion System Requirements Marking for Shipment arid Storage Identification Marking of U.S. h5lit
5、ary Property Specifications and Standards; Order of Precedence for the Selection of Test Nethods for Electronic and Electrical Component Wrts Requirements for 3eliability Frogram (For Systems and Equipment ) Ehvironmental Test Kethods for Aerospace and round Euuipment THIS DOCUMENT CONTAINS With App
6、ropriate Test Methods DRAWINGS Air Force 643.320 Rack, Bomb Ejector, Aircraft M4U-50 Assembly Of 64513ii5 Electrical Assembly and Schematic Bomb Ejector Rack (Copies of specifications, standards, drawings, and publications required by suppliers in connection with specific procurement functions shoul
7、d be obtained from the procuring activity or as directed by the contracting officer.) 3. REQuIREMEms *3.1 Qualification. The racks furnished under this specification sbaL1 be products that have been tested and passed the qualification tests specified herein, and have been listed or approved for list
8、ing on the applicable quali- fied products list at the time set for opening of bids. 3.2 Components. 3.2.1 Selection of materials. Specifications and standards of aU. usterials and parts, and Government certification and approval of processes and equipment which are not specificaliy designated herei
9、n and which are necessary for the execution of this specification, shall be selected in accordance with 3.2.2 Weight reduction. The contractor shall make every effort to hold to a minimum the equipments overall weight without impairing the function, opera- tion or durability. All changes that are re
10、quired to accomplish weight reduction shall be subject to mitten approval by the procuring agency prior to incorporation, MIL-STD-143 3.3 Design and construction, 3.3.1 The rack shall be constructed in conformance to drawing 64513120 and subsidiary drawings . 3.3.1.1 Precedence. and the drawings, th
11、e specification shall govern. in the event of any conflict between this specification 3.3.2 and completely interchangeable with each other with respect to installation and performance . craft to aircraft. MIL-D-1000 shall apply and new drawings shall be prepared as required. Interchangeability. All
12、parts having the same number shall be directly The rack skias be completely interchangeable from air- When parts are not interchangeable, the criteria listed in 3.4 Performance. by means of a cartridge-actuated mechanism which shall allow either a freefall The rack shall be capable of suspending and
13、 releasing stores 2 Licensed by Information Handling ServicesMIL-R-375bC 10 7997906 03055q2 T I drop or forced ejection of all stores up to the 2000 pound class having 14 inch lug spacing and a diameter between 9.00 and 30 inches. for dive, horizontal, and other type bombing. 3.4.1 Forced ejection.
14、velocity of store, reactiori forces and the flight attitude of the store shall be controlled by orifices which are placed in the gas system and which meter the flow of gases to the ejection pistons. The rack is designed When forced ejection of the store is desired, the *3*4.2 Conventional weapon arm
15、ing control. The nose, center, and tail solenoid operated arming controls shall operate from an 18 to 30 vdc parer supply and shaU. each iOns, ex- cluding cartridge failure, C. Reliability failure, The bomb rack shall be constructed as specified herein and successfully complete the tests of paragrap
16、h 4.7, “est methods,“ of this specification with no lly advise the procuring activity of all defects likelyto be found and methods of correcting theme 4.5 Test conditions. test under “4.7 Test methods . I Each rack shall be subjected to the individual One sample shaU be selected at random by the qua
17、lity Prior to being sub- Sampling tests shall consist of the sampling tests When the sample rack fails to meet the specified The investigation of a test milure If so, the Test conditions shall be. as specified in each specific 4.6 Quality control requirements . a quality control system acceptable to
18、 the government for the equipment covered by this specification, with Specification MIL-e tensile strength of 160,000 psi. A 2000 pound simulated store as shown in Figure 1 shall be installed on the rack. each end of the rack shall be torqued to a total of 840 f 50 inch pounds, The torque shall be a
19、pplied incremently by turning each bolt of a set approximately the same number of turns. 4.7.3.1.2 Test procedure. the simultaneous imposition of loads for each condition along or about, as applicable, the axes shown in Figure 1. first be imposed inincrements of 10 per cent of design load until 100
20、per cent of design load is reached, then in increments of 5 per cent of design load until il5 per cent of design load is reached. at each per cent increment for three minutes before proceeding to the next per cent increment after 60 per cent of the design load is attained. loading shall not exceed 5
21、 per cent of the design lads per second, load of 115 per cent of design load has been reached and held for three minutes, the load shall be relieved to zero and the rack inspected. simulated store shall be manually released and the position of the rack in the fixture shall be reversed. permnent defo
22、rmation shall be cause for rejection. shown in Table II. The set of sway braces at The yield load test of the rack shall consist of For each condition the loads shall The loads shall be held The rate of When a The Test Set-up and procedures shall be repeated. Design loads shall be as 7 Licensed by I
23、nformation Handling Services14 INCH HOOKS CONDITION NUMBER P x lbs y Us z LBS !x IN-BS My In-Lbs MZ IN-LBS 1 2903 7200 16%) 13900 -104750 -80500 2 3590 6650 2400 i1650 -12- -74700 3 -2265 3880 -1070 48500 128000 48300 4 -1970 2820 -190 35200 117200 34800 4.7.3.2 Ultimate strength test, 4,7,3.2.1 Tes
24、t Set-up. for the YIELJ) LQAD TEST. The test Set-up for this test shall be as specified 4.7.3.2.2 Test procedure. yield load test up to U5 per cent of the design lad, except thatEtfter li5 per cent of the design load has been reached, loading shall continue in 5 per cent increments of the design loa
25、d up to 150 per cent of the design load, After 150 per cent of the design load has been reached and held for three minutes, the load shall be reduced to zero and the rack inspected. shall be tested in one direction only. including i50 per cent of design loads shall be cause for rejection. loads shal
26、l be as shown in condition 4 only of Table II. Test procedure shall be as specified for the The rack Design Any brea-kage during loading up to and 4.7.4 Functional test. the following procedures and in the order listed: Testing of the rack shall be performed as outlined in a. The rack shall be mount
27、ed on a test stand in a horizontal position with the hooks downward. bo A lo00 pound simulated store with standard Air Force Bomb Lugs on 14 The ground safety pin shall be fully inserted. inch centers and the center of gravity located midway between the lugs shall be suspended from the rack. Sway br
28、aces shall be torqued as required in the test Set-up suspension yield load test paragraph of this specification. removed and reinserted. Any movement of the hook linkage or rotation of the center bellcrank that prevents or restricts the removal or reinsertion of the ground safety pin shall be cause
29、for rejection. One ARD 863-1 and one 446-1 cartridge shall be inserted in the cartridge retainers (P/N 64Di3265) and installed in the breech of the rack. The retainers shall be screwed into the breech with a torque of 250 to 300 inch pounds. assemblies with a diameter of 0.062 inches shall be instal
30、led. With the ground safety pin removed., 28 f 4 volts E shall be applied to Hns B-C and the cartridges shall fire, The hooks shall open and the store shall be The ground safety pin shall be Forward and art orifice ph 8 MIL-R-3756C LO m 777970b 0305547 7 m 1 Licensed by Information Handling Services
31、- MIL-R-3875bC LO W 779990b 03055q8 O 9 I 9 Licensed by Information Handling ServicesI - MIL-R-3B75bC 10 0 777970b 0305547 2 forcible ejected, shall be a minimum of 8.2 feet per second. returned to their retracted position. the peak reaction.forces against the supporting structure shaU. be measured
32、and recorded for each piston. between 2.5 and 3.0 feet belar the suspended position shall be horizontal f 1-112 degrees. tool engaged in the square manual release socket located on the side of the rack containing the cartridge access to the breech and designated by the “Hook Manual Release“ presenta
33、tion. 35-80 inch pounds and smooth in oseration. The velocity of the store at the end of the piston stroke In all cases except individual tests, The ejector pistons shall have The flight attitude of the store at a position * C. The rack hooks shall be latched by clockwise rotation of a suitable Torq
34、ue required for this operation shall be * d. The hook mnual release shall be rotated in a counterclockwise direction. Torque required for this operation shall be 45 1 15 inch pounds. shall open and remain in. an opened position. The hooks * e. A standard arming wire for conventional weapons shall be
35、 installed in each of the mming controls. Using a convenient device, the force required to pull the arming wires installed in the arming solenoid shall be measured. This measurement shall be made twice for each arming contrai, once with the arming solenoid not engergized and once with the solenoid e
36、nergized, required forces shall be: The (i) Arming solenoid not energized: The arming control shall not release the arming wire when a force of 10 pounds is applied. wire when a force of 14 pounds is applied. The arming control shall release the arming (2) Arming solenoid energized: The arming contr
37、ol shall not release the arming wire when a force of 1.50 pounds is applied. * f. On the 64513120-5 rack, the store away switch shall actuate when the end of the plunger is at a point 1.50 inches minimum below the suspension surface of the hooks, actuation. indicate “store present I NOTE: the diamet
38、er tolerances Shan be those shown in the specific orifice tierL sub2ected to 37.7OC (-loo?!?) 24 per cent at 90 + 2 per cent relative k;unidity uiitil frust dis- appeared. The rack shall tkii be stPitr,iXzed at -53.9OC (-65C) 23 per cent. While the rack is at this teinyxeture, step d. ol the functio
39、nal tes3 shall be performed except thai; force required for manual. release shall not exceed 450 inch pounds. 4.7.7.5 Sund and dust. in accordance with Proceciure I, Eethod 51 O, EL-STD-G C. !?ne rack s1ia.l.l be siTajected. to e sanc. and dust tes% I 11 Licensed by Information Handling ServicesMIL-
40、R-3875bC 30 W 7797706 0305553 O W 1 %-4.7.7.6.1 flesonaiice search test. A frequency sieep shal be conducted in each I test axis to determine the resonant frequencies of the rack/store combination. The location of the point(s) on the surface of -Lhe store which experiences the meatesi vibratLon ampl
41、itude will be determined or each resonarnt frequency. The vibration of the store will be monitored and controlled at this ?oint(s) by a vibration pichp(s) oriented -Lo measure aaximurr! store motion during resonance dwell test. should be the miii5mun required to provide the necessary data. The vibra
42、tion amplitude uring the frequency sweep -%4.7.7.6.2 Resonance dwell test. The rack shall be subjected to a resonance I4ethod 514, Procedure I, Part I, Resonance dwell tesbs will be conducted in each dwell test in accordance with YJL-STD-810, except as specified herein. axis at each of the selected
43、resonan-L requencies. cation shall be utilized in lieu of the test curves of Figure 514.1 of FIL- STD-810. quencies which exhibit the greatest vibrat-ion amplilude. frequency wll be established at the appropriate resonant frequency. vibration amplitude will then be increased until the maximum mglitu
44、de measured at the monitor localion(s) equals the test curve value (Figure 2) for that frequency. The resonance dwell nil1 then be accoilished at %his amplitude and frequency. In the event that resonant frequency shifts as amplitude increases, the in-ut frequency will be established at the resonant
45、frequency at test am$itud.e. Fig-we 2 of this specifi- Testing in each axis shall be limited Lo the three resonant fre- The excitation The 4k.7.7.6.2. Test conditions. Dwell. tLme at eac3 resonance will be 30 minutes. Fifteeh minutes of dweE. toirie will be made r.B.-tii ;i?e rack safety locked and
46、tne remaining 15 rriinutes with the safe-ty lock unlocked. tests will be accomFlished 2% bo-Lh cif the follmig conclitions: The complete three axis b. Vitfi a 1000 pouid simulated store suspended fi-on: the Ib inch spacing shackles. Licensed by Information Handling ServicesI MIL-R-38956C (USAF) *4.7
47、.8 Electrical tests. After all preceding tests in 4.7 have been completed, a conrplete electrical continuity and insulation resistance test of all circuits as sham in Drawing 6413U.5 shall be performed, The insulation resistance test shall be in accordance with ML-STD-2Q2, Method 302, Test Condition
48、 A, Insulation resistance shail be greater than 100 megohms. tests shall be cause for rejection. Arming solenoids shal not be subjected to the insulation resistance test. Failure to pass these *4.7.8.1 Firing circuit continuity test. a. Insert ground safety pin into ejector rack to fuily engaged pos
49、ition. b. Apply 28 volts dc to pins B and C (pin N grounded) of rack connector. There must be no voltage present at breech firing pins. C. Retract ground safety pin to first detent and with 28 volts dc still applied to pins B and C, there must be 28 volts dc present at each breech firing pin. d. Remove ground safety pin from rack. NOTE: (see Section 6). After completion of the functional firing, the rack shall be cleaned 5. PmPARATION FOR DEI3VERY *5.l Levels A and Bo Each rack shall be cleaned and dried in accordance with applicable processes and procedu
