1、MIL-R-25085C 10 = 777790b 0304380 5 i MIL- R- 2 508 5C (USAF) 3 June 1959 Superseding MfL-R-25085B(USAF) 1 November 1957 MILITARY SPECIFICATION RACK, BOMB, AIRCRAFT, ELECTRIC, TYPE MB-3A 1. SCOPE 1.1 This specification establishes the requirements for one type of 30 inch lug span, 24V dc bomb rack,
2、designated Type MB-3A and designated for use with stores weighing up to and including 5000 pounds. 2. APPLICABLE DCuMENTS 2.1 The following documents, of the issue in effect on the date of invitation for btds, form a part of this specification. SPECIFICATIONS Federal QQ-P-416 PPP-B-585 PPP-B- 591 PP
3、P-B-601 PPP-B-621 PPP-B- 636 PPP-T-60 Mi 1 it ar y MIL-P-116 MIL-B-138 MIL-6-3278 MIL-PSO28 MU-E-5272 CI. . Plating, Cadmium (Electrodeposited) Boxes, Wood, Wirebound Boxes, Fiberboard, Wood-Cleated Boxes, Wood, Cleated-Plywood Boxes, Wood, Nailed and Lock-Corner Boxes, Fiber Tape; Pressure Sensitiv
4、e Adhesive, Waterproof-For Packaging and Sealing Preservation, Methods Of Boxes, Wood, Fiberboard-Lined For Overseas Shipment (For Weight Contents Not Exceeding 500 Pounds) Low and High Temperatures) Of Manufacturers (For Production Aeronautical and Associated Equipment) Environmental Testing, Aeron
5、autical and Aesociatzd Equipment, General Specification For Grease; Aircraft and Inltruments (For Drawings and Data Lists: Preparation ,- THIS DOCUMENT CONTAINS 18 PAGES. FSC 1095 M W MCORP. DAYTON.OHI0 500 - _- l!/ Preparation Of MIL-L-10547 Liners, Case, Waterproof Soldering Process, General Speci
6、fi- STANDARDS Militaty MIL-STP 129 MIL-STD-130 M.3 3 58 6 Marking for Shipment and Storage Identification Marking of U. S. Metals, Definition of Dissimilar Military Property Air Force-Navy Aeronautical AN3102 AN3106 DRAWINGS U. S. Air Force 56 522785 Connectors - Electrical, Receptacles, Connectors
7、- Electrical, Plugs, Box Mounting Straight Rack Assembly - Bomb, Electrically Operated, 5000 Pound Capacity, Type MJ3-3A PUBLICATIONS Air Force-Navy Aeronautical Bulletin 143 Specifications and Standards; Use Of (Copies of documents required by contractors in connection with specific procurement fun
8、ctions should be obtained from the procuring accivity . .e or as directed by the contracting officer.) L. . 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-HIL-R-2 508 5C (US AF) 3. REQUIREMENTS 3.1 Preproduction.- This specification makes provisio
9、ns for pre- production testing. 3.2 Selection of specifications and standards.- Specifications and standards for necessary commodities and services not specified herein shall be selected in accordance with ANA Bulletin 143. 3.3 Materials 3.3.1 Protective treatment.- When materials are used in the co
10、n- struction of the rack that are subject to corrosion in salt air or other atmospheric conditions likely to occur during service usage, they shall be protected against such corrosion in accordance with QQ-P-416 . Acceptance or approval of material in the course of manufacture shall in no case be co
11、nstrued as a guarantee of the acceptance of finished product. the I MIL-R-25085C 10 S 79Ob 0304382 7 I/ 3.3.2 Metals.- Metals shall be of the corrosion-resistant type or suitably treated to resist corrosion due to fuels, salt spray, or atmospheric conditions likely to be met in storage or normal ser
12、vice. 3.3.3 Dissimilar metals.- Unless suitably protectd against electrolytic corrgsion, dissimilar metals shall not be used in intimate contact with each other. Dissimilar metals are defined in Ms33586. 3.4 Design and construction.- The design and construction of tha bmb rack shall conform to Drawi
13、ng 56522785 and this specification. 3.4.1 Soldering.- Soldering required in the fabrication of the rack shall be in accordance with MIL-S-6872. 3.4.2 Welding.- Any welding required in the fabrication of the rack shall be in accordance with MIL-W-6858. 3.4.3 Springs.- Care shall be exercised in the t
14、reatment of springs to prevent methods of manufacture which will result in brittle- ness. To prevent brittleness as a result of plating, all springs shall be treated in accordance with the applicable detail drawing. 3.5 Performance 3.5.1 Shock.- The bomb rack shall not function inadvertently when su
15、bjected to shock tests specified in 4.6, Test Methods. I 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ML-R-25085C (USAF) 3.5.2 Vibration.- The bomb rack shall be capable of satisfaat#rp operation in accordance with 3.6 during and after the vibra
16、tion tests described In 4.6.12. 3.5.3 Temperature.- The bomb rack shall be capable of satisfactoryr operation in accordance with 3.6 throughout the temperature range of -6SF to f 1600F. 3.5.4 Lubrication.- The bomb rack shall operate satisfactorily without lubrication. If an initial lubrication is n
17、ecessary in the sealed units, lubricants shall conform to MIL-G-3278 or MIL-L-7870. 3.5.5 Xanual operation.- Means shall be provided for easy cocking and releasing of the rack with or without a store installed. 3.5.5.1 Cocking force.- A force of no more than 40 pounds shall be required to hand cock
18、the rack. 3.5.5.2 Tripping force.- A force of no more than 7 pounds shali be required to trip the rack when a total load of 40,000 pounds is applied . 3.5.6 Arming mechanism.- When the bomb rack is cocked, the arming wire retainers shall allow the inrerted and held in place. When the rack is release
19、d with the arming solenoid energized, the arming wires shall be retained by the solenoid plungers, Upon de-energization of the solenoid (see figure i), the arming wirer shall be releared with any dead load up tn and including 3 poundr. No load ehall be required to reease the wide8 when the rack i8 r
20、eleared with the solenoids un-energized. the solenoide energized io known as “armed“ release. Release with the solenoide un-energized is known as “safe“ release. arming wire swivel loops to be Rack release with 3.6 Electrical charazterietics 3.6.1 Voltage.- The bomb rack shall fulfill all the operat
21、ing - requirements a8 epecified herein when rupplied any voltage from 18V to 28V dab 3.6.2 Current 3.6.2.1 The currant drain of the releara solenoid shill not axoerd 6 amperes at 248 dc, at a room temperature of approximately 58OF (200C) . The current drain rhall be measured with the solenoid instal
22、led in the bomb raak. 4 PROBLEM HARD COPY e Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-25085C LO 7777706 0304384 2 3- a 5 I d- nl Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.6.2.2 The
23、 current drain of the arming solenoids shall not exceed 0.55 ampere at 24V dc, at a room temperature of approximately 680F (200C). The current drain shall be measured after the solenoid has been energized for 2 minutes and while it is installed in the bomb rack . 3.6.3 Time of release.- Rot more tha
24、n 0.030 second shall elapse from beginning of electrical impulse through release of circuit “B“ in figure 1 to the instant when bomb carrying hooks begin to open. 3.6.4 Time of transfer.- During operations of release circuit “B“ in figure 1, the time from the end of the electrical impulse to the com
25、pletion of transfer into the next rack release circuit shall be a maximum of O .O30 second. 3.6.5 Release impulse.- The release mechanism shall operate using a release impulse duration of 0.020 second or less. impulse of 0.020 second, the combined time of release and transfer shall not exceed 0.075
26、second. The above time tests shall be conducted using 18V dc, supplied to the rack and a room temperature of approximately 68OF (2OOC). measured from the beginning of the release pulse until a pulse indicating the completion of transfer is obtained through the “C“ terminal of the bomb rack. With a r
27、elease The combined time of telease and transfer shall be MIL-R-2505C LO rn 7777906 0304385 4 rn 3.6.6 Jettison release circuit.- There shall be a separate release circuit (jettison) in paralled to the normal release circuit, by means of which the rack can be released independently of the normal rel
28、ease circuit. This circuit shall be euch that, immediately upon opening of the hooks, the impulse required to release the rack is transferred to a jettison release output wire, possible to release several racks with one impulse. With this circuit, it shall then be 3.7 Interchangeability.- All parts
29、having the same manufacturers part number shall be functionally and dimensionally interchangeable. The drawing number requirements of MIL-D-5028 shall govern changes in the manufacturer s part nurcbers. 3.8 Weight.- The weight of the rack shall not exceed 22 pounds, 3.9 Identification of product.- E
30、quipment, assemblies and parts * shall be marked for identification in accordance with MIL-STD-130, 3.10 Workmanship.- The bomb racks shall be uniform in quality and material, of high quality workmanship, and free of any injuriws defects. 6 f- I Provided by IHSNot for ResaleNo reproduction or networ
31、king permitted without license from IHS-,-,-MIL-R-250CC 10 m 997970b 030L138b b 3.10.1 Cleaning.- Each rack shall mechaniam and rack housing shall be ent be re MIL-R-25085C (USAF) thoroughly cleaned, and the y free of loose particles such as dirt, metal chips, loose bits of wire and solder, etc. 3.1
32、0.2 Sand blasting.- All parta which are sand blasted shall be thoroughly cleaned to remove sand and grit. 4. QUALITY ASSURANCE PROVISIONS 4.1 Unless otherwise specified herein the supplier is responsible for the performance of all inspection requirements prior to submission for Government inspection
33、 and acceptapce. the supplier may utilize his own facilities or any commercial laboratory acceptable to the Government. and tests shall be kept complete and available to the Government as specified in the contract or order. Except as otherwise specified, Inspection records of the examinations 4.2 Cl
34、assification of tests.- The inspection and testing of the M3-3A bomb rack shall be classified as follows: a. Preproduction tests b. Acceptance tests 4.3 Preproduction testing 4.3.1 Preproduction test sample.- When so specified in the contract; a minimum of 4 bomb racks skll be tested at a laboratory
35、 designated by thg procuring activity, or, when so specified in the contract, at the contractors plant under the supervision of the procuring activity. It is not required that all tests be conducted on any one test sample. 4.3.2 Preproduction tests.- Preproduction tests shall consist of all tests de
36、scribed under 4.6, Test Methods. 4.3.2.1 Racks subjected to tests described under 4.6.10.1 shall The entire internal linkage of the rack shall be treated as follows. be sprayed with a liquid mixture consisting of 8 ounces of Dow Corning DC-4 or DC-4A Slicon Compound, which conforms to MIL-1-8660, an
37、d 1 pint of methylene chloride. After being sprayed, the rack shall be permitted to dry for 24 hours prior to conducting these tests. 4.4 Acceptance tests.- Acceptance tests shall consist of: a. Individual tests b. Periodic sampling tests Provided by IHSNot for ResaleNo reproduction or networking pe
38、rmitted without license from IHS-,-,-MIL-R-25085C LO W 9999906 0304387 8 W MIL-R- 2 508 5C (USAF) 4,4.1 Individual tests.- Each bomb rack shall be subjected to the following tests as described under 4.6, Test Methods, in the same order: a. Examanation of product b. Functional tests c. Shock test d.
39、Proof test 4.4.2 Periodic sampling tests.- Racks to be subjected to Y3ampling Tests“ shall be selected at random from production units which have successfully completed all individual tests. Sampling tests shall con- sist of all tests described under “Test Methods“, excluding 4.6.10.1.2, 4.6.10.2, 4
40、.6.10.3, 4.6.10.4 and 4.6.11. Racks shall be selected in the following manner: a. Not less than 1 nor more than 4 racks from the first 100 production units on the contract or order. b. Not less than 1 nor more than 4 racks from each succeed- ing 250 units or fraction thereof on the contract or order
41、. 4.4.2.1 Rejection and retest.- When one rack fails to meet the specification, acceptance of all racks on hand will be withheld until the extent and cause of failure are determined. After corrections have been made, 611 necessary tests shall be repeated. 4.4.2.2 Individual tests may continue.- For
42、operational reasons, individual tests may be continued pending the investigation of a sampling test failure. But final acceptance of the racks on hand or produced later shall not be made until it is determined that the racks meet all the requiremente of the specification. 4.4.2.3 Periodic test saopl
43、es.- Racks shall be subjected to tests in such a manner as to conserve sample racks. that all tests be conducted on any one rack. It is not required 4.5 Test conditions .- Unless otherwise specified, tests required by this specification shall be made under normal ambient conditions at approximately
44、68OF. 4.6 Test methods 4.6.1 Examination of product.- Each rack shall be inspected for conformance to the drawing and specification with respect to material , workmanship, dimensione, and markings. 8 h. R i E, Provided by IHSNot for ResaleNo reproduction or networking permitted without license from
45、IHS-,-,-_ I MIL-R-25085C LO 7779706 030q388 T 4.6.1.1 Workmanship inspection.- Each part of assembly shall be inspected for the existence of any of the conditions specified bei-w. The occurence of any one of the following conditions shall be sufficient reason for rejection: a. b. C. d. e. f. h. i. j
46、. k. 1. m. Dirty or pitted electrical contact points Dirt, metal, chips, filings, solder or burrs on any surface Visible lubrication Parts not treated for corrosion resistance Loose conneccions, badly soldered joints or frayed ends of wires Possible short circuiting because of proximity of bare wire
47、s or switch pasts to metal portions of the rack Play in levers and latches which may permit accidental release because of side slip or misalignment Loose rivets, screws, or pins Improper matehing of contact points on electrlcal switehes in both the cocked and released position Misalignment of parts
48、Insufficient clearance between moving parts and the case Clearance of openings through whieh dust may enter vital parts Presence of moisture or liquids 4.6.1.2 Detailed inspection of critical items.- Extensive experi- mental tests have proved that if any one of Che following unsatisfactory conditons
49、 exist, failure of the bomb rack will result after a short period of usage: a. Each bomb rack shall be inspected to insure that the wire cable leading from the receptacle into the solenoid and switch housing can in no way, under any condition, interfere with the operation of the arming device. b. Each bomb rack shall be cairefu1l.y inspected to insure that the 0.406 0,001 inch hole in the brass bushing of the solenoid a
