1、i MIL-R-38980A 10 I 979970b 0305889 4 - MIL-R-359 SOA (USAF) 25 March i970 Supersedes MIL-R-38980 (USAF) 12 November 1968 MILITARY SPECIFICATION. RACK, BON3 EJECTOR, AIRCRAFT BRU-4/A . =: AND RACK, BOHB EJECTOR, AIRCRAFT BRU-4A/A This specification is mandatory for use by USAF. 1. SCOPE This specifi
2、cation covers the requirements for two types of equipment designated as the Rzck, Bomb Ejector, Aircraft BRU-4/A and the Rack, Bomb Ejector, Aircraft BRU-4A/A, hereafter referred to as the rack, for carriage and release (either freefall or forced ejection) of stores up ;o the 5000 pound 2. APPLICABL
3、E DOCUIYENTS The following documents, of invitation for bids, form a specified herein. 2.1 SPECIFI(=ATIONS Federal PPP-C-843 Mi li t ary MIL-P-116 MIL-1)-1000 MIL-T-7743 MIL-L-10547 MIL-B -26 19 5 XIL-9-9858 *- class. the issue in effect on the date of part of this specification to the extent -. Cus
4、hioning Materiai, Cellulose i .-. :Preservation, Methods of Drawings, Engineering and Associated 9 Lists Testing, Store Suspension Equipment, General Specification for Liners, Case, Waterproof Boxes, Wood-Cleated, Skidded, Load- Bearing Base Quality Control System Requirements -. _. - . . I- :, . 1.
5、 . -. - FSC 1095 c .? THIS DOCVFMM CONTAINS dD PAGES. ir 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-38780A = MIL-R-389 80A( USAF) 2.2 STAh?AWS MIL-STD-129 MIL-STD-130 MIL-STD-143 MIL-STD-202 MIL-STD-785 MIL-STD-810 MIL-STD-831 MIL-STD-11
6、86 2.3 DRAWINGS Air Force 68513090 6 8 513 136 69 513400 (Copies of documents 10 0b 0305890 O Marking for Shipment and Storage Identification Marking of U.S. Military Property Specifications and Standards; Order of Precedence for the Selection of Test Methods for Electronic and Electrical Component
7、Parts Requirements for .Reliability Program (For Systems and Equipment) Environmental Test Methods for Aerospace and Ground Equipment Test Reports, Preparation of Cushioning, Anchoring, Bracing, Blocking, and Waterproofing; with Appropriate Test Methods Rack, Bomb Ejector, Aircraft BRU-4/AY Assembly
8、 of Wire Harness, Rack, Bomb Ejector, Assembly of Rack, Bomb Ejector, Aircraft BRU-4A/A, Assembly of required by contractors in connection with .- specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) 3. REQUIREMENTS 3.1 Qualificati
9、on. This specification makes provisions for preproduction testing . 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-3898OA LO m 9999906 0305891 2 W 3.2 Components 3.2.1 Selection of Materials. Specifications and standards of .all materials an
10、d parts, and Government certification and approval of processes and equipment which are not specifically designated herein and which are necessary for the execution of this specification, shall be selected in accordance with MIL-STD-143. 3.2.2 Weight Reduction. The contractor chail make evsry effort
11、 to hold to minimum the equipments over-all weight without impairing the function, operation or durability. All changes that are required to accomplish weight reduction shall be subject to written approval by the procuring agency prior to incorporation. 3.3 Design and Construction 3.3.1 The racks sh
12、all be constructed in conformance to drawing 68513090-7 (BRU-4/A), 69513400 (BRU-4A/A), and subsidiary drawings. 3.3.1.1 Precedence. In the event of any conflict between this specification and the drawings, the specification shall govern. 3.3.2 Interchangeability. All parts having the same number sh
13、all be directly and completely interchangeable with each other with respect to installation and performance. interchangeable from aircraft to aircraft. When parts are not inter- changeable, the criteria listed in MIE-D-1000 shall apply and new drawings shall be prepared as required. The racks shall
14、be completely 3.4 Performance. The racks shall be capable of suspending and releasing stores by means of a cartridge-actuated mechanism which shall allow either a freefall drop or forced ejection of all stores cp to the 5000 pound class having 14 or 30 inch lug spacing and a diameter between 10.70an
15、d 33 inches. horizontal, and other type bombing. The rack is designed for dive, . 3.4.1 Forced Ejection; When forced ejection of the store is desired, the velocity of store, reaction forces and the flight attitude of the store shall be controlled by orifices which are placed in the gas system and wh
16、ich meter the flow of gases to the ejection pistons. 3,4.2 Special Weapon Requirements 3.4.2.1 In-Flight Lock Provision. The racks shall contain a reversible in-flight locking mechanism which, when locked, will prevent weapon release even though the releasing force is generated in the releasing devi
17、ce. ., Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-R-38780A LO I 7777906 0305872 4 m - MIL-R-38980A(USAF) 3.4.2.2 positioa, no electrical energy shall be transmitted to the cartridge when a 28 volt potential is applied to the cartridge firin
18、g circuits and the hook release mechanism shall be restricted from operation by a mechanical block. In-Flight Lock Function. With the in-flight lock in the locked :* 3.4.3 of withstanding the stresses incurred when fired with the in-flight safety lock engaged without inadvertently releasing -the sto
19、re or damaging any structural part of the rack. when only one of the firing switches (S-1, S-3) is closed. Locked Shut and Sympathetic Firing. The racks shall be capable Both cartridges shall fire 3.4.4 Conventional Weapon Arming Control. The nose, center, and tail solenoid operated arming controls
20、shall operate from an 18 to 30 vdc power supply and shall each draw a maximum of 0.15 amperes continuously when energized at 24 vdc. and holding all standard arming wire loops. selectively capable of providing for an unarmed release or ejection, or armed release or ejection, of stores weighing from
21、100 to 5000 pounds Each control shall be capable of receiving . Each control shall be 3.4.5 Life. The racks shall function satisfactorily for 250 firings. 3.4.6 Reliability. The contractor shall initiate and maintain a reliability program in accordance with MIL-STD-785. be subject to modification by
22、 the procuring activity. This program shall 3.4.6.1 Reliability Levels. The following reliability levels shall be achieved and demonstrated by the .contractor: a. Inadvertent Release. With proper adjustment of the hook release mechanism, there shall be no inadvertent release during the design servic
23、e life of the racks (250 firings under service conditions). . b. Release Performance Requirements. With proper maintenance and replacement of parts as required per maintenance Tech Order, the achieved rate of failure shall be no failures in 250 releases under servic.e conditions, excluding cartridge
24、 failure. C. Reliability Failure. The bomb rack shall be constructed as specified herein and successfully complete the tests of paragraph 4.5, “Test Methods,“ of this specification with no failures as defined herein preventing satisfactory performance. Reliability of 98.0 percent for a 2-hour estima
25、ted mission time with Mean Time Between Failure (MTBF) value of 100 hours is required. Compliance will be acceptably demon- strated at 90 percent confidence level by 440 hours or more of total qualification testing time with no uncorrected failures. , 4 Provided by IHSNot for ResaleNo reproduction o
26、r networking permitted without license from IHS-,-,-3.5 Environmental Requirements. The racks shall be capable of proper operation during or after, as applicable, the following environmental conditions : a. Temperature from -53.9OC (-65OF) to f176.7OC (350OF). b. Humidity up to 95 percent, relative.
27、 ce Salt spray incident to use, storage or transportation near or on a large body of salt water. d. Icing conditions incident to service use. e; Sand and dust likely to be encountered under desert conditions. f. Vibration incident to flight, transportation and handling. g. Shock incident to flight,
28、transportation and handling. 3.6 Identification of Product. The racks and all component parts thereof shall be marked for identification in accordance with MIL-STD-130; 3.7 Government Furnished Property. When specified in the contract, the Government will furnish the following io the contractor, upo
29、n his request, for use in testing the Rack, Bomb Ejector, Aircraft BRU-4/A and the Rack, Bomb Ejector, Aircraft BRU-4AIA. Stock Number Description Item or of Number Part Number Item Quantity 1 1375-516-9924- . Cartridge, Bomb, As stated in M187 Ejection, CCU-9/B contract 2 Cartridge, Bomb As stated
30、in Ejection, CCU-lO/B contract 3 Cartridge, Bomb As stated in . Ejection, CCU-l/B contract 3.8 Workmanship. which will insure that the criteria of appearance, fit, smoothness of operation, and adherence to specified tolerances are observed. These criteria must apply to all accessories and to all ext
31、ernal nonfunctioning parts, such as nameplat assemblies shall be installed with a 0.025 minimum to 0.040 maximum inch diameter. spring-loaded, locked position, S-1 shall be actuated by manually closing its firing circuit. shall have fired. The rack hooks shall not unlatch and the store shall remain
32、suspended on the rack. After the Locked Shut and Sympathetic Firing Test, the rack shall be subjected to steps c., d., and e. of the Functional Test. Failure to meet these criteria or evidence of failure or permanent deformation of any structural part shall be cause for rejection. Locked Shut and Sy
33、mpathetic Firing Test. The racks shall be A 2000 pound simulated store Special overboard orifice The safety lock bell crank shall remain in the The rack shall be fired. Both cartridges 4.5.6 Reliability Life Test. Perform step b. of the Functional Test. After completion of step b., of the Functional
34、 Test, 100 releases of the 2000 pound simulated store shall be.performed at ambient tempera- ture with the fore and aft orifice pin assemblies having 0.111 inch diameters and 100 releases of the 500 pound simulated store with the fore and aft orifice pin assemblies having 0.093 inch diameters. CCU-l
35、/B cartridges shall be used in each of the above firings. one CCU-l/B, or CCU-9/B and one CCU-lO/B cartridge, or equal, 50 releases of a 100 pound simulated store shall be performed with the fore and aft orifice pin assemblies having 0.156 inch diameters. The two ejector pistons and the slave piston
36、 shall be removed from the rack, disassembled and cleaned after each 25 firings or at the end of each firing day, whichever occurs first. shall retract completely for the first five firings following each cleaning of the rack. After each fiftieth firing, orifice pin . assemblies, and all “0“ring.s i
37、n the slave and ejector piston assemblies shall be replaced. erosion which precludes satisfaction of the functional test shall be considered as meeting the operational life requirements of this specification. Evidence of such damage, wear, or erosion shall be cause for rejection. Two Using The two e
38、jector pistons Completion of this test without such damage or 4.5,7 Environmental Tests. During or after, as applicable, each environmental test, the racks shall be subjected to steps f., h. of the functional test. portions of the functional test shall be considered as failure to pass the environmen
39、tal tests and cause for rejection. g., and Failure to meet the requirements of these 15 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-387OA LO 777770b 0305704 7 MIL-R-3898OA(USAF) 4.5.7.1 High Tem erature. at 176.7OC (350F:; percent for four
40、hours. The temperature shall be reduced to mbieiit and the racks shall be fired five times as specified in the firing portion of the functional test and an inspection shall be made for gas leakage during the firings. In addition to the criteria in paragraph “4.5.7 Environmental Tests,“ edence of gas
41、 leakage shall be cause for rejection. The racks shall be raised to and held 4.5;7.2 Humidity. The racks shall be subjected to the humidity test described in procedure I, Method 507, MIL-STD-810. 4.5.7.3 Salt Fog. in accordance with MIL-T-7743. The rack shall be subjected to a salt fog test Paragrap
42、h 4.12 of MIL-T-7743 shall apply 4.5.7.4 Icing Conditions. The rack shall be stabilzed at 53.9“C (-65OF)Z percent, then subjected to 37.7“C (lOO“F)$ percent and 90 4 2 percent relative humidity until frost has disappeared. The racks shall then be stabilized at -53.9OC (-65OF)N percent. While the rac
43、ks are at this temperature, step f. of the-hnctional test shall be performed. exceed 450 inch pounds. 4.5.7.5 Sand and Dust. and dust test in accordance with procedure I, Method 510, MIL-STD-810. 4.5.7.6 Vibration. in accordance with procedure I, Method 514, MIL-STD-810, except that figure 3 of this
44、 specification shall be utilized in lieu of figure 514-1 of MIL-STD-810. All electrical circuits shall be monitored during this test. The vibration test shall be performed once with the racks in each of the following configurations: Force required for manual release shall not The racks shall be subj
45、ected to a sand The racks shall be subjected to a vibration test a. Rack, not loaded. b. Loaded, safety lock locked. (i) (2) With 250 pound simulated store installed. With 1000 pound simulated store installed. C. Loaded, safety lock unlocked. (i) With 250 pound simulated store installed. (2) With 10
46、00 pound simulated store installed. . - NOTE: 10.75 inches. The 250 pound simulated store shall have a minimum diameter of 16 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-flIL-R-3780A 10 7777706 0305705 9 XIL-II- 389 80A ( USAF) FIGURE- 3 RANGE CU
47、RVEFOR VtBRAlION YEST . -1 17 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. NIL-R-3ClOA 10 m 949790b 030570b O . In addition to the criteria of 4.5.7, the following shall be cause for rejection: -a. Malfunction of any part or circuit during the t
48、est. b. Failure of any part during the test. I 4.5.7.7 Shock. For this test, the maximum weight simulated store shall be the 2000 pound simulated store. Design loads shall be as illustrated in Table II. The rack shall be subjected to the yield load shock tests described in MIL-T-7743. This test shal
49、l be conducted with the inflight safety lock locked and repeated with the inf light safety lock unlocked. 4.5.8 Electrical Tests. completed, a complete electrical continuity and insulation resistance test of all circuits as shown in Drawing No. 68513136 shall be performed. with MIL-STD-202, Method 302, Test Condition A. Insulation resistance shall be greater than 100 megohms. be cause for rejection. NOTE: cleaned (see
