1、MIL-S-2737C Lb m 7777906 0147174 5 MIL-S-2939 8C (MC) 27 November 1984 SUPERSEDING MIL-S-293 98B (MC) 4 March 1983 MILITARY SPECIFICATION SLING SYSTEM, HELICOPTER: EXTERNAL CARGO, 40,000 POUND CAPACITY This specification is approved for use by U.S. Marine Corps, Department of the Navy, and is availa
2、ble for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers one type of adjustable cargo sling system used for lifting equipment and cargo by heli- copter. The sling system shall be capable of supporting external helicopter loads weighing u
3、p to 40,000 pounds. 2. APPLICABLE DOCUMENTS 2.1 Government documents. *2.1.1 Specifications, standards, and handbooks. Unless otherwise specified, the followinq specifications, standards, and handbooks of the issue listed in that issue of the Department of Defense Index of Specifications and Standar
4、ds (DoDISS) specified in the solicitation form a part of this specification to the extent specified herein. a SPECIFICATIONS FEDERAL QQ-P- 4 16 - Plating, Cadmium (Electrodeposited) PPP-B-601 - Boxes, Wood, Cleated Plywood PPP-B-636 - Box, Shipping, Fiberboard MILITARY MIL-P-116 - Preservation, Meth
5、ods of MIL-1-6866 - Inspection, Penetrant Method of MIL-1-6868 - Inspection Process, Magnetic Particle Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document shoud be addressed to the Commandant of the Marine Corps, Headquart
6、ers, U.S. Marine Corps (Code LMA-l), Washington, D.C. 20380, by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. a FSC 1670 THIS DOCUMENT CONTAINS /d PAGES Provided by IHSNot for ResaleNo reproduction or network
7、ing permitted without license from IHS-,-,-MIL-F-7190 - Forging, Steel, for Aircraft and Special Ordnance Applications MIL-A-8625 - Anodic Coatings, for Aluminum and Aluminum Alloys STANDARDS MILITARY MIL-STD-105 - Sampling Procedures and Tables for Inspection by Attribute MIL-STD-129 - Marking for
8、Shipment and Storage MIL-STD-810 - Environmental Test Methods and Engineering Guidelines *2.1.2 Other Government documents, drawings, and publications. The following other Government documents, drawings, and publications form a part of this specification to the extent specified herein. DRAWINGS U.S.
9、 Marine Corps 82 E2 82 50 29A0 O00 Sling, Multileg, Helicopter, External Lift, 5 O 29A1 O O O Apex Shackle Subassembly 5029A2000 Sling Leg 825029A3000 Grab Link 825029A4000 Chain Ley 825029A5000 Coupling Link 40,000-Pound Capacity 2.2 Other publications. The following document(s) form a part of this
10、 specification to the extent specified herein. The issues of the documents which are indicated as DoD adopted be the issue listed in the current DoDISS and the supplement thereto, if applicable. AMERICAN SOCIETY FOR TESTING AND MATERIALS ASTM A304 Alloy Steel Bars subject to end-quench hardenability
11、 requirements ASTM A322 Steel Bars, Alloy, Standard Grades ASTM D3951-82 Packaging, Commercial (Application for copies should be addressed to the American Society for Testing and ,Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103.) 2.3 Order of precedence. In the event of a conflict betw
12、een the text of this specification and the references cited herein, the text of this specification shall take precedence. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S- 29 3 98C (MC) 3. REQUIREMENTS 3.1 First article. The components from tw
13、o complete sling systems as described in 3.3 shall be submitted for first article examination and tests. Unless otherwise specified in the contract, first articles shall be manufactured using the same methods and under the same conditions and procedures intended for use on produc- tion units. The fi
14、rst articles shall be tested as specified in Section 4 to determine that, prior to starting production, the contractors production methods are capable of yielding sling system which meet the requirements specified herein. 3.2 Materials. Except as specified herein and on the applicable drawings and s
15、pecifications, materials shall be selected by the manufacturer. Materials selected shall be capable of meeting the performance requirements specified herein. *3.3 Design and construction. The sling system shall consist of one apex shackle subassembly, four sling legs, four grab links, four coupling
16、links, and four chain legs manufactured in accordance with Drawing No. 825029A0000 and this specification. The sling system shall be fabricated, assembled, and stowed in accordance with the drawings and specifications specified herein. No deviation from the prescribed dimensions or tolerances is per
17、missible. The sling system shall conform to Drawing No. 825029A0000. Seventeen compon- ents shall make up a complete sling system; one apex shackle, four Kevlar Aramid Fiber, or equal chain legs, four coupling links, four grab links and four chain legs. “3.3.1 Apex shackle subassembly. The apex shac
18、kle subassembly shall act as an interface between the Kevlar Aramid Fiber, or equal, sling legs and the helicopter hook. “3.3.2 Sling legs. Each sling leg shall be 3-strand, made of Kevlar Aramid fiber, or equal, and shall be of a “wire-rope“ con- struction as shown in Drawing No. 825029A2000. Each
19、of the three strands shall have a braided dacron, or equal, jacket and the rope shall be covered with polyolefin, or equal, shrink tubing. The eye splices, as described in Drawing No. 825029A2000, shall be covered with shrink tubing and dacron, or equal, sock, then coated with a waterbased adhesive
20、emulsion. *3.3.3 Grab links. The grab links shall be connected to the Kevlar Aramid Fiber, or equal, sling legs. The coupling links specified in Drawing No. 825029A5000 shall be connected to the grab links which shall be connected to the chain legs specified in Drawing No. 825029A4000. The free ends
21、 of the chain legs shall be passed through or around the load pickup points and secured by the grab links. The length of each chain leg shall be adjustable to the loads requirement. The working length of the chain leg depends on which chain link is secured by the grab link. 3 Provided by IHSNot for
22、ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S- 2939 8C (MC) “3.3.4 Couplinq link. A coupling link shall serve as the inter- face between each grab link and chain leg. be as specified in Drawing No. 825029A5000. The coupling links shall *3.3.5 Chain leg. The chain l
23、eg specified in Drawing No. 825029A4000 shall serve as the interface between the load to be lifted and the coupling link specified in 3.3.4. *3.4 Performance. The sling system described herein shall provide capability to suspend and transport cargo internally beneath cargo helicopters. The sling sys
24、tems are used with single, dual point, or multipoint suspension helicopters. may be configured to converge to single hooks or be separated in various ways between fore, aft and center helicopter hooks. 3.4.1 Load capacity. The sling system (four legs) shall have a safe working load of 40,000 pounds.
25、 Reducing the number of legs in the rigged configuration reduces the maximum load capability of the sling system in direct proportion to loss of legs. only leg is used in suspending the total load, the maximum allowable single leg load may be increased by a factor of 1.4 to 14,000 pounds. When rigge
26、d, the sling legs shall not exceed 45 degrees from a verticle center line projected through the helicopter hook. Various numbers of lifting legs However, when “3.4.2 Load strength. The sling system components shall sustain up to the following loads in compliance with first article test and productio
27、n sampling requirements and shall conform with the quality assurance requirements specified in Section 4. U 1 tima te Sling System Cafe Breaking Component Reference Working Proof Strength Assemblies Drawing Load i/ (lbs) Load 2/ (lbs) Load 3/ (lbs) Apex Shackle 825029A1000 40,000 100,700 151,200 Sub
28、assembly Sling Leg 825029A2000 10,000 39,800 59,800 Grab Link 825029A3000 10,000 39 , 800 59 I 800 Chain Leg 825029A4000 5 I 000 19,900 29 , 900 Coupling 825029A5000 5,000 19 , 900 29,900 Link i/ Safe workinq load. Maximum load weight that component is rated to lift. 21 proof load. Maximum working t
29、ensile load of component 3/ Ultimate breakinq strength load. Maximum working tensile during standard lifting operations. loadmultiplied by a. safety factor of 1.5. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S- 29398C (MC) *3.4,3 Setting of
30、 the shrink tubinq. Heat shall be applied to L shrink tubing of each sling leg while under a 23,700-pound load, O 3.4.4 Environmental. Unless otherwise specified herein, the sling system shall meet the performance requirements specified herein after exposure to environmental conditior,s as follows:
31、3.4.4e1 Temperature. 3.4-4.1.1 Storage. The sling system shall withstand storage temperatures from -48OC (-55OF) to +74*C (+165OF) and.thereafter meet the requirements specifiedin 3.4. *3.4.4.1.2 Operatinq. The sling system shall be capable of meeting the requirements specified in 3.4 at any tempera
32、ture from 32OC (-25OF) to 52OC (+12SF). This requirement will not be teste but is provided tu assist in material selection. 3.4.4.2 .Humidity. Thesling system shall withstand relative humidity up to 95 percent as specified in MIL-STD-810, method 507, procedure 1 and thereafter shall meet the require
33、ments specified in 3e4. *. *3,5 Weiqht. The weight of a complete sling system, one apex shackle subassembly, 4 sling legs, 4 coupling links, 4 grab links, and 4 chain Xegs, shall not exceed 170 pounds, 3.6 Markinq, Major components described in 3.3 shall be marked for identification as shown on appl
34、icable drawings. . 3.7 Workmanchip. The workmanship and finish shall beof suffi- ciently high grade to assure satisfactory operation consistent with the requirements of the specification and applicable drawings. All parts used in the sling system shall be free of burrs, sharp edces, chips and foreig
35、n matter. The standards of workmanship exhibited in any approved first article, subject to any qualifications stated in the Governments notice of approval, shall be demonstrativeof the requirements of the cuntract relative to workmanship insofar as nat specifically covered by applicable specificatio
36、ns. 0 4. QUALITY ASSURANCE PROVLCIONS “4 . 1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, the contractor is responsible for . the performance of all inspection requirements as specified herein. Except as otherwise specified in the contract or purchase
37、order, the contractor may use his own or any other facilities suitable for the eisapproved by the Government. -I performance of inspection requirements specified herein, unless The Governmer,t reserves the right L- a. -5 1 f Provided by IHSNot for ResaleNo reproduction or networking permitted withou
38、t license from IHS-,-,-. MIL-S-293 9 8C (MC) to.perform.any of the inspections set forth in the specification. where such inspections are deemed necessary to assure Chat supplies and services conform to the prescribed requirements. 4.2 Classification of inspection. The inspection requirements - -2 C
39、. Quality Conformance (see 4.5) ,. . 4.6. and 4.7.;. Failure of any component to pass any of the tests shall be cause for rejection of the sling system. article, shall be at the manufacturers rick. tion;lot: of 50 ox less sldng systems which have passed the examina- tion of 4.6, a random sample shaL
40、1 be selected in accordance with MIL-STD-105, acceptable quality level (AQL) 6.5, level II, and the . components.shal.1 be subjected to the applicable tests specified in 4.7. Failure of any component to pass the tests specified in 4.7. shall cause acceptance of the sling system, and the inspection l
41、ot from which the,system was selected, to be withheld untillthe Eollow- :ing have .been. completed: Further production of :sling systems by the manufacturer, prior to approval of the first *4.4 Production inspection samples. From each succeeding inspec- b, Take the necessary action, with the concurr
42、ence of the pro- curingsactivity to correct or eliminate the failure from all units from those units previously shipped. .in the inspection lot and, if 50 directed by the procuring activity, 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-a QIL-S-2
43、93 9 8C (MC) n Table I. Examination Classification Defect Major Minor Test Materials Design Cleanliness Workmanship Assembly e Component dimensions Cadmium plating Anadking - Keeper spring torque Identification X Any part not fabricated of specified material X Any characteristic not ir! accordance w
44、ith specified requirements x Dirt, grease, oil, or foreign matter .x Burrs, sharp edges, surface roughness, loose construction broken rovings, frayed rope assembly, loose or torn shrink tubing, ends of eye sock not serviced. x Part missing, not assembled or joined as specified, Operation specified.
45、omitted or not performed as X Perpendicularity, parallelism, concentricity, out of specifiec? tolerance. Out of “Unless otherwise specified“ tolerance. X X Evidence of hydrogen embrittle- mentt unable to document specified baking after plating per QQ-P-416 Not as specified in-MIL-A-8625 Out of toler
46、ance at specified angular positions X X X Not as specified on component .* -I I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-2939C 16 W 9999906 04L7417 I . MIL-S-29398C (MC) M 4.5 Quality conforna”nce examination. Each sling system shall be
47、e - subjected to the visual examination in 4.6 and the tests of 4,7.3, Inability of the sling system or component to pass the examination of 4.6,and tests of 4.7.3 shall constitute a failure, . formance to the material and workmanship requirements specified in Table I. 4.6 .Examination. Each sling s
48、ystem shall be examined for con- 1i 4.7 Tests. - *4,7.1 Test conditions. Unless otherwise specified herein, the sling system shall be subjected to inspection and test under the following conditions: a, Temperature Room ambient +27+8OC (80+15OF). b, Relative Humidity , , Room ambient up to 95 percent
49、, c. Altitude Normal ground atmosperic pressure of 760 +50mm (30 + 2 inches) of mercury. 4.7.2 First article and production sample inspections, The first article and production sample sling system components shall be cub- jected to the following tests after satisfactorily passing the tests and examination specified in 4.6 and 4.7.3. a 4.7.2-1 Test procedurefor sling system components. Subject the W sling system component
