1、 Comments, suggestions, or questions on this document should be addressed to: WR-ALC/GRVEB, Robins AFB GA 31098-1813. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at https:/assist.daps.dla.mil . AMSC N/A FSC 16
2、70 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. INCH-POUND MIL-DTL-25959G SUPERSEDING 22 November 2011 MIL-DTL-25959F 19 January 2007 DETAIL SPECIFICATION TIE DOWN, TENSIONERS, CARGO, AIRCRAFT This specification is approved for use by all Departments and Agencies
3、 of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers two types of aircraft cargo tie down tensioners and excludes cargo chains. The tie down tensioners are considered to be an aircraft Critical Safety Items (CSI). Type I (10,000 lbs) and Type II (25,000 lbs) cargo chains are
4、governed under MIL-DTL-6458 and are procured separately from the tie down tensioners in this specification. 1.2 Classification. Tie down tensioners covered by this specification are one of the following types (see 6.4): Type I 10,000 pounds capacity DELETED Style A MB-1 Style B CGU-4/E Type II 25, 0
5、00 pounds capacity DELETED Style A MB-2 Style B CGU-3/E Type III 10,000 lbs capacity, MB-3/E Type IV 25,000 lbs capacity, MB-4/E Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25959G 2 1.3 Part or Identifying Number (PIN)M 25959- III . PINs
6、to be used for aircraft cargo tie down tensioners acquired to this specification are created as follows: Type Specification number Prefix Type Capacity Government designation III 10,000 lbs MB-3/E IV 25,000 lbs MB-4/E 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are spec
7、ified in sections 3, 4, or 5 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned t
8、hat they must meet all specified requirements of documents cited in sections 3, 4, or 5 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this document
9、 to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-DTL-6458 Chain Assemblies, Single Leg, Aircraft Cargo Tie Down DEPARTMENT OF DEFENSE STANDARDS MIL-STD-130 Identificati
10、on Marking of U.S. Military Property MIL-STD-810 Environmental Engineering Considerations and Laboratory Tests MIL-STD-882 System Safety MIL-STD-889 Dissimilar Metals (Copies of these documents are available online at https:/assist.daps.dla.mil/quicksearch/ or from the Standardization Document Order
11、 Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25959G 3 2.2.2 Other Government documents, drawings, and publications. The following other Government documents, drawings, a
12、nd publications form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. SD-6 Provisions Governing Qualification 2.3 Non-Government publications. The following documents form a part of this
13、 document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. AMERICAN SOCIETY FOR QUALITY (ASQ) ANSI/ASQ Z1.4 Sampling Procedures and Tables for Inspection by Attributes (Copies of this document are available fro
14、m www.asq.org or the American Society for Quality, 600 North Plankinton Ave., Milwaukee WI 53203-2914 or www.ansi.org or the American National Standards Institute, 25 West 43rdSt., 4thFloor, New York, NY 10036) 2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the event o
15、f a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Qualification. Tie down tension
16、ers furnished under this specification shall be products that are authorized by the qualifying activity for listing on the applicable qualified products list before contract award (see 4.1 and 6.5). 3.2 Tie down tensioner description. Tie down tensioners shall be simple one-handle release mechanisms
17、, lightweight, and as compact as possible. The tie down tensioners shall be used in conjunction with the Type I and Type II chains as specified by MIL-DTL-6458 to increase/decrease the tension being applied to the chain. They shall be of rugged construction so that they can withstand the rough handl
18、ing encountered in installation and service. 3.3 Design and construction. The tie down tensioners shall be designed and constructed so that no parts will work loose in service. They shall be built to withstand the strains, jars, vibrations and other conditions incident to shipping, storage, installa
19、tion and service. They shall be weatherproof and designed to prevent the intrusion of water and sand into critical operating components. There shall be no sharp corners or other stress risers which would tend to cause cracks with repeated use under normal operating conditions. The tie down tensioner
20、s shall be constructed so as not to cause injury to operating personnel. 3.3.1 Materials and protective coatings. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25959G 4 3.3.1.1 Recycled, recovered, or environmentally preferable materials. R
21、ecycled, recovered, or environmentally preferable materials should be used to the maximum extent possible provided that the material meets or exceeds the operational and maintenance requirements and promotes economically advantageous life cycle costs. However, used, rebuilt, or refurbished items sha
22、ll not be provided. 3.3.1.2 Protective coatings. Materials that deteriorate when exposed to sunlight, weather, or operational conditions normally encountered during the service life (see 3.3.5) of the item shall not be used or shall have means of protection against such deterioration that does not p
23、revent compliance with the performance requirements specified herein. Protective coatings that chip, crack, or scale with age or extremes of climatic conditions or when exposed to heat shall not be used. Fasteners, handles, and fittings used in the assembly of the item shall also be treated with the
24、 proper corrosion preventatives. 3.3.1.3 Dissimilar metals. Dissimilar metals, as defined in MIL-STD-889, shall not be in contact with each other. Metal plating or metal spraying of dissimilar base metals to provide electromotively compatible abutting surfaces is acceptable. The use of dissimilar me
25、tals only when separated by suitable insulating material is permitted, except in systems where bridging of insulation materials by an electrically conductive fluid can occur. Sealants or gel type gasket materials shall be used between faying surfaces and butt joints. 3.3.2 Markings. Equipment, assem
26、blies, and parts shall be marked for identification in accordance with MIL-STD-130. The contract number, contract date, date of manufacture, contractor part number, national stock number (NSN), and classification are mandatory. The tie down tensioner shall be marked to indicate the maximum service l
27、oad rating specified in 3.9.4. These markings shall be permanent. 3.3.3 System safety. The design of the tie down tensioner shall not contain any hazards that can result in a category greater than medium as defined in Table A-IV of MIL-STD-882. The tie down tensioner shall be functional without shar
28、p edges or burrs that might injure operational personnel or prevent the operation of the tie down tensioners in restricted locations. Operation of the tie down tensioner shall not present undue hazards to personnel during tie down of cargo, while the cargo is secured, during the release of cargo res
29、traint, or during removal or stowage of the tie down tensioners. Tie down tensioners shall be capable of being released using only one hand to allow the tie down tensioner to be released in an emergency situation. Normal operation shall not present cutting, pinching, stabbing, nor abrupt impact haza
30、rds to personnel or present a tearing hazard to chemical/biological personal protective gear. 3.3.4 Fastening devices. All screws, bolts, nuts, pins, and other fastening devices shall be properly designed, manufactured, and installed with adequate means of preventing loss of torque or adjustment. Co
31、tter pins, lock washers, or nylon patches shall not be used for this purpose, except for the attachment of trim items or as provided in commercial components. The protrusion of a bolt through each nut shall have at least two threads showing and not more than five threads showing from all angles the
32、bolt can be viewed from. 3.3.5 Service life. The tie down tensioner shall be designed for a minimum service life of 30 years. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25959G 5 3.3.5.1 Damage resistance. The tie down tensioner shall be
33、designed such that frequent dropping onto a concrete runway shall not render the tie down tensioner inoperable when tested as specified in 4.6.8. 3.4 Environmental conditions. 3.4.1 Operating temperature range. The tie down tensioner shall be capable of operating in ambient temperatures ranging from
34、 -65 oF to 160 oF when tested as specified in 4.6.4.1 and 4.6.4.2. 3.4.2 Storage temperature range. The tie down tensioner shall be capable of being stored in ambient temperatures ranging from -65 oF to 160 oF when tested as specified in 4.6.4.1 and 4.6.4.2. 3.4.3 Solar radiation. The tie down tensi
35、oner shall not be adversely affected by full-time exposure to solar radiation, such as those conditions encountered in desert environments. 3.4.4 Salt fog. The tie down tensioner shall be capable of storage and operation in salt laden, sea coast environments without damage or deterioration of perfor
36、mance when tested as specified in 4.6.4.3. 3.4.5 Sand and dust. The tie down tensioner shall be capable of storage and operation during exposure to wind-blown sand or dust without damage or deterioration of performance when tested as specified in 4.6.4.4. 3.4.6 Vibration. The tie down tensioner shal
37、l be capable of withstanding vibrations encountered during use in all cargo transportation aircraft, including all modifications of the C-5, C-17, C-130, KC-10, and all other cargo transporting aircraft when tested as specified in 4.6.4.5. 3.5 Weight and dimensions. The overall weight of the MB-3/E
38、shall not exceed 3.3 lbs and the overall weight of the MB-4/E shall not exceed 5.8 lbs when tested as specified in 4.6.5.1. The dimensions of the tie down tensioners, including the space through which levers and other mechanisms move, shall not exceed envelope sizes as shown in Table I when tested a
39、s specified in 4.6.5.2. TABLE I. Tie down tensioner dimensions. Tie down Length Width Height MB-3/E 15 inches 4 inches 3.5 inches MB-4/E 18 inches 5 inches 4 inches 3.6 Tensioning capabilities. 3.6.1 Tensioning ability. After preliminary adjustment of the tie down tensioner to remove excess slack in
40、 the chain, the tensioning assembly shall be operational and shall be capable of applying tension to the chain of not less than 300 lbs with a manually applied torque of not more Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25959G 6 than 6
41、0 inch-pounds acting on the tensioning adjustment control. Additionally, no component of the tie down tensioner shall fail when torques up to 85 inch-pounds are applied to the tensioning adjustment control, in the tensioning direction while the tie down tensioner is fully retracted, and in the loose
42、ning direction, when in the fully extended position when tested as specified in 4.6.6.1. Failure is defined as catastrophic as well as permanent deformation of components. The tensioning adjustment control shall have a minimum height of 1 inch. It shall be of circular design with raised area to aid
43、grip during tensioning and shall have at least eight locking positions per 360orotation. 3.6.2 Tension releasing. The tie down tensioner shall be so designed such that the chain assembly (component attached to the cargo) can be manually released and automatically separated from the tie down tensione
44、r with one hand in a single operation with an applied force not exceeding 50 lbs while restraining loads that apply 5,000 lbs of tension on the chain. It shall also be possible by the application of additional force not to exceed 100 lbs (for both Types III and IV devices) to safely release the chai
45、n assembly from the tie down tensioner while restraining loads that apply 10,000 lbs of tension for the MB-3/E device or 25,000 lbs for the MB-4/E device when tested as specified in 4.6.6.2. Any release mechanism which results in any component of the tensioning assembly becoming detached or damaged
46、or does not permit the tie down tensioner to be immediately reapplied shall not be acceptable. The tie down tensioner shall be capable of releasing sufficient tension for the chain to be released in a safe manner solely by using the tension release mechanism. The mechanism shall be designed in such
47、a manner that inadvertent release of the mechanism by personnel moving about the aircraft does not occur. Any design which requires operating personnel to exercise extreme caution in releasing the tie down tensioner under the proof loads cited in this specification shall not be acceptable. 3.7 Compo
48、nents. Installed cargo tie down tensioner assemblies consist of a chain assembly, conforming to MIL-DTL-6458, attached to a tie down tensioner as follows: a. Type I chain assembly with MB-3/E b. Type II chain assembly with MB-4/E 3.7.1 Tensioning assembly. The tensioning assembly adjustment shall be
49、 capable of quickly providing any adjustment within the range of 0 to at least 3.5 inches for the MB-3/E, and 0 to at least 4.5 inches for the MB-4/E tie down tensioner device. Preliminary adjustment of the tie down tensioner length shall be accomplished as specified (see 3.7.1.2). Final adjustment of the tie down tensioner length shall be provided by a take-up in the tensioning assembly itself. 3.7.1.1 Ring attachment
