ARMY MIL-DTL-9401 C-2003 CANOPY PARACHUTE RING SLOT GENERAL SPECIFICATION FOR CONSTRUCTION OF《遮篷 降伞和环槽的建造常规》.pdf

1、 Beneficial comments (recommendations, additions, deletions) and any pertinent data that may be of use in improving this document should be addressed to: Natick Soldier Center ATTN: AMSSB-RAD-AD(N), Natick, MA 01760-5017, using the Standardization Document Improvement Proposal (DD Form 1426) appeari

2、ng at the end of this document or by letter. AMSC N/A FSC 1670 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. INCH-POUND MIL-DTL-9401C 12 May 2003 SUPERSEDING MIL-C-9401B 9 January 1968 DETAIL SPECIFICATION CANOPY, PARACHUTE, RING SLOT, GENERAL SPECIFICATION FOR CO

3、NSTRUCTION OF This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers the general construction requirements of a parachute canopy which is characterized by concentric rings of cloth separated from each other b

4、y slots and designated as the ring slot parachute canopy. 1.2 Classification. The classification of parachute assemblies are defined as part numbers as specified in the acquisition requirements (see 6.2). 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are cited in sections

5、 3 and 4 of this specification. These lists do not include documents cited in other sections of this specification or those recommended for additional information or as examples. While every effort has been made to ensure the completeness of these lists, document users are cautioned that they must m

6、eet all specified requirements documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications and standards. The following specifications and standards form a part of this document to the extent herein. Unless otherwise speci

7、fied, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DoDISS) and supplement thereto, cited in the solicitation (see 6.2). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,

8、-MIL-DTL-9401C 2 SPECIFICATIONS FEDERAL A-A-59291 - Ink, Marking (For Parachutes and Other Textile Items) V-T-295 - Thread, Nylon STANDARDS DEPARTMENT OF DEFENSE MIL-STD-849 - Inspection Requirements, Definitions and Classification of Defects in Parachutes (Unless otherwise indicated, copies of the

9、above specifications, standards, and handbooks are available from the Standardization Document Order Desk, 700 Robbins Avenue, Building 40, Philadelphia, PA 19111-5094) 2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherw

10、ise specified, the issues of the documents that are DoD adopted are those listed in the issue of the DoDISS cited in the solicitation. Unless otherwise specified, the issues of documents not listed in the DoDISS are the issues of the documents cited in the solicitation. AMERICAN SOCIETY FOR TESTING

11、AND MATERIALS (ASTM) ASTM D 737 Test Method for Air Permeability of Textile Fabrics ASTM D 6193 Standard Practice for Stitches and Seams (Application for copies should be addressed to the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.) 2.4 Order

12、of precedence. In the event of a conflict between the text of this document and the references cited herein (except for related associated specifications or specification sheets), the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulation

13、s unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 First article. When specified (see 6.2), a sample shall be subjected to a first article inspection in accordance with 4.2. 3.2 Materials. Materials shall conform to the requirements of the applicable Technical Data Package (TDP), t

14、o subsidiary specifications and standards applicable thereto and as specified herein. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-9401C 3 3.2.1 Thread. Unless otherwise specified, the thread used in the construction of the canopy shall co

15、nform to types I, II or III, class A of V-T-295. The color and size of the thread shall be as specified in the TDP. 3.2.2 Color. The color of webbing and tapes in fully concealed seams shall be optional except the color red shall not be used. 3.2.3 Recycled, recovered, or environmentally preferable

16、materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible provided the materials meet or exceed the operational requirements, and promote economically advantageous life cycle costs. 3.3 Construction. Details of construction shall be in acco

17、rdance with the TDP and the additional requirements as specified herein. 3.3.1 Assembly aids. Drilling, notches, stapling, basting or any other such techniques used as aids in the manufacturing process shall be kept to a minimum and the use thereof shall be restricted to the same limitations as mark

18、ings (see 3.3.1.2). All assembly aids, such as staples, shall be removed during or after assembly. For Navy procurements, hot glues are not authorized as an assembly aid. 3.3.1.1 Basting. Basting requirements shall be as specified in the TDP or be in accordance with common industry practices. Bastin

19、g stitches shall not be seen in the finished seam or assembly. Contractors unfamiliar with commercial practices shall contact the contracting officer for specified details prior to assembly of the item. 3.3.1.2 Assembly markings. Markings on the canopy, riser and other components as an aid to assemb

20、ly and to indicate stitching patterns shall be accomplished in a manner that will not adversely affect the utility, strength, or appearance of the parachute. 3.3.2 Warp direction. The warp direction of the canopy material shall be parallel to the skirt reinforcement band (seams) unless otherwise spe

21、cified in the TDP. 3.3.3 Reinforcement bands. The ends of the reinforcement band shall overlap a minimum of 4 inches unless otherwise specified in the TDP. The rows of stitching shall be continuous across the overlap. 3.3.4 Skirt reinforcement. The ends of the skirt reinforcement shall overlap a min

22、imum of 6 inches unless otherwise specified in the TDP. The rows of stitching shall be continuous across the overlap. When more than one piece is used, the shortest length shall cross a minimum of four gores. 3.3.5 Vent reinforcement. The ends of the vent reinforcement shall overlap a minimum of 4 i

23、nches unless otherwise specified in the TDP. The rows of stitching shall be continuous across the overlap. The lap joint shall be located so that the ends of the overlap will be secured by the Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-9

24、401C 4 stitching of at least two consecutive vent lines. The material for the vent reinforcement shall be one continuous piece. 3.3.5.1 Vent lines. Unless otherwise specified in the TDP, the vent lines shall be of the same material as the suspension lines. 3.3.6 Stitching. Stitching shall conform to

25、 ASTM D 6193. Unless otherwise specified, the stitch type shall be 301 of ASTM D 6193. The number of stitches per inch shall be as specified in table I. Table I. Thread size and stitches per inch Straight stitching Zigzag stitching Thread Size Type 301 Type 401 Type 304 Single throw Type 308 Double

26、throw E 1/ 7 to 11 1/ 7 to 11 2/ 12 to 16 2/ 8 to 12 F 1/ 7 to 11 2/ 12 to 14 2/ 7 to 10 FF 1/ 6 to 9 7 to 11 2/ 12 to 14 2/ 7 to 10 3-cord 5 to 8 - 2/ 4 to 6 5-cord 4 to 6 - 2/ 3 to 5 6-cord 4 to 6 - 2/ 3 to 5 1/ Stitches not exceeding 16 stitches per inch will be acceptable for a length not exceed

27、ing 2 inches in any one place with a minimum distance between locations of 12 inches. More than 16 stitches per inch will be cause for rejection. Where abrupt changes in material thickness occur, a variation of 2 stitches per inch beyond the specified number for a distance not exceeding inch shall b

28、e acceptable. 2/ When the material thickness is more than doubled, the width of the zigzag stitching may vary 50 percent or the number of stitches may vary + 2 stitches per inch beyond the number specified for a distance not exceeding inch. 3.3.6.1 Tension. The tension of the bobbin and the needle t

29、hreads shall be equal so that the thread locks will lie as close as possible in the center of the layers below the surface. Needles of multiple-needle machines shall be adjusted to provide the same tension from each needle insofar as practicable. 3.3.6.2 Straight stitching. Except for stitching made

30、 with stitch type 401, straight stitching shall be backstitched not less than inch, unless turned under in a hem or held down by other stitching. Unless otherwise specified in the detail specification, the outside row of stitching made with a multiple-needle machine shall be 1/8 1/16 inch from the e

31、dge of the seam or the material. Multiple rows of straight stitching, when specified in the detail specification, shall be distributed equally across the seam when a single-needle machine is used. Stitching made with stitch type 401 shall be properly and carefully locked where the stitching ends. Pr

32、ovided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-9401C 5 3.3.6.3 Zigzag stitching. Zigzag stitching that is parallel to straight stitching shall normally not overlap the straight stitching. When only one row of zigzag stitching is specified, it

33、shall be centered. Unless otherwise specified, the tolerance for the length of the row of zigzag stitching shall be + or 0 inch. The distance between the nearest edge of the zigzag stitching and the edge of the material or seam and the distance between the adjacent edges of the rows of zigzag stitch

34、ing on the drag surface shall be not less than 1/8 inch. 3.3.7 Automatic sewing machines. Automatic sewing machines may be used for sewing stitch patterns provided that the size of the pattern, the thread size, and the number of stitches per inch specified in the detail specification are maintained.

35、 A minimum of three tie-in, overlapping or back stitches shall be used to secure the ends. 3.3.8 Seams. Seams shall conform to ASTM D 6193. Seams shall be flat and smooth to preclude pleating, ragged edges, cloth edges not properly caught, and puffiness of fabric between. Every effort shall be made

36、to produce a fully folded flat seam. Excessive puffiness in the seams shall not be acceptable, because it tends to reduce the fullness in the rows of the stitching gores causing stresses in the seams during canopy inflation which may cause damage or failure. Finished fell and hem seams showing raw e

37、dges shall be repaired. Seam margins that are less than 1/16 inch, but not beyond the edge of seam or material, will be acceptable for a distance of 2 inches spaced not less than 36 inches apart. 3.3.9 Splices. Splices of webbing tapes, and ribbons used in assembling the canopy, except the vent rein

38、forcement web, shall be held to a minimum and shall not exceed the number specified in table II. Only one piece of webbing shall be used in the vent hem. When two or more layers of the same material are used in a seam, one layer shall be continuous across the splice of the other layer. Unless otherw

39、ise specified, the ends of the splice shall be made by overlapping the ends for a dis tance of not less than 4 inches. Table II. Number of Splices Length of seam (inches) Number of splices permitted Number of repairs permitted 0 to 2 0 0 2 to 12 0 1 12 to 72 0 2 72 to 240 1 3 240 to 360 2 4 360 to 4

40、80 3 5 480 to 600 4 6 Over 600 1 per 120 inches 1 per 100 inches Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-9401C 6 3.3.10 Repairs. 3.3.10.1 Broken or skipped stitches. Broken or skipped stitches in stitch type 301 shall be repaired by a

41、djacent stitching with the stitches extending a minimum of 3 inches ( 1 inch) beyond the ends of the stitches being repaired. Broken or skipped stitches in stitch type 304 or 308 shall be repaired by adjacent stitching with the stitches extending a minimum of three stitches beyond the ends of the st

42、itches being repaired. Broken or skipped stitches in stitch type 401 shall be repaired with stitch type 301 and as specified for broken or skipped stitches in stitch type 301. The frequency of the stitching repairs shall not exceed the number specified in table II. 3.3.10.2 Run-offs. A run-off shall

43、 be repaired by stitching within the seam margin tolerance with the stitches extending a minimum of 1 inch or three stitches, as applicable to the type of stitch, from the start and the end of the run-off. 3.3.10.3 Less than specified number of stitches per inch. Where the number of stitches per inc

44、h is less than the number specified, repairs shall be made by adjacent stitching, with the repair extending either 1 inch or three stitches, as applicable to the type of stitch, beyond the end of the repair. 3.3.10.4 Loose stitches. Loose stitching shall not be removed but shall be reinforced by adj

45、acent stitching. Loose stitches shall be interpreted as those that do not lie smoothly on the fabric when the seam is put under tension. 3.3.10.5 Tight stitches. Tight stitches shall be removed and the section shall be restitched. Tight stitches shall be interpreted as those that cause the fabric un

46、der the stitches to gather or pucker when the seam is put under tension. 3.3.11 Darning tears and cuts. Darning shall be held to a minimum. Holes (see 6.4) not exceeding inch in diameter and linear tears or cuts not exceeding inch may be darned. The darned area of linear tears or cuts shall form a r

47、ectangular pattern extending inch beyond each side and each end of the cut or tear. All darns shall be neat and flat and shall not pucker the canopy cloth. The darning thread shall be size A thread or yarns from the canopy and shall match the canopy cloth. 3.3.12 Measuring operations. 3.3.12.1 Cloth

48、. All cloth shall be measured and cut while under substantially no tension. Tightly rolled material shall be relaxed by unrolling and, if necessary, relaxing it for 24 hours to permit the material to return to its original state. Section pattern shall be carefully placed on the cloth so that the sma

49、ll inequities of various cloth widths (within the tolerance specified) are evenly distributed on each side of the pattern. When multiple layers of cloth are cut at the same time, extreme care shall be taken to prevent the cloth from slipping during any part of the cutting operation. 3.3.12.2 Suspension and vent lines. The suspension and vent lines shall be measured und