1、/- MIL-S-44071 4 m 777770b 0447550 b m I I I P MIL-S-4409 1 - 30 - November - - 1982 SUPERSEDING (See 6.5) MILITARY SPECIFICATION STRAP, CHIN, GROUND TROOPS - PARACHUTISTS HELMET This specification is approved for use by all Departments and Agencies of the Department of Defense. 1, SCOPE 1.1 -I_ Sco
2、pe. This document covers requirements for a chin strap. 2. APPLICABLE DOCUMENTS 2.1 Government documents. Unless otherwise specified, the following documents of -_-I_ - - -_. - .- the issue in effect on date of invitation for bids or request for proposal, form a part of this document to the extent s
3、pecified herein. SPECIFICATIONS FEDERAL UU-P-268 - Paper, Kraft, Wrapping PPP-B-636 - Boxes, Shipping, Fiberboard STANDARDS MILITARY MIL-STD-105 - Sampling Procedures and Tables for Inspection by Attributes MIL-STD-129 - Marking for Shipment and Storage MIL-STD-147 - Palletized Unit Loads MIL-STD-11
4、88 - Commercial Packaging of Supplies and Equipment - - - - - - -. - - Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Natick, MA 01760 by using the self-addressed Standardization Document Impro
5、vement Proposal (DD Form 1426) appearing at the end of this document or by letter. US Army Natick Research and Development Laboratories, FSC 8470 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-44091 DRAW1 NG US ARMY NATICK RESEARCH AND DEVELOP
6、MENT LABORATORIES 2-1- 1400 - Strap, Chin, Ground Troops - Parachutists Helmet (Copies of documents required by manufacturers in connection with specific acquisition functions should be obtained from the contracting activity or as directed by the contracting officer.) 2.2 Order of precedence. In the
7、 event of a conflict between the text of this - document and the references cited herein, the text of this document shall take precedence 3 REQUIREMENTS 3.1 -_- Guide sample. Guide samples, when furnished, are solely for guidance and information to the contractor (see 6.3). Variations from this docu
8、ment may appear in the sample in which case this document shall govern. 3.2 First article. When specified, a sample shall be subjected to first article inspection (see 4.3, 6.2 and 6.4). 3.3 Materials and components. Materials and components shall be as specified on Drawing-OO. 3.4 Construction. The
9、 construction shall conform in all respects to Drawing 2-1-140and as specified herein. 3.4.1 Stitching. All stitching shall be as specified on Drawing 2-1-1400 and as specified herein. 3.4.2 - Thread tension. Thread tension shall be maintained so that there will be no loose stitching resulting in lo
10、ose bobbin or top thread, or excessively tight stitching resulting in puckering of the materials sewn. The lock shall be embedded in the materials sewn. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3 c MIL-S-94091 9 m 7997706 0447552 T m MIL-S-4
11、4091 3.4.3 Repairs of type 301 stitching. Repairs of type 301 stitching shall be as ( follows: a. When thread breaks or bobbin run-outs occur during sewing, the stitching shall be repaired by restarting the stitching a minimum of 1/2 inch back of the end of the stitching. b. Thread breaks, two or mo
12、re consecutive skipped or runoff stitches noted during inspection of the item (in-process or end item) shall be repaired by overstitching. The stitching shall start a minimum of 1/2 inch in back of the defective area, continue over the defective area and continue a minimum of 1/2 inch beyond the def
13、ective area onto the existing stitching. stitching shall be repaired by removing the defective stitching, without damaging the materials and restitching in the required manner. 1/ - i/ When making the above repairs the ends of the stitching are not required to be backstitched. Loose or excessively t
14、ight - 3.4.4 Automatic stitching. Automatic machines may be used to perform any of the required stitch patterns provided the requirements for the stitch pattern, stitches per inch, size and type of thread are met, and at least three or more tying, overlapping or back stitches are used to secure the
15、ends of the stitching. 3.4.5 Thread ends. All thread ends shall be trimmed to a length of not more than ( 1/4 inch. 3.4.6 Fusing of ends of nylon webbing. as specified on Drawing 2-1-1400. be capable of providing sufficient heat to provide a smooth edge. the webbing yarns shall be fused together. A1
16、1 ends of nylon webbing shall be fused The apparatus used to fuse the webbing ends shall The cut ends of 3.4.7 Setting of eyelets. Holes for setting eyelets in nylon webbing shall be prepunched and shall be smaller than the outside diameter of the eyelet barrel so that the barrel must be forced thro
17、ugh the hole. The eyelets shall be securely clinched without cutting the adjacent material. splits in the eyelet or washer barrels. There shall be no more than two 3.4.8 Setting of snap fasteners. A hole shall be prepunched to receive the button and eyelet components.of the snap fasteners. The hole
18、shall be smaller than the outside diameter of the button and eyelet barrels so that the barrel must be forced through the hole. The hole shall not be punched in the setting operation with the button or eyelet barrel. cutting the adjacent materials and no more than two splits shall occur in the butto
19、n or eyelet barrels. The fasteners shall be securely clinched without Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-44091 4 m 9997906 0447553 1 m MIL-S-44091 3.4.9 Repairs. Except as otherwise specified herein, repairs are not allowed to be m
20、ade to the chin strap. 3.4.10 Replacement of defective components. During the spreading, cutting and manufacturing process, components having material defects or damages that are classified in 4.4.3 shall be removed from production and replaced with non-defective and properly matched components. 3.5
21、 Workmanship. The finished chin strap shall conform to the quality of product established by this document. applicable acceptable quality levels. The occurrence of defects shall not exceed the 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection. Unless otherwise specified in the contra
22、ct 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 order, the contractor may use his own or any other facilities suitable for the performance of the inspection requireme
23、nts specified herein, unless disapproved by the Government. inspections set forth in the document where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements. The Government reserves the right to perform any of the 4.2 Classification of inspectfon.
24、The inspection requirements specified herein are classified as follows: a. b. Quality conformance inspection (see 4.4). First article inspection (see 4.3). 4.3 First article inspection. When a first article is required (see 6.2), it shall be examined for the defects specified in 4.4.3 and 4.4.4. def
25、ect shall be Cause for rejection of the first article. The presence of any 4.4 Quality conformance inspection. Unless otherwise specified, sampling for inspection shall be performed in accordance with MIL-STD-105. 4.4.1 Component and material inspection. In accordance with 4.1, components and materi
26、als shall be inspected in accordance with all requirements of referenced documents unless otherwise excluded, amended, modified or qualified in this document or applicable purchase document . 4.4.2 In-process inspection. Inspection shall be made at any point or during any phase of manufacturing oper
27、ation to determine whether operations or sub-assemblies are accomplished as specified. Whenever nonconformance is noted, corrections shall be made to the parts affected and lot in-process. Parts which cannot be corrected shall be removed from production. 4 Provided by IHSNot for ResaleNo reproductio
28、n or networking permitted without license from IHS-,-,-h MIL-S-4407L 4 W 7777906 O447554 3 W I MIL-S-44091 4.4.3 End item visual examination. The end item shall be examined for defects listed below. sample unit shall be one complete chin strap. The inspection level shall be II and the acceptable qua
29、lity level (AQL), expressed in terms of defects per hundred unite, shall be 2.5 for major defects and 10.0 for total (major and minor combined) defects . The lot size shall be expressed in units of one chin strap. The Classification Examine Defect Major Minor Webbing Any hole, cut, or tear Not firmi
30、y or tightly woven; Any end of nylon webbing not edge frayed or scalloped fused Strap, left lower Any bartack omitted support (Part no. One of the bartacks 2- 1 - 1400-6) not catching all four layers of nylon webbing as specified on Drawing 2- 1-1400 Webbing not looped in buckle X X X General Snap f
31、astener Broken, cracked, or malformed; corroded area; burr or sharp edge specified, where required Finish omitted or not as Button or socket component not installed in orientation specified Clinched excessively tight, cutting adjacent materi as Clinched loosely, permitting any component to rotate fr
32、eely but not to the degree that any component can be expected to become detached during use X X X X X 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-44071 4 77777Ob 0447555 5 = MIL-S-44091 - Clas sif ication Defect Major Minor Examine Hardwa
33、re: (contd) Snap fastener Clinched loosely to the degree that components can be expected to become detached during use More than two splits in button or eyelet barrel Fastener not functioning properly, i.e., fails to be snapped closed, provide a secure closure or to open freely (coat d) Eyelets End
34、clips Seam and stitchings: Open seams NOTE: The fastener shall be snapped and unsnapped twice to determine whether parts of fastener separate freely and also effect a secure closure . Clinched loosely, permitting either component to rotate freely Clinched excessively tight, cutting adjacent: materia
35、l Washer omitted More than two splits in eyelet or washer barrel Insecurely clinched or clinched excessively tight, cutting webbing Up to and including 1/2 inch More than 1/2 inch NOTE: A seam shall be classified as an open seam when one or more stitches joining a seam are broken, or when two or mor
36、e consecutive skipped or runoff stitches occur. 6 X X X X X X X X X X Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-h MIL-S-LI407L BLI m 777770b 0447556 7 m MIL-S-44091 Classification Examine Defect Major Minor Seams and stitchings: (contd) Stitch
37、type Stitch tension Stitches per inch Stitching ends Thread breaks, skipped stitches or runoffs Rows of stitching Compone nt and as sembly Incorrect stitch type hose tension, resulting in a loose top or bobbin thread Excessively tight tension, resulting in puckering of material One stitch less than
38、minimum Two or more stitches less than One or more stitches in excess specified minimum specified of maximum specified Not secured as specified Thread breaks, or two or more consecutive skipped or runoff stitches, overstitched less than 1/2 inch in each direction beyond the defective stitching area
39、NOTE: Thread breaks, or two or more consecutive skipped or runoff stitches not overstitched shall be classified as open seams. Any row omitted Any required component or operation omitted (unless otherwise classified herein) Any component misplaced or not assembled as specified (unless otherwise clas
40、sified herein) Needle chews Any unauthorized repair Webbing components not routed through buckles as specified X x. X X X X X X X X 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-44071 4 7777706 0447557 7 W 1 MIL-S-4409 1 *. . ; Classificati
41、on Examine ir Defect Major Minor C le ann es s Dirt or stain clearly noticeable, thread ends not trimmed throughout as specified X 4.4.4 End item dimensional examination. The end item shall be examined for conformance to all dimensions including stitch margins, shown on Drawing 2-1-1400. Any dimensi
42、on not within the specified tolerance shall be classified ae a defect. The lot shall be expressed in units of one chin strap. The sample unit shall be one complete chin strap. The inspection level shall be S-3 and the AQL, expressed in terms of defects per hundred units, shall be 4.0. 4.4.5 Packagin
43、g inspection. An examination shall be made to determine that the preservation, packing, and marking comply with the section 5 requirements. shall be scored in accordance with the list below. shippingcontainer fully packaged with the exception that it need not be closed. Examination of closure defect
44、s listed below shall be made on shipping container6 fully packaged. item lot. defects per hundred units, shall be 2.5. Defects The sample unit shall be one. The lot size shall be the number of shipping containers in the end The inspection level shall be S-2 and the AQL, expressed in term of Examine
45、Defect Marking (exterior .Omitted; incorrect; illegible; of improper size, and interior) location, sequence, or method of application. Mat e ri als Any component missing, damaged, or not as specified. Workmans h ip Content Inadequate application of components, such as incomplete closure of container
46、 flap, improper taping, loose strapping, inadequate stapling. Bulged or distorted container. Number of bundles per shipping container is more Number of chin straps per bundle is more or less or less than specified. than required. - i/ - i/ For this defect, one bundle from each shipping container in
47、the sample shall be. examined. 4.4.6 Examination for palletization. An examination shall be made to determine that the palletization complies with the section 5 requirements. Defects shall be scored in. accordance with the list below. The sample unit shall be one palletized 8 Provided by IHSNot for
48、ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-44071 q W 9777706 OLi475S O W MIL-S-4409 1 unit load fully packaged. The lot size shall be the number of palletized unit loade in the end item inspection lot. expressed in terms of defects per hundred units, shall be 6.
49、5. The inspection level sbll be S-1 and the AQL, Examine Defect Finished dimension Length, width, or height exceeds specified maximum requirement . Pallet izat ion Pallet pattern not as specified. Interlocking of loads not as specified. Load not bonded with required straps as specified. Weight Exceeds maximum load limits. Marking Omitted; incorrect; illegible; of improper size, loc
