GL PD 19-06 w Amendment 1 Advanced Combat Helmet (Legacy).pdf

PURCHASE DESCRIPTION

HELMET, ADVANCED COMBAT (LEGACY ACH)

Record of Revisions

GL-PD 19-06

Amendment 1

01 June 2021

SUPERSEDING

GL-PD 19-06

07 August 2019

REV CHANGED

BY

REVISED

PAGE(S)

DESCRIPTION DATE

(D/M/Y)

Approval

- PM SPE -

Initial release of Legacy ACH with DOT&E protocols incorporated

07/08/19 BRG

- PM SPE 3

Amendment 1 updated title page and added paragraph 1.3.1 on page 3.

06/01/21 BRG

DISTRIBUTION STATEMENT C. Authorized distribution is to U.S. Government Agencies and their Contractors for official use or for administrative and operational use as determined on 1 August 2019. Other requests for this document shall be referred to Product Manager Soldier Protective Equipment, Program Executive Office Soldier, US Army, 10170

Beach Road, Building 328T, Fort Belvoir, Virginia 22060

INCH-POUND

GL-PD 19-06 01 August 2019

MILITARY INTERESTS:

Custodians: Preparing activity:

Army – PM SPE Army – PM SPE

NOTE: The activities listed above were interested in this document as of the date of this document. Since organizations and responsibilities can change, you should verify the currency of the information above using ASSIST online database at https://assist.daps.dla.mil/quicksearch/.

1. SCOPE

1.1 Scope. This document covers the performance and verification requirements for the

Advanced Combat Helmet, a protective helmet consisting of a ballistic protective shell, pad suspension system, and 4-point chinstrap/nape strap retention system. The ACH is a Critical

Safety Item.

1.2 Classification. The helmet assembly will be of the following Types and Classes as specified (see 6.2).

Type I – Advanced Combat Helmet (No Hole for Night Vision Goggle Mount)

Class 1 - 3/4-inch thick pad system, Foliage Green 504

Type II – Advanced Combat Helmet (One Hole for Night Vision Goggle Mount)

Class 1 - 3/4-inch thick pad system, Foliage Green 504

AMSC N/A FSC 8470

Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be used in improving this document should be addressed to: Product Manager – Soldier

Protective Equipment, Program Executive Office – Soldier, US Army, 10170 Beach Road, Building 328T, Fort Belvoir, Virginia 22060.

https://assist.daps.dla.mil/quicksearch/

1.3 Schedule of sizes. The helmet assembly is constructed in the following sizes (see 6.2).

SCHEDULE OF SIZES

Small (S)

Medium (M)

Large (L)

Extra-Large (XL)

Extra Extra-Large (XXL)

1.3.1 National Stock Numbers: The helmets label shall include National Stock Numbers

(NSN) as defined below:

Small – 8470-01-694-8656

Medium – 8470-01-694-8660

Large – 8470-01-694-8663

Extra Large – 8470-01-694-8664

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in sections 3, 4 and 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 that they must meet all specified requirements documents cited in sections 3, 4 and 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 to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the solicitation or contract.

DEPARTMENT OF DEFENSE SPECIFICATIONS

MIL-DTL-32075 - Label: For Clothing, Equipage and Tentage (General Use)

MIL-DTL-46593B

W / Amendment 1 - Projectile, Calibers .22, .30, .50, and 20mm Fragment-Simulating

MIL-DTL-64159 - Coating, Water Dispersible Aliphatic Polyurethane, Chemical Agent

Resistant

MIL-DTL-83133 - Turbine Fuels, Aviation, Kerosene Types JP-8 (NATO F-34), NATO

F-35, and JP-8 + 100(NATO F-37)

MIL-STD-3004D - Quality Assurance/Surveillance for Fuels, Lubricants, and Related

Products

MIL-PRF-372 - Cleaning Compound, Solvent (For bore of small arms and automatic aircraft weapons)

MIL-PRF-2104 - Lubricating Oil, Internal Combustion Engine, Combat/Tactical

Service

MIL-PRF-6083 - Hydraulic Fluid, Petroleum Base, for Preservation and Operation

MIL-PRF-46170 - Hydraulic Fluid, Rust Inhibited, Fire Resistant, Synthetic

Hydrocarbon Base, NATO Code No. H-544

DEPARTMENT OF DEFENSE STANDARDS

MIL-STD-662 - V50 Ballistic Test for Armor

MIL-STD-810 - Environmental Engineering Considerations and Laboratory Tests

MIL-STD-1916 - Department of Defense Test Method Standard, DoD Preferred

Method for Acceptance of Product

(Copies of documents are available online at http://assist.daps.dla.mil or from the

Standardization Documents Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA

19111-5094.)

2.2.2 Other Government documents, drawings, and publications. The following other

Government documents, drawings, and publications form a part of this document to the extent specified herein. Unless otherwise specified, the issues are those cited in the solicitation or contract.

DRAWINGS

U.S. ARMY RESEARCH, DEVELOPMENT AND ENGINEERING COMMAND, NATICK

SOLDIER CENTER

2-1 2-1-2515 - Helmet Shell, Advanced Combat, Small

2-1-2516 - Helmet Shell, Advanced Combat, Medium

2-1-2517 - Helmet Shell, Advanced Combat, Large

2-1-2518 - Helmet Shell, Advanced Combat, Extra Large

2-1-2576 - Helmet Shell, Advanced Combat, Extra, Extra Large

2-1-2566 - Helmet Pads

SPE-HPT-19150-6300-003 - RH Improved Retention System (S-XL), Advanced Combat Helmet

SPE-HPT-19150-6300-001 - LH Improved Retention System (S-XL), Advanced Combat Helmet

(Copies of drawings, publications, and other Government documents required by contractors in connection with specific acquisition functions should be obtained from the contracting activity.)

PURCHASE DESCRIPTIONS

AR/PD 12-01 - Improved Retention System

FQ/PD-06-35 - Fragmentation Helmet, Lightweight, USMC

(Copies of this document are available from; Defense Supply Center Philadelphia, ATTN:

DSCP-FQSE, 700 Robbins Ave, Philadelphia, PA 19111, or by contacting the Contracting

Officer.)

http://assist.daps.dla.mil/

DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE SAFETY

DOT FMVSS 218 - Department of Transportation Federal Motor Vehicle Safety

Standard No.218 Motorcycle Helmets

(Copies of documents are available on line at http://www.nhtsa.dot.gov/cars/rules/standards. The complete text of all Federal Motor Vehicle Safety Standards and other NHTSA regulations can be found in Title 49 of the Code of Federal Regulations (CFR). Title 49 of the CFR is published in seven volumes; the fifth volume (Parts 400-999) is where these regulations can be found.

Copies of this volume can be obtained for a cost from the U. S. Government Printing Office, Superintendent of Documents, Mail Stop: SSOP, Washington, DC 20402-9328.

NATIONAL INSTITUTE OF JUSTICE (NIJ)

NIJ Standard 0106.01 - Ballistic Helmets

(Copies of documents are available online at http://www.ojp.usdoj.gov/nij/pubs-sum/223054.htm or from the National Institute of Justice, 810 Seventh St. NW, Washington, DC 20531

U.S. ARMY DEVELOPMENTAL TEST COMMAND, ABERDEEN PROVING GROUND,

MD

ITOP 04-2-805 - FR/GE/UK/US Projectile Velocity and Time-Of-Flight Measurement

(Copies of documents are available by sending to Commander, US Army Test and Evaluation

Command, ATTN: AMSTE-TM-T, Aberdeen Proving Ground, MD 21105-5055)

2.3 Non-Government standards and other publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents are those cited in the solicitation or contract.

AMERICAN ASSOCIATION OF TEXTILE CHEMISTS AND COLORISTS (AATCC)

AATCC Test Method 8 - Colorfastness to Crocking: Crock meter Method

AATCC Test Method 15 - Colorfastness to Perspiration

AATCC Test Method 61 - Colorfastness to Laundering: Accelerated

AATCC Test Method 107 - Colorfastness to Water

AATCC Test Method 143 - Appearance of Apparel and Other Textile End Products after Repeated Home Laundering

AATCC Test Method 169 - Weather Resistance of Textiles: Xenon Lamp Exposure

AATCC Test Method 195 - Liquid Moisture Management Properties of

Textile Fabrics

AATCC Evaluation

Procedure 9 - Visual Assessment of Color Difference of Textiles http://www.nhtsa.dot.gov/cars/rules/standards http://www.ojp.usdoj.gov/nij/pubs-sum/223054.htm

(Copies of documents are available on line at www.aatcc.org or from the American Association of Textile Chemists and Colorists, P.O. Box 12215, Research Triangle Park, NC 27709-2215.)

AMERICAN NATIONAL STANDARDS INSTITUTE

ANSI/ASQ Z1.4 - Sampling Procedures and Tables for Inspection by Attributes

(Copies of documents are available online at www.ansi.org or from the American National

Standards Institute, 1819 L Street, 6th floor, Washington, DC or at http://www.asq.org or from the American Society for Quality, 600 North Plankinton Avenue, Milwaukee, WI 53203.)

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

ASTM D76 - Standard Specification for Tensile Testing Machines for Textiles

ASTM D910 - Standard Specification for Aviation Gasoline’s

ASTM D975 - Standard Specification for Diesel Fuel Oils

ASTM F1358 - Standard Test method for effects of Flame Impingement on

Materials Used in Protective Clothing Not Designated Primarily for Flame Resistance

(Copies of documents are available on line at www.astm.org or from the ASTM

INTERNATIONAL, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19426-

2959.)

(Non-Government standards and other publications are normally available from the organizations that prepare or distribute the documents. These documents also may be available in or through libraries or other informational services.)

2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the event of 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 First article. When specified (see 6.2), sample(s) shall be subjected to First Article

Testing (FAT) (see 4.3 and 6.2). All requirements are listed singularly (i.e., by themselves). In some cases, verification is performed on a test item that has been previously subjected to another verification test. Sequencing of specific verifications is listed in Section 4, if applicable.

3.1.1 Lot Acceptance. Samples, in lots of a single size, shall be subjected to Lot Acceptance

Testing (LAT). Samples will be examined for the defects specified in 4.9.1 and subjected to the tests indicated in 4.8, Table V. Acceptance criteria shall be specified in the contract (see 6.4).

Unless noted otherwise, all LAT will be conducted under ambient conditions.

http://www.aatcc.org/ http://www.ansi.org/ http://www.asq.org/ http://www.astm.org/

3.2 Material and components. All materials and components shall be as specified herein or on the applicable drawings as well as the contactors own documentation and drawings.

3.3 Finished helmet, finished shell and unfinished shell. The following definitions shall apply in this document.

a. A finished shell shall include the shell, any primer, coating, and texturing aggregate, all necessary attachment holes, and any edging and adhesive to hold the edging on.

b. A finished helmet includes the finished shell plus hook disks, a complete pad set, and a complete retention system including any attaching hardware assembled in the standard configuration. The standard configuration is the configuration shown in TM 10-8470-

204-10, WP 0005 (7 pad configuration with oblong/oval pads in the vertical pad configuration).

c. An unfinished shell shall include the raw shell only, drilled with attachment holes (no primer, paint [coating], texturing aggregate, edging, edging adhesive, or hook disks). The unfinished shell must include raised or depressed benchmarks. Since the primary need for benchmarks is testing, benchmarks on the unfinished shell need not be present in the finished helmets for production.

3.4 Design/construction. The helmet shall meet the design requirements of this specification and referenced drawings and parts lists.

3.5 Shell design/shape. The shape of the shell, prior to the application of any edging or finish, shall be as specified herein and shall have the same shape as shown on drawings

2-1-2515, 2-1-2516, 2-1-2517, 2-1-2518, and 2-1-2576 and all subsidiary drawings and parts lists. These Government drawings are for guidance and reference only. Offeror submitted and approved drawings will become contract reference, thus standard, and cannot be deviated from.

The measurements shall be taken to the inside surface only. The outside surface is defined by the inside surface plus the thickness (see 3.5.2). Testing shall be conducted in accordance with

4.9.2.

3.5.1 Shell construction. Upon removal from the mold, the outer and inner surfaces of the shell, excluding the bottom edge, shall be finished smooth and even. If fabric construction is used, there shall be no exposed ends of the fabric fiber showing. Both the inside and outside surfaces of the shell shall be free from any hole, void, delamination, blister, cracking, crazing, dry spot, area of non-resin flow and any pit greater than 1/8-inch diameter or the depth of one ply of the ballistic material, whichever is less, in order to provide a smooth continuous surface.

There shall be no raised fibers, raised pleats, raised wrinkles or raised creases longer than 1 inch on the interior or exterior surfaces. Processing procedures and methods capable of providing uniform properties shall be used. Patching or repair of any ballistic material shall not be performed after the material has been molded.

Remolding shells is not permitted. Plans to correct cosmetic imperfections, which fall within the acceptable criteria detailed above, must be submitted for government written approval prior to implementation; plans submitted for approval must include a detailed description of all tools, materials and methods necessary and cannot be deviated from without additional written approval. Such plans that achieve written Government approval shall become part of the documented production process. Cosmetic improvements shall not degrade ballistic material properties. More than one material (hybrid construction) may be used to achieve best combination performance requirements listed in the document. Testing shall be conducted in accordance with 4.9.1.

3.5.2 Shell thickness and uniformity. The following dimensional criteria are based on an unfinished shell. The maximum thickness for the helmet shells shall not exceed 0.400-inches regardless of the nominal thickness of the helmet. Thickness variations in the helmet shall be gradual. The shell thickness shall not vary by more than 0.100-inches over the entire surface of the helmet. Testing shall be conducted in accordance with 4.9.3.

3.5.3 Benchmarks. The helmet shell shall have raised benchmarks molded into the shell as shown on drawings 2-1-2515, 2-1-2516, 2-1-2517, 2-1-2518, and 2-1-2576 on the interior or exterior. If an integrally molded edging is used (as defined in 3.5.5), periphery benchmarks may be located on the integrally molded edging and shall be at least 0.2 inches (+0.05 -0.00 inches) long. However, the crown benchmark must only reside on the interior of the shell. For the benchmarks located at the periphery of the shell, their length shall extend up past the helmet shell edging (if used, see 3.5.5) a distance of 0.500 (+ 0.250 / - 0.375) - inch beyond the top edge of the edging. If no edging is used, the benchmarks shall be 0.500 (± 0.250) - inch long extending upward from the shell edge. The benchmark at the crown shall be an “x” with each leg measured from the intersection of the “x” 0.250 (± 0.125) - inch long with one leg of the “x” pointing toward the front of the helmet, one to the rear, and one each to the left and right sides of the helmet. The benchmarks shall be clearly visible on a coated shell. Testing shall be conducted in accordance with 4.9.4.

3.5.4 Attachment holes. Holes to attach components to the helmet shell shall be made before application of the coating (see 3.5.6). There shall be no delamination greater than 0.125-inch from the edge of the hole or other damage of the shell material as a result of making the hole.

There shall be minimal fraying, (i.e. uncut material attached at the edge of the hole) as a result of making the hole. At a maximum, the length of the uncut material shall be 0.125 inch.

Additionally, the hardware that passes thru the hole shall pass thru the hole freely and not be impeded or obstructed by any frayed material. Testing for 3.5.4.1, 3.5.4.2 and 3.5.4.3 shall be conducted in accordance with 4.9.1, 4.9.1.1 and 4.9.2.

3.5.4.1 Retention system holes. Holes for the Retention System, after application of the coating, shall be of the diameter as shown on drawings 2-1-2515, 2-1-2516, 2-1-2517, 2-1-2518, and 2-1-

2576. The Retention System Hardware must pass through the holes freely without obstruction, by hand. Testing shall be in accordance with 4.9.1, 4.9.1.1 and 4.9.2.

3.5.4.2 Night vision goggle (NVG) hole(s). The hole placement for the Type II (one hole) ACH shall be the responsibility of the contractor. The contractor will develop a template for the hole placement for Type II using Night Vision Goggle Bracket Kits cited in 3.13. The diameter for

Type II holes shall be 0.200 (± 0.010) inches. Testing shall be in accordance with 4.9.1, 4.9.1.1 and 4.9.2.

3.5.4.3 Eyewear retention strap holes. The eyewear retention strap will be attached using the holes cited in 3.5.4.1.

3.5.5 Edging. The shell shall have a firmly bonded or an integrally molded edging that protects the periphery of the shell from delamination, wear, cuts, and tear. If the edging is integrally molded, it must be repairable or replaceable. The edging itself shall not be susceptible to cutting, wear, or tear. The edging shall completely cover the bottom edge of the shell and extend up the sides a minimum of 0.30-inch of the helmet shell. If the edging is a non-integral component of the molded shell, then the edging shall consist of a one-piece molded construction or one piece cut to length. If the edging is cut to length, the cut end shall be placed at the rear center of the shell and the butt ends shall not overlap and any gap between the ends shall not exceed 0.060-inches. The edging shall be firmly and completely attached to the shell, i.e. there shall be no unbounded areas. The edging shall be rounded at the corners with a minimum radius of 1/16-inch. A corner shall be defined as the transition between the edge of the shell and the inside of the shell and the edge of the shell and the exterior of the shell, i.e. the “lower” part of the edging.

The standoff of the applied edging from the shell (the sides as opposed to the edge or rim) shall be a maximum of 0.070-inch, for both inside and outside surfaces. The edging shall be colored the same color as the exterior of the shell (see 3.5.6). Testing shall be conducted in accordance with 4.9.1 and 4.9.5.1.

3.5.5.1 Edging adhesion. The edging shall remain firmly attached to the shell when tested as specified in 4.9.5.2.

3.5.5.2 Edging Adhesion of edging after heat aging. The edging shall not peel back more than

0.25-inch when tested as specified in 4.9.5.3. For structural and/or integrally molded edging, the edging shall not move more than 0.125 inch when tested as specified in Paragraph 4.9.5.3 for structural edging.

3.5.6 Coating. Following the surface preparation specified in 3.5.6.1 and after application of suitable primer, if used, a minimum of two coats of coating shall be applied to the exterior of the helmet shell including the outside of the edging. The coating for Foliage Green 504 helmets shall conform to MIL-DTL-64159 (either Type is permissible), color Foliage Green 504. The coating shall completely and uniformly cover the shell surface and the outside of the edging.

After drying, no cracks, scuffed areas, blemishes such as peeling, blistering or flaking, foreign matter appearing on or embedded in the finish shall be visible in the coating. While coating is not required for the interior helmet shell, if applied, it shall be a subdued color. The coating shall be applied in accordance with the manufacturer’s instructions.

The final coat made to the exterior shall contain the texturing aggregate specified in 3.5.6.2 and shall be applied uniformly on the exterior surface of the helmet shell including the outside of the edging, but not the bottom edge of the edging. The bottom and inside edges of the edging need not be coated. Hardware exposed on the exterior and interior of the shell, (e.g. screw heads) shall not be coated. Testing shall be conducted in accordance with 4.9.1.

3.5.6.1 Shell surface preparation. Prior to the application of any coating to the surface of the helmet shell, the shell shall be appropriately prepared in order to meet the requirements for finish provided by the coating manufacturer. Permissible surface gaps and pits on the outside surface

(and inside surface if painted) of the helmet shell (see 3.5.1) may be filled with suitable materials

(such as Acryl-Green Spot Putty) to provide a smooth and continuous surface. The rework of defects affecting ballistic material, such as filling blisters of any size, is not permitted. If surface preparation includes abrading, then the ballistic material shall show no signs of being visibly cut, gouged, or raised. Before application of the final coating the surface shall be free of any contaminants including dust, oil, grease or any other foreign matter. Testing shall be conducted in accordance with 4.9.1.

3.5.6.2 Texturing of coating. Texturing aggregate incorporated in the final coat for the exterior of the helmet shall be silica sand or walnut shell flour in accordance with 3.5.6.2.1 or 3.5.6.2.2.

The aggregate shall be uniformly applied to cover the entire exterior of the shell including the outside of the edging. Testing shall be conducted in accordance with 4.9.1.

3.5.6.2.1 Sand texturing. The aggregate for sand texturing shall be banded silica sand that is water washed and kiln dried, free of salts and deleterious matter, and containing not more than

1.5 percent of dirt or foreign matter. The sand aggregate shall be that known commercially as

No. 70 and shall have a screen analysis with a Percent cumulative of 34.0 (± 5). The coating-sand mixture shall contain six (6) pounds of sand to one (1) base gallon of coating and shall be reduced to spraying consistency. Testing shall be conducted in accordance with 4.9.1.

3.5.6.2.2 Walnut shell flour texturing. The aggregate for walnut shell flour texturing shall be

40/100-mesh walnut shell flour. The coating-walnut shell flour mixture shall contain no less than 10-ounces and no more than 12-ounces of walnut shell flour per base gallon of coating.

Testing shall be conducted in accordance with 4.9.1.

3.5.6.3 Adhesion of coating. The coating, when cut into squares, shall not lift when tested in accordance with 4.9.6.

3.6 Retention system. The helmet retention system and hardware shall be in accordance with

Product Manager Soldier Protective Equipment (PM SPE) Purchase Description (PD) AR/PD

12-01.

3.6.1 Retention system attachment points. Four attaching points shall be used for the chinstrap/nape pad, two on the front half of the helmet and two on the rear half, each symmetric about the helmet mid-sagittal centerline. The attaching points shall use the holes referenced in

3.5.4.1. The attaching points shall be in accordance with drawings 2-1-2515, 2-1-2516, 2-1-

2517, 2-1-2518, and 2-1-2576. Testing shall be in accordance with 4.9.7 and 4.9.11.4.

3.7 Pad suspension system. The helmet shall utilize a modular pad suspension system consisting of a series of pads that act as the suspension system between the wearer’s head and the helmet shell. The pads shall possess means of easy attachment, removal, and reattachment to the inside helmet shell. The pad suspension system shall attach, remove, and reattach to the helmet shell via hook tape disks permanently adhered to the inside of the helmet shell. The pads shall remain firmly in place when attached. The ease of attachment of the pads and the ability to attach the pads where the wearer desires (i.e. in a variety of locations) shall permit accommodations among different sized and shaped heads. There are three (3) different pad shapes that form the suspension system, round, trapezoidal, and oblong. A complete pad suspension kit shall consist of seven (7) pads as follows: one (1) round pad (crown), two (2) trapezoidal pads (front and back), and four (4) oblong pads (distributed around the perimeter to achieve comfort and stability).

Samples shall be examined for the defects specified in 4.9.1. Drawing 2-1-2566 shows the shapes and dimensions of the pads. The shape of the pad shall meet the shapes shown in Drawing 2-1-

2566 with a tolerance of (± 1/8 inch). The 3/4-inch thick pad set shall be made up of all 3/4-inch thick pads and shall be within 0.0625 inch of the nominal thickness. Testing shall be conducted in accordance with 4.9.8.1. Mandatory source for this component shall be in accordance with 6.8.

3.7.1 Pad construction. The pad shall have at least three basic layers or be designed in such a way as to function in three ways: an inner layer shall contact the wearer’s head, a padding layer shall provide the standoff, comfort, protection and stability, and an outer material layer which attaches the pad to the hook disk inside helmet shell. The three layers shall be permanently joined around the perimeter to prevent disassembly. Testing shall be conducted in accordance with 4.9.8.2.

3.7.1.1 Inner layer material. The inner material that contacts the wearer’s head shall wick moisture away from the wearer’s head and absorb it. The color of the inner material shall be

Foliage Green 504 for all helmet classes. Testing shall be conducted in accordance with 4.9.8.1, 4.9.8.5, and 4.9.10.1.

3.7.1.2 Padding layer material. The padding material shall provide standoff, comfort, protection and stability. The padding material shall not absorb or hold moisture when tested in accordance with 4.9.8.4. It may itself consist of multiple layers. Thickness of this layer shall provide for the bulk of the overall pad thickness required. Testing shall be accordance with 4.9.8.2.

3.7.1.3 Outer layer material. The outer material shall be made of a loop-type material and allow the pad to be attached to the inside of the helmet shell. The material shall have an average peel strength no less than 2.8 pounds per inch of width when tested in accordance with 4.9.9.4. It is desirable that the outer material interface with the currently fielded hook disk (3M p/n SJ3572).

The color shall be Foliage Green 504 for all helmet classes. The outer material shall interface with hook disk. Testing shall be conducted in accordance with 4.9.8.1, 4.9.8.2, and 4.9.10.1.

3.7.2 Pad compression durability. The pads shall be constructed such that they can withstand multiple compressions without failing. Each pad shape and thickness shall be subjected to repeated 1/4-inch compressions and show no signs of degradation. Degradation includes, but is not limited to, the structure of the pad losing its resiliency, not returning to its original shape, and thickness. There shall be no physical damage to any of the pad components.

Physical damage includes, but it is not limited to, breakage of threads (if used), seams, or closures, damage to any of the components such that they do not return to its original shape and thickness. Testing shall be in accordance with 4.9.8.3.

3.8 Hook disks. Hook disks shall interface with the outer material of the pads and attach the pads to the inner surface of the helmets. The hook disks are attached to the inside of the helmet shell by means of a pressure sensitive adhesive. One side of the disk shall be comprised of a means to attach the pad and the other side shall be coated with a self-stick adhesive (pressure sensitive) (see Figure 2). The exterior color (side facing the pad) of the hook disk shall be Black

357. Testing shall be conducted in accordance with 4.9.9.1 and 4.9.10.1.

3.8.1 Hook disk shape and coverage. Hook disk shape is at the discretion of the contractor.

Shapes with square corners (i.e. rectangular or square) or pointed corners are unacceptable since the square corners have a tendency to peel. Shapes shall have rounded corners. A circular shape, 1-7/8 - inch in diameter is known to be satisfactory. Alternatively, the shape shown in

Figure 2 may be acceptable and provide more coverage. An adequate number of hook disks shall be installed on the interior of the shell to allow movement of the pads into any position and to allow securing of the helmet cover. At a minimum, enough hook disks shall be installed to allow the smallest pad to be placed anywhere inside the shell and have at least half (1/2) of the pad’s surface in contact with hook disk. After installation, no hook disks should have air bubbles, or gaps between the hook disk and the shell. There should be no hook disks installed in the ear dome area of the shell. Additionally, no hook disk shall cover any molded-in markings.

Testing shall be conducted in accordance with 4.9.9.1.

3.8.2 Hook disk durability. At no time shall removal of any helmet pad cause the hook material to become separated from the helmet shell. The adhesive shall firmly attach the disk to the inner surface of the helmets with no lifting of the hook disks on any contours within the helmets. Testing shall be in accordance with 4.9.9.2 and 4.9.9.3.

3.8.3 Hook/loop adhesion. The adhesion between the hook disk and the outer material on the pad shall be a minimum of 2.8 pounds per inch of width. Testing shall be in accordance with

4.9.9.4.

3.9 Ballistic protection. The helmet shell shall provide ballistic protection from fragments as well as 9mm projectiles. Protection shall meet the requirements set forth in this document throughout the entire surface area of the helmet unless specified otherwise in this document.

3.9.1 Fragmentation protection - minimum V50 ballistic protection limits (V50 BL(P)). The helmet shell shall be capable of providing the minimum V50 BL(P)s listed in Table II at 0° (±5°) obliquity against the specified right circular cylinder (RCC) and Fragment Simulating Projectile

(FSP) projectiles when tested in accordance with 4.9.11, 4.9.11.1., and 4.9.11.1.1 under the following conditions:

a. ambient

b. extreme hot (160°F)

c. extreme cold (-60°F)

d. after immersion in seawater, tested at ambient temperature

e. after exposure in weatherometer, tested at ambient temperature

f. after accelerated aging, tested at ambient temperature

TABLE II. Minimum V50 BL (P)s

Projectile Minimum V50 BL(P) at 0° (±5°) Obliquity (ft/sec)

2-grain RCC 1/ 4200

4-grain RCC 3475

16-grain RCC 2475

64-grain RCC 1750

17-grain FSP 2/ 2200

1/ Right Circular Cylinders shall be in accordance with Figure 1.

2/ Fragment Simulating Projectile – MIL-DTL-46593B with Amendment 1, 11

August 2008, with the exception of Hardness Testing per ANSI/ASQ Z1.4, Special

Inspection Level S-3.

V50 ballistic limit testing shall be performed in accordance with 4.9.11.3. Multiple helmet shells may be required to determine the V50 BL (P) for a particular projectile, obliquity, and environmental condition.

3.9.2 Resistance to penetration – 9mm. The helmet shell, including any hardware exposed on the outside of the shell, shall be resistant to penetration from a 9mm Full Metal Jacketed Round

Nose (FMJ RN) bullet with a nominal mass of 124 grains in accordance with NIJ 0106.01 at

1400 (+50, -0) feet per second at 0° (±5°) obliquity when tested in accordance with 4.9.11, 4.9.11.1.2, and 4.9.11.4 under the following environmental conditions:

a. ambient

b. extreme hot (160°F)

c. extreme cold (-60°F)

d. after immersion in seawater, tested at ambient temperature

3.9.2.1 First Article Testing (FAT), RTP requirement.

FAT Part A: There shall be no complete penetrations in the first twenty-two (22) impacts (helmet shell, five (5) helmets required). At least five (5) impacts shall be in each of the four (4) environmental conditions. The 5th helmet will be subjected to the extreme hot condition specified in this document. Should there be ≥ one (1) complete penetration in the first twenty-two (22) impacts then testing will be stopped and the design will have not met the 9mm RTP requirement.

FAT Part B: If there have been no complete penetrations in the first twenty-two (22) impacts as specified in Part A, then testing will continue in accordance with the FAT matrix specified in Annex A. The RTP requirement will then be determined by combining all shots for a particular subtest (i.e., all 9mm RTP/BTD tests will be used in the calculation regardless of shot location), including the first twenty-two (22) impacts.

RTP testing on the helmet shall meet a 90% Probability of no Penetration (P(nP)) with

90% Lower Confidence Level (LCL) for 9mm RTP testing when the LCL is calculated using the Clopper-Pearson method. RTP testing on hardware will be calculated separately but will still maintain the same statistical requirement.

3.9.2.1.1 Helmet Penetration Analysis. Combat helmet designs tested using the 240-shot matrix may not demonstrate uniform probability of no penetration (P(nP)) across all sizes, environmental conditions, and shot locations. If significant differences exist, the data cannot be aggregated and additional testing may be necessary to determine whether the helmet meets the standard for P(nP). See Enclosure 1 in Annex A.

3.9.2.2 Lot Acceptance Testing (LAT), RTP requirement.

LAT Part A: There shall be no complete penetrations in the first five (5) impacts

(helmet shell) for a lot size ≤ 1200 or ten (10) impacts (helmet shell) for a lot size of 1201

– 3200. Should there be ≥ one (1) complete penetration in the first five (5) or ten (10) impacts (based on lot size) then testing will be stopped and the lot will have not met the

9mm RTP requirement.

LAT Part B: If there have been no complete penetrations in the first five (5) or ten (10) impacts as specified in Part A, then testing will continue in accordance with the LAT matrix specified in Annex A. The RTP requirement will then be based on the accept/reject criterion specified in the LAT section of Annex A (RTP on hardware is not subject to this two stage approach and its requirement is based on the specified LAT accept/reject criterion).

3.9.3 Ballistic transient deformation (BTD).

3.9.3.1 Ballistic transient deformation – FAT. For FAT, BTD of the shell imprinted in the clay shall not result in a 90% Upper Tolerance Limit (UTL) with 90% Confidence calculation in excess of 0.63-inch (16.0 mm) against 9mm projectile under the environmental conditions specified in 3.9.2 at 1400 (+50, -0) feet per second at 0° (±5°) obliquity for shots made to the right side, left side, and crown. Shots made to the front and back shall not result in a 90% UTL with 90% Confidence calculation that exceeds 1.0-inch (25.4 mm). For BTD testing, there will be four (4) separate calculations done for the Upper Tolerance Limit (UTL). These four (4) calculations will include all sizes and conditions for each test type (i.e., for calculating the UTL on the crown location, the data will consist of sizes S, M, L, and XL from the Ambient, Hot, Cold, and Seawater subtests). These calculations are as follows:

(1) Calculation for deformations in the Front location only.

(2) Calculation for deformations in the Rear location only.

(3) Calculation for deformations in the Crown location only.

(4) Calculation for deformations in the Right and Left Side locations** only.

**If the BTD measurements from the side locations form two distinct distributions, then separate

BTD UTL calculations will be conducted for each side location.

All four (4) and if necessary five (5) 90% UTL with 90% Confidence calculations must not exceed the 16.0 mm (Crown, Right, and Left side locations) or 25.4 mm (Front and Rear locations) requirement for acceptance. Testing shall be conducted in accordance with 4.9.11, 4.9.11.1.3, and 4.9.11.5.

3.9.3.1.1 Ballistic transient deformation analysis. The purpose of this analysis is to check for significant differences (clusters) between test conditions. Combat helmet designs tested using the 240-shot test matrix might not demonstrate uniform BTD performance across all sizes, environmental conditions, and shot locations. If significant differences exist, the data cannot be aggregated and additional testing might be necessary to determine whether the helmet meets the standard for BTD. See Enclosure 2 in Annex A.

3.9.3.2 Ballistic transient deformation – LAT. For LAT, BTD of the shell imprinted in the clay shall not result in an X% UTL with Y% Confidence calculation in excess of 0.63-inch (16.0 mm) against 9mm projectile under the environmental conditions specified in 3.9.2 at 1400 (+50, -0) feet per second at 0° (±5°) obliquity for shots made to the right side, left side, and crown. Shots made to the front and back shall not result in an X% UTL with Y% Confidence calculation that exceeds 1.0-inch (25.4 mm). For BTD testing, there will be four (4) separate calculations done for the Upper Tolerance Limit (UTL). These calculations are as follows:

(1) Calculation for deformations in the Front location only.

(2) Calculation for deformations in the Rear location only.

(3) Calculation for deformations in the Crown location only.

(4) Calculation for deformations in the Right and Left Side locations** only.

**If the BTD measurements from the side locations form two distinct distributions, then separate

BTD UTL calculations will be conducted for each side location.

All four (4) and if necessary five (5) X% UTL with Y% Confidence calculations must not exceed the 16.0 mm (Crown, Right, and Left side locations) or 25.4 mm (Front and Rear locations) requirement for acceptance. Testing shall be conducted in accordance with 4.9.11, 4.9.11.2, and

4.9.11.5. The BTD requirement will be based on X% UTL with Y% Confidence based on the number of helmets tested. The breakdown is provided below and also specified in the accept/reject criteria found in the LAT section of Annex A.

Helmets Tested UTL (X/Y)

8 75/90 13 80/90

3.10 Weight. The threshold maximum weight of the finished helmet shall not exceed the weights listed in Table III. The finished helmet shall be weighed with the 3/4-inch thick pads and Retention System installed. Finished helmets weighing less than the weights in Table III are desired. Five (5) of each helmet size shall be tested. Testing shall be conducted in accordance with 4.9.12.

TABLE III. Weight

Size Weight (lbs)

Small (S) 2.94

Medium (M) 3.06

Large (L) 3.31

Extra-Large (XL) 3.88

Extra Extra-Large (XXL) 4.00

3.11 Blunt impact protection. The finished helmet shall provide non-ballistic impact protection to the wearer by reducing acceleration of the head during low velocity blunt impact events at various temperatures. As a threshold, for each size shell with 3/4-inch thick pads, and for all tests including the various impact sites and temperatures specified the first impacts shall meet a 90% probability of accelerations not exceeding 150G (gravitational constant) with a 90%

Lower Confidence Level. Second impacts shall meet a 90% probability of accelerations not exceeding 150G with an 80% Lower Confidence Level. Calculations will comprise of all first or all second impacts (as appropriate) including all conditions and shell sizes. The Clopper-Pearson methodology will be used for these calculations. Greater impact protection, i.e. fewer G, is desired as an objective. There shall be no physical damage to the helmet shell that degrades ballistic performance such as delamination, ply separation, or shell fracture. If physical damage such as the above criteria is evident on the inside surface of the helmet, the Government will conduct a 9mm Resistance to Penetration (RTP) test directly in the center of the damage and in accordance with section 4.9.11.4. Additionally, there shall be no indentation on the exterior of the helmet shell in excess of 0.15-inch present after blunt impact testing. If deemed necessary

(excluding the 0.15-inch indentation requirement), the Government will analyze the damage and conduct a non-invasive imaging scan (i.e., CT Scan) of the sample to confirm the damage. Each affected area will be impacted with a 9mm projectile and a Partial or Complete Penetration will be documented as described in sections 6.5.2 and 6.5.3.1. Only the front, crown, right side, left side, and rear locations shall be included in the analysis. The Government reserves the right to impact the nape location after all locations on a helmet have been tested. Additionally, Back

Face Deformation/Ballistic Transient Deformation (BFD/BTD) may be measured for

Government reference. If more than 22 impacts are required, RTP testing on the helmets shall meet a 90% Probability of no Penetration (P(nP)) with 90% Lower Confidence Level (LCL) for

9mm RTP testing when the LCL is calculated using the Clopper-Pearson method. If less than 22 impacts are required, 100% of the impacts must result in partial penetrations to meet the requirement. The helmet will fail the blunt impact test if the data does not meet a 90% P(nP) with 90% LCL or if there is one or more complete penetrations as described previously.

Additionally there should be no damage to any part of the retention system or pad system.

Testing shall be in accordance with 4.9.13.

3.12 Operating Environment. All helmet components shall be constructed such that they can withstand various environmental extremes without degradation.

3.12.1 Sea water resistance. There shall be no structural, visible or operational degradation to the finished shell when subjected to immersion in seawater. The finished shell shall show no evidence of softening, peeling, blistering cracking, delamination, or increase in weight of greater than 3 percent over dry weight or increase in thickness greater than 2.5 percent when tested in accordance with 4.9.3 and 4.9.14.1.

3.12.2 Weatherometer resistance. There shall be no structural, visible or operational degradation to the finished shell when subjected to weatherometer exposure. The finished shell shall exhibit no evidence of cracking, blistering, delamination, and ply separation, separation of edging, increase in thickness greater than 2.5 percent, finish defects or ballistic degradation when tested in accordance with 4.9.3 and 4.9.14.2. Also, the requirements of 3.9.1 (e) shall be met after weatherometer exposure (see 3.9.1).

3.12.3 Field agent resistance. The finished shell, when exposed or subjected to the following agents shall show no evidence of softening, peeling, delamination, ply separation, or tackiness.

As an alternate, the unfinished shell (no coating or edging) may be tested. Testing shall be conducted in accordance with 4.9.14.3.

1. DEET insect repellent, NSN 6840-01-284-3982, O-I-503 Type II, Concentration A

2. Gasoline, ASTM D910

3. Motor Oil, MIL-PRF-2104

4. Hydraulic fluid, petroleum base, MIL-PRF-6083

5. Fire resistant hydraulic fluid, MIL-PRF-46170

6. Fuel Oil, Diesel, ASTM D975

7. Turbine Fuel, Aviation, F-24, MIL-STD-3004, ASTM D1655

8. Rifle Bore Cleaning Compound, NSN 6850-00-224-6656, MIL-PRF-372

9. Lubricating Oil, Weapons (LSA), NSN 9150-00-935-6597

10. Lubricating Oil, Arctic, Weapons, NSN 9150-00-292-9689

11. Face paint, NSN 6850-01-493-7309

3.12.4 Flame resistance. The finished shell shall be self-extinguishing with no after-flame greater than 2.0 seconds (Threshold), 0.5 seconds (Objective). Flaming before the withdrawal of the flame source is permitted according to ASTM D 6413. There shall be no melting or dripping. It is desired, however, that the finished shell be ignition resistant. Testing shall be conducted in accordance with paragraph 4.9.14.4.

3.12.5 High temperature storage and use. All helmet components including the shell, pads, retention system, and hardware shall exhibit no structural, visible or operational degradation or physical damage when subjected to elevated temperature exposure. The shell shall exhibit no cracking, delamination, separation of plies, distortion, softening, change in thickness greater than

2.5 percent, or other deterioration. The paint (coating) shall suffer no degradation or deterioration. The retention system shall be operable (webbing slides, retention system can be cinched down, etc.) and shall have no cracked or damaged components. The pads shall have not have suffered any degradation or damage. Testing shall be in accordance with 4.9.3 and

4.9.14.5.

3.12.6 Cold temperature storage and use. All helmet components including the shell, retention system, and hardware shall exhibit no structural, visible or operational degradation or physical damage when subjected to low temperature exposure. The shell shall exhibit no cracking, delamination, separation of plies, distortion, softening, change in thickness greater than 2.5 percent, or other deterioration. The paint (coating) shall suffer no degradation or deterioration.

The retention system shall be operable (webbing slides, retention system can be cinched down, etc.) and shall have no cracked or damaged components. The pads shall have not have suffered any degradation or damage. Testing shall be in accordance with 4.9.3 and 4.9.14.6

3.12.7 Temperature shock. All helmet components including the shell, retention system, and hardware shall exhibit no structural, visible or operational degradation or physical damage when subjected to temperature shock, hot to cold, and cold to hot. The shell shall exhibit no cracking, delamination, separation of plies, distortion, softening, increase in thickness greater than 2.5 percent, or other deterioration. The paint (coating) shall suffer no degradation or deterioration.

The retention system shall be operable (webbing slides, retention system can be cinched down, etc.) and shall have no cracked or damaged components, or other deterioration. The pads shall have not have suffered any degradation or damage. Testing shall be in accordance with 4.9.3 and 4.9.14.7.

3.12.8 Altitude. All helmet components including the shell, the pads, retention system, and hardware shall exhibit no structural, visible or operational degradation or physical damage when subjected to altitudes from sea level to 15,000-feet equivalent pressure and 40,000-feet equivalent pressure. The test temperature at the 40,000-feet equivalent pressure should be -62oF

(± 5oF)/ -52oC (± 3 oC). The shell shall exhibit no cracking, delamination, separation of plies, distortion, softening, increase in thickness greater than 2.5 percent, or other deterioration. The paint (coating) shall suffer no degradation or deterioration. The retention system shall be operable (webbing slides, retention system can be cinched down, etc.) and shall have no cracked or damaged components, or other deterioration. The pads shall have not have suffered any degradation or damage. Testing shall be in accordance with 4.9.3 and 4.9.14.8.

3.12.9 Vibration. All helmet components including the shell, retention system, and hardware shall exhibit no structural, visible or operational degradation or physical damage when subjected to vibration. There shall be no structural, visible or operational degradation to the finished helmet when subjected to vibration. Minor coating and edging scuffing, marring or wear marks are acceptable. No helmet parts shall become loose or disassembled when subject to vibration.

“Loose” shall be defined as not meeting the original adhesion, tightness, or torque (as applicable) as when manufactured or assembled. Testing shall be in accordance with 4.9.14.9

3.12.10 Impact resistance. The finished helmet shall resist physical damage from impacts. The shell material (not including the finish) shall show minimal signs of structural damage such as delamination, ply separation, or shell fracture or indentation, when subjected to a 40 foot-pound

(ft-lb) impact. Any resulting indentation in the shell shall be less than 0.150-inch in depth. No damage is desired. The exterior finish shall exhibit no flaking, peeling, loss of adhesion, or other failure of the finish except within a 2.0-inch radius around the center point of impact. Testing shall be conducted in accordance with 4.9.14.10.

3.12.11 Compression resistance (top to bottom). The unfinished shell (no coating or edging) shall be resistant to repeated compressions in the top to bottom direction. As an option, a finished shell may be used. If a finished shell is used, then the top of the shell may be lightly sanded to remove aggregate so to obtain a good measurement. There shall be no dimensional change in excess of 0.020-inch immediately (within 5-minutes) following compressions and

0.020-inch after 24 (± 1) - hours when compared to the pretest dimension. Additionally, the shell shall exhibit no visible delamination, ply separation, distortion after the compressions.

Testing shall be conducted in accordance with 4.9.14.11.

3.12.12 Compression resistance (side to side). The unfinished shell (no coating or edging) shall be resistant to repeated compressions in the side to side direction. As an option, a finished shell may be used. If a finished shell is used, then the sides of the shell may be lightly sanded to remove aggregate so to obtain a good measurement. There shall be no dimensional change in excess of 0.200-inch immediately (within 5-minutes) following compressions and 0.125-inch after 24 (± 1) - hours when compared to the pretest dimension. Additionally, the shell shall exhibit no visible delamination, ply separation, distortion after the compressions. Testing shall be conducted in accordance with 4.9.14.12.

3.12.13 Accelerated Aging/Shelf Life. The finished shell shall suffer no structural, visible or operational degradation to the finished shell when subjected to accelerated aging/shelf life exposure according to ASTM D1149 paragraph 5 test apparatus.