The DH-132S and DH132AS Combat Vehicle Crewman (CVC) Protective Helmets were developed by Gentex Corporation as upgrades to the DH-132 and DH-132A models both of which were type classified for U.S. Army personnel.

The DH-132S/DH-132AS retains the compatibility of the DH-132 and DH-132A models with field components such as binoculars, protective masks, and vehicle instruments while offering improvements in the areas of comfort, sound attenuation, and helmet retention and stability.

The DH-132S/DH-132AS helmet assemblies are made up of three main components: protective shell, energy absorbing liner, and communications kit. The liner and communications kit are combined to create a headset which interfaces with a removable shell subassembly.

Bump protection is provided by the combination of the outer shell and the energy absorbing liner which consists of impact absorbing foam in an aramid mesh fabric for retention and fire resistance. Additional proprietary design features of the DH132-S/DH-132AS helmet aimed at improving noise attenuation include an earcup tension spring and a raised inner ring on the earseals which reduces outside ambient noise while improving intelligibility.

HELMET SHELL: The shell comes with a standard olive drab walnut flour finish and black rubber edge beading. Two adjustable hanger tabs at the front of the shell facilitate attachment to the headset and allow for fitting adjustments. A snap on the back of the helmet shell permits the attachment to the adjustable rear attachment tab on the modified CVC liner.

MODIFIED CVC LINER: The modified CVC liner affords optimal fit, comfort, and stability. It consists of energy-absorbing foam pads enclosed in aramid mesh fabric. The energy-absorbing pads feature a more ventilated surface than earlier-style pads, thus making the helmet more comfortable for extended wear. An aramid simplex front brow pad cover enhances comfort at the upper forehead area. The liner offers the following adjustment features:

Adjustable front liner hanger tabs. These prevent shell rotation and a fitting adjustments after the liner has been installed within the helmet shell.

Top Adjustment Strap. This feature allows for adjustment of head width and earcup height and prevents the earcups from moving out of the circumoral region when the chinstrap is secured, a key improvement in maintaining sound attenuation.

Rear Adjustable Tab. This facilitates attachments of the CVC liner to the snap on the rear of the helmet shell and prevents forward rotation of the helmet.

Nape strap with hook-and-pile-closure. This redesigned, one handed strap affords a snug fit in the nape area with increased shear strength due to the loop back design.

CHINSTRAP: Attached to the CVC liner via snap fasteners, is constructed of woven aramid webbing with an adjustment buckle.

SOUND-ATTENUATING EARCUPS: The rotatable earcups are designed for a secure fit and optimum sound attenuation. The earcups can be adjusted vertically via the adjustment straps on the CVC liner. A tension spring adjusts pressure of the earcups to the crewmember�s head. A raised ring on each padded, non-hardening, polyurethane earseal further enhances the fit and sound attenuation with minimal pressure to the head.

COMMUNICATIONS SYSTEM: The DH-132S/DH-132AS is equipped with an MK-1697/G communications kit (or other optional kits) which includes a microphone (dynamic or noise canceling electret), two earphones (one installed in each earcup), a cordset with a lower AP-107XL plug, and a radio-intercom switch.

SUN, WIND, DUST, GOGGLE RETAINER: A retainer strap is attached to the rear of the helmet shell to secure the Sun, Wind, Dust, Goggle strap to the helmet.

ACCESSORIES / OPTIONS:

OPTIONAL ACTIVE HEARING PROTECTION (AHP): An optional Active Hearing Protection (AHP) talk through system is available for use with the DH-132S/DH-132AS. This battery-operated system allows the crewmember to have noise attenuation plus the ability to hear conversations clearly; it also helps protect the crewmember�s hearing by suppressing noise levels above 85 decibels. The AHP system consists of an outside communications module on the left earcup (as worn) and a rotary switch on the right earcup. Alternatively, the AHP feature is available from Gentex in a self sustained plug-in module which is worn on the body with a clothing clip.

ACTIVE NOISE REDUCTION (ANR): ANR is available as an option for increased attenuation at the lower frequencies 31.5 through 1000 hertz.

Conversational Communications Unit: The DH-132S/DH-132AS will accept a modified Conversational Communications Unit (Model 6011) which is designed to provide two-way communications for the user when they are disconnected from the vehicle communications system but while wearing the helmet and a chemical defense mask with integrated microphone.

ELECTRET MICROPHONE: The MK-1697/G headset-microphone can be modified by installing a transformer and diode capacitor network in the left earcup to permit the use of a high performance electret microphone with superior noise canceling characteristics and improved EMI performance.

FACESHIELD KIT: A protective faceshield designed for use with the DH-132S/DH-132AS helmet and provides limited ballistic and impact protection in the eye, face, and jaw regions. The faceshield attaches to the front of the helmet and may be stowed on top of the helmet when not in use.

VISOR HOUSING KIT: The visor housing kit consists of a U.S. Army helicopter pilot type protective visor housing and a single polycarbonate visor. The visor housing attaches to the front of the helmet shell and contains a knob for raising or lowering the visor. A clear, neutral or laser visor lens may be ordered.

MINIMUM PERFORMANCE REQUIREMENTS:

IMPACT RESISTANCE: The DH-132S/DH-132AS ballistic helmet shell assembly limits the acceleration of a test headform to less than 75gs when subjected to two identical impacts from an 18 inch drop using a hemispherical anvil, (ANSI-Z90.1 test method used).

BALLISTIC RESISTANCE: The DH-132S has a non-ballistic fiberglass shell. The DH-132AS helmet shell has an aramid shell with a V50 ballistic rating of not less than 1400 feet per second when tested in accordance with MIL-STD-662. Higher resistance shells are available on special order.

SIZING: The DH-132S and DH-132AS with the improved inner liner and shell adjustment straps reduces the number of sizes required to fit the majority of users. Available in three sizes (small, medium, large, and X-large). The medium and large fits 90 percent of the users with minimal adjustment. The helmet shells are available in 2 sizes. The result is an almost universal size system except for the special case in either end of the population range.