Air bag safety systems are intended to function within the parameters of the vehicle interior produced by the manufacturer. This means air bag deployment speeds, surface area coverage and directional activation zones are designed so that the air bag strikes its intended target—the occupant—and not an aspect of the interior vehicle configuration.
Improper installation of police equipment can seriously disrupt the effectiveness of the air bag and can cause additional safety issues. An air bag deploys in approximately one-twentieth of a second: any piece of equipment in its way can cause major issues. According to federal motor safety laws, the area where an air bag deploys is known as the air bag deployment zone. The best source for identifying this is from the automotive manufacturers and aftermarket companies, and you should consult with them before making any mounting decisions.
According to General Motors (GM) and Ford, the following are guidelines when installing aftermarket police items.
Push Bumpers
According to Ford, different styles of push bumpers might affect the timing of air bag deployment because crash testing hasn’t been performed on every style on the market. Even though Ford says that timing of deployment could be affected, they also state that use of a push bumper that mounts solely to the bumper shouldn’t have a significant effect overall.
GM, on the other hand, says that installing push bumpers will most likely not affect air bag sensors up front—as long as the vehicle structure itself isn’t modified. They aren’t aware of any adverse effects from the many push bumpers that have been installed on current model GM police vehicles with air bags.
Interior Dash Area: Passenger-Side Air Bag Deployment
GM says that aftermarket equipment can be mounted in police cars with passenger-side air bags. However, the item must be mounted outside of the deployment zone because air bags inflate at a high rate of speed and force and will interact with any object in the deployment zone. If it hits a piece of equipment in this zone, it could propel the equipment into a vehicle occupant, causing injury. GM says that factors, including the proximity of the object to the inflatable restraint, the size and shape of the object, how the object is mounted to the vehicle and the type and severity of the crash all affect the possibility of an air bag dislodging it.
Furthermore, it’s not just a loose object that can cause issues—an item mounted in the deployment zone can tear the fabric or affect the shape of the air bag upon deployment, thus reducing the ability of the bag to provide restraint. Because of this, GM can’t recommend the placement of any equipment in the deployment zone, even if it’s shielded to protect it from damage.
Ford says that no aftermarket items can be placed in the path of air bag deployment zones and provides specific drawings that define those zones.
Aftermarket manufacturers like National Products, makers of RAM Mounts, recommend that all items be installed outside of the air bag deployment zone, as well as in accordance with the automotive manufacturer’s requirements and guidelines. RAM states that the use of a multi-adjustable mount must allow the MCT or other item to be repositioned out of the path of the air bag system while the vehicle is in motion. These should only be repositioned when the vehicle is at a complete stop and safely out of traffic.
Front Console Area
GM’s front passenger air bags deploy differently depending upon the type of vehicle and the particular instrument panel design. In some vehicles, such as the Chevrolet Tahoe, the passenger air bag deploys through a door mounted on the vertical rearward surface of the instrument panel, above the glove box door. Other systems, like the one in the Chevrolet Impala, deploy from beneath the instrument panel top pad. The entire instrument panel top pad is the “deployment door,” from under which the inflating air bag emerges.
When an air-bag deployment occurs, the inflating passenger air bag pushes up on the instrument panel top pad, releasing special fasteners across the rearward edge of the top pad. This allows the top pad to rotate upward so that the passenger air bag may emerge. The top pad opens widest at the right-hand side, and is usu ally forced into contact with t he windshield on the right-hand side of the vehicle. Because of this, instrument panel top-mounted special equipment, such as a radar antenna and control unit or video camera, must be positioned to the left of the vehicle center line. This equipment must be mounted as low as possible and securely fastened to the top pad to avoid being dislodged in the event of a crash and possible air bag deployment.
However, according to GM, during the process of securely fastening special equipment to the top pad, the top pad itself can’t be fastened to any other vehicle component, such as the cluster trim plate. Specialty equipment installation must not prevent the top pad from rotating upward during deployment. If you can find a place to mount equipment down low, off the left of centerline or in the center console, do it and stay away from the top pad.
Side Seat & Head Curtain Air Bags
Ford’s side-impact sensors are mounted inside the doors. Because of this, they state that nothing can be added to the doors that might interfere with sensor operation and side air-bag deployment. They also state that nothing should be mounted between the side of the front seat and door trim that could interfere with side air bag deployment, and that the installation of the partition must not interfere with roll curtain air bags and side air bag deployment. They provide clear illustrations of these areas in their installation guide for police Interceptors.
According to GM, head curtain side air bags are designed to deploy downward from the interior roof sides to the bottom of the door windows. Therefore, partitions and barriers can’t be mounted within side air bag deployment zones because this will result in unintended interaction between the barrier and the inflating side air bags. To reduce the risk of injury to the vehicle occupants, GM recommends that the side air bag zones be kept free of any customer-installed equipment.
Summary
Air bag systems are complex and many considerations must be taken into account when installing aftermarket equipment inside a patrol vehicle. Remember: Anything can become a projectile inside a vehicle in a crash. The only way an air bag can help you is if it’s allowed to do its job as designed. This means carefully researching proper locations that place equipment low, secure and clearly out of the way of air bag deployment zones.
Although this article provides some guidelines, it in no way replaces thoroughly researching information provided by the manufacturer of your automobile and the equipment in question to ensure proper and safe installation. For more information, visit the websites found under “References,” below, and always contact the fleet division for full and complete installation guidelines and instructions.
Editor’s note: If you’ve had the unfortunate experience of crashing one of your newer cars, take a close look at the interior of the vehicle. Look for any equipment or installation that broke away or may have caused problems. Use these wrecked cars as learning opportunities for future equipment. Making the same mistakes over and over does nothing to improve safety and actually sets the agency up for increased liability.
References
Ford Police Vehicles: Safety Information—www.fleet.ford.com/downloads/SpecVehPolice/Police%20Interceptor%20Mod%20Guide%20Section%203_DRAFT_10_11.pdf
Gamber-Johnson—www.gamberjohnson.com
GM Police Vehicles: Safety Information—www.gmfleet.com/government/products/police_safety_info.jsp.
Havis—www.havis.com
Jotto Desk—www.jottodesk.gojotto.com
Ram Mounts—www.rammount.com
