Non Deployment Auto Airbags

Each year there are approximate 10 - 21 millions motor vehicle accidents (1980 - 2010) that occur. 

Airbag Components

Most airbag systems are made up of three basic components. They are as follows:

The bag: is constructed of a woven material similar to nylon, which is folded like aparachute. They are coated with talc like powder that lubricates the air bag material for storage. After deployment, this powdery dust may contain residue from the chemical reaction, which may cause minor irritation. 

The inflation system: is similar to a solid rocket booster. This solid material ignites which burns extremely hot and rapidly to create gas. This action inflates the nitrogen gas (pulsed) via the chemical reaction of sodium azide (Na N3) and potassium nitrate (KNO3), in some older vehicles.

Airbag Sensors

Are an electrical and/or mechanical device, which triggers a firing squib, which activates the inflation system and deploys the air bag. The electrical sensor uses a tiny accelerometer, which determines certain types of negative acceleration (decelerations). Generally, airbag systems will be deployed at a vehicle that is traveling a range of 

minimum speeds. Of course, this is subject to many additional factors, such as type of impact, position, delta v (change in speed), and location of the subject vehicle. However, mechanical sensors (switch) close when mass shifts via the vehicle.

Advanced Airbag Systems - Next Generation

In advanced systems vehicle manufacturers (OEM's) are using special sensors to differentiate occupants size and/or weight. This in turn can vary the output of the airbag(s), which in fact makes the system safer. 

Many OEM's use a propriety chemical compound, which they claim to be less toxic, then NaN3 for the inflation system. 

The airbag itself may have multi-stage compartments, which in fact slows the forward velocity (up to 200 mph / totally time is 20-30 milliseconds; first version) of the bag and has a maximum pressure of 5 psi fully inflated. 

Some newer vehicles, are being equipped with side / curtain, knee, belt(s), seat / door mounted airbags as well as the required frontal ones. Most side airbags have separate highly compressed air tanks (approx. 3.5K), which make the system potentially dangerous for first responders, if they do not have the proper information.

Vehicle Modifications - Airbag On-Off Switches 

Automobile airbag switches were designed to accommodate people with disabilities and comply with Federal Motor Vehicle Safety Standards (FMVSS) regulations when specific notifications are made. 

Government Regulations

Notwithstanding, all motor vehicle dealers and/or repair shops must comply with the certain laws and/or regulations (49 CFR Parts 571 and 595) **. Notwithstanding, if the Airbag On-Off Switch is to be installed, they must have the following:

1) Vehicle owner present, authorization letter from NHTSA and liability waver.

2) Install a retrofit on-off switch for each air bag covered by the agency’s authorization

3) Ensure that each cut-off switch meets all of the following performance requirements.

a) Be activated solely by a key.

b) Cause the air bag to remain turned off until manually turned back on using a key and the on-off switch.

c) Be accompanied by a telltale light in the vehicles interior. This telltale light must indicate when an air bag has been turned off and be visible to an occupant of the driver’s seat and all front seat occupants.

d) Not affect the ability of the required airbag readiness indicator to monitor an air bag that is not turned off. The indicator must show whether the air bag is functioning properly.

e) If a single on-off switch is installed to control both the driver’s and passenger’s air bag, the on-off switch must be capable of turning off one air bag without turning off the other. For a single on-off switch controlling both air bags, the telltale light must indicate which air bag is off.

4) Provide the owner with an insert for the vehicle owner’s manual describing the operation of the on-off switch, listing the risk groups on the request form.

a) Stating that the on-off switch should only be used to turn off an air bag for a member of one of those risk groups, and stating the vehicle specific consequences for using it for persons who are not members of any of those risk groups. Those consequences must include the effect of any energy managing features, e.g.…load limiters on seat belt performance.

Conclusion

It bears mentioning that as of June 1, 1998, over 30,000 switches have been authorized by NHTSA. However, only 1,000 dealers/repair shops have returned the required forms **.

A small percentile, of vehicle accidents that resulted in non-deployment of airbag(s) and injuries, were caused by disabling the airbag system.

Our Expert Witness Services

Includes the following states: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey (NJ), New Mexico, New York / NY / New York City / NYC, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania (PA) , Rhodes Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming.

** Source: NHSTA

This article entitled Non-deployment of automobile airbags is for informational purposes