Airbags

Airbags (or air bags) are safety devices intended to help protect people in automobiles during crashes. When sensors on a vehicle detect a serious impact, they trigger one or more airbags inside the car to fill with gas at an extremely high speed. The deployed airbags serve as protective cushioning that can help keep people from striking the interior of the vehicle. Airbags underwent a long process of design and development starting in 1952 with the basic idea proposed by an engineer named John W. Hetrick. In the coming decades, major automobile manufacturers and other organizations slowly improved and perfected the invention. In the 1990s, the United States government required airbags in all new cars.

Background

By the first decades of the 1900s, automobiles were becoming common in many areas. By the 1950s, they were a fixture of most cities and towns across the world. Every year, as automobiles became more prevalent, they also became faster and more powerful. Their safety features, however, saw little improvement. These factors combined to contribute to a consistent rise in automobile accidents and injuries and fatalities among automobile users.

In 1952, a Navy engineer named John W. Hetrick was driving with his family when he swerved to avoid a fallen rock and his car crashed into a ditch. He noted that, as the passengers prepared for impact, he and his wife both instinctively lifted their hands to block their daughter from jerking forward and hitting the dashboard. Fortunately, no one was injured in the accident.

Hetrick began pondering the crash and the parents' attempt to protect their daughter. He speculated that he could design a mechanical device that could perform the same task: preventing people in an automobile from hitting the inside of the vehicle during an accident. He began sketching different designs for such an invention.

Hetrick remembered that, while in the Navy, he once repaired a torpedo. The torpedo released a powerful blast of compressed air that blew its canvas covering to the ceiling. Hetrick felt an action such as compressed gas blasting into a fabric bag could provide the perfect means of automobile safety. He patented such a device in 1952.

Although Hetrick's invention demonstrated the basics of the modern airbag, it was not ultimately successful. Experts determined that, as designed, it would not have worked efficiently. His ideas, though, inspired many other engineers and automobile manufacturers to look into similar innovations for road safety.

Early tests proved discouraging, however. The technology of the 1950s was not sufficient to handle the complex tasks involved. A successful airbag would have to accurately detect a potentially dangerous collision and activate an airbag that would be fully inflated within forty milliseconds, an extremely short time. Many more years of experimentation would be necessary before airbags were finally perfected.

Overview

Several major automobile manufacturers and automobile research facilities took interest in Hetrick's design. From the late 1950s to the 1970s, they experimented with new designs and technologies, some borrowed from the electronics industry and the military. However, despite their efforts, no completed airbag design passed the testing phase. Testing suggested that early airbags were too unreliable and some posed a serious danger to small children. By 1973, design improvements made airbags better, and in the mid-1980s, major manufacturers including Mercedes-Benz, GM, and Ford began offering airbags as optional features in new vehicles.

The biggest event in establishing the airbag in industry and society, however, began in 1990, when the United States government became involved in promoting automobile safety. Legislation required all new cars sold in the country to include an airbag or automatic seat belts. The following year, the Intermodal Surface Transportation Efficiency Act (ISTEA) required that, by 1998, passenger and driver airbags become a standard in all new automobiles.

All airbags are mainly intended to reduce the danger of a person's head or upper body hitting the interior of a vehicle during a crash or some other emergency event. Modern vehicles may have two main kinds of airbags, front and side airbags. Front airbags are standard on all new cars since 1998 and all new vans, pickup trucks, and sport utility vehicles since 1999. These airbags deploy directly in front of people in a car to help protect them in head-to-head collisions. Side airbags may be standard or optional features. These airbags deploy from doors and offer protection in the event of side collisions.

Modern airbags use impact sensors in the front of vehicles that measure sudden deceleration (as in the event of a serious crash) and trigger a signal to the airbag unit. A small but powerful explosive charge inside the airbag creates a burst of nitrogen gas that shoots into an empty nylon bag. The bag inflates in less than 1/20 of a second into a protective cushion to absorb impact. Airbags only deploy in certain kinds of crashes—generally high-speed crashes in which seat belts alone would probably not be sufficient.

Although airbags are important and useful protective devices, they are also powerful machines that can, if used improperly, cause harm to people. Automobile users should observe special behaviors to avoid the possibility of being injured by a deploying airbag. For example, front-seat users should not sit or lean too close to the dashboard, as they might be violently thrown back by an airbag. Safety rules are particularly important for young children in cars. Experts recommend that children under 13 should sit in the back seat and that car seats should be installed in a way that will avoid airbag dangers.

Since their widespread adoption, airbags have made a significant impact on road safety. The National Highway Traffic Safety Administration determined that frontal airbags alone likely saved 44,869 lives from 1987 to 2015. Experts and officials stress, however, that airbags are a secondary means of defense for road safety; seat belts are the primary means. Some inventors are experimenting with ways to increase airbag usefulness, such as by using external airbags to help protect pedestrians.

Experts, manufacturers, and legislators recognize airbags as a crucial element of road safety. To ensure that airbags meet their full potential, automobile owners and users should observe certain rules. They must replace used airbags immediately at authorized repair stations, as airbags can be safely used only once. They must also be aware of the risk of defective airbags, which may be subject to recalls, as well as counterfeit or low-quality airbags that do not meet regulations.

Bibliography

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