Takata Airbag Recall
Automotive recalls have been all over the news recently one example is GM's nightmare of 2014 in which over 2.6 million GM vehicles were recalled worldwide, and blamed for the deaths of at least 13 people. Another large recall was recently announced that involved faulty airbags manufactured by the Japanese automotive parts company, the Takata Corporation specifically faulty airbags. This article will explore technical aspects of the Takata airbag recall and its impact on the industry.Airbag Design
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| Figure 1. Airbag Diagram Image by Sidney Jablonski via Behance |
The basic concept behind airbag design is simple: a safety device that uses a flexible fabric envelope, that can be rapidly inflated in the event of a collision in order to reduce impact forces. Even though the concept is simple the design and deployment of airbags can be quite complicated.
In a collision vehicle sensors trigger the airbag to deploy when threshold conditions have been reached. In the United States airbags are required to deploy, when a force equivalent to hitting a wall at 14 mph has been detected. Once the deployment has begun an ignitor starts a rapid chemical reaction to produce nitrogen gas to fill the air bag. Note in Figure 1 the the chemical reaction is caused by sodium azide pellets. Sodium azide was a very common propellant in early airbags but is not typically used today due to its toxic nature. Modern airbags utilize less toxic propellants like ammonium nitrate or nitroguanidine. From when the the ignitor is triggered to when the airbag is fully inflated takes around 0.4 seconds.
Thankfully safety restraint technology has advanced greatly from the early 1970s when airbags were first being implemented into passenger vehicles. Due to these advancements and regulatory efforts by the National Highway Traffic Safety Administration, the Department of Transportation estimates that between 1987 and 2012, frontal airbags have saved over 37,000 lives.
Thankfully safety restraint technology has advanced greatly from the early 1970s when airbags were first being implemented into passenger vehicles. Due to these advancements and regulatory efforts by the National Highway Traffic Safety Administration, the Department of Transportation estimates that between 1987 and 2012, frontal airbags have saved over 37,000 lives.
Takata Airbag Failures
From April 2013 to March 2015 17 million vehicles from 10 different automakers with frontal airbags manufactured by Takata have been recalled. The affected vehicles ranged in model years from 2002 to 2008.
The recall has been caused by a faulty propellent that could deteriorate over time, especially in humid climates. In the event of a deployment the faulty propellent could cause excess pressure in the inflater which can lead to several components in the inflated to rupture, potentially becoming lethal shrapnel blasted at high velocities into the driver and/or passengers.
Posted right is a video by CNNmoney via YouTube, which outlines key information on the airbag recalls. According to the video at least 4 people have died from the defective airbags.
Aftermath
After further investigation it has been found that Takata was aware of these potentially lethal flaws before the airbags were tested by federal regulators. This blatant disregard for engineering ethics is a serious issue in today's auto industry. Faulty products such as an ignition switch or airbag inflator could lead to serious injury or even death. In the past engineering disasters like these have been harbingers for change in safety regulations and policy, paving the way for new designs and standards in the engineering community and ultimately creating a better, safer world of engineering feats.
Seeing many recalls throughout the years has really diluted our awareness of the subject at hand. Which is of course that some companies will try to still release a potential hazardous product to the market. This situation also leaves us consumers with a multitude of questions regarding our safety with new products. Questions such as: was not enough testing done on the airbags before they were shipped out, or perhaps they did not do enough research in the propellant that was to be used for the airbags? These are the types of questions that must be answered when looking at this situation.
ReplyDeleteDo you think that more testing needs to be done on safety systems such as the airbags on a passenger vehicle to make sure that they are not going to fail or simply that more research needs to be put into the design beforehand to completely avoid mechanical failures such as the Takata incidents?
Also, do you happen to know what the faulty propellant was, and what caused it to deteriorate? I ask this because like you said earlier in the blog that modern airbags used ammonium nitrate or nitroguanidine to expand. I question why the Takata Corporation would use a different propellant to fill their airbags if the ammonium nitrate or nitroguanidine works so well? Or was it perhaps that they just got their mixture wrong if there was anything that went with the ammonim nitrate or nigroguanidine? Such situations such as the Takata incident always leave more questions than answers.
Thank you for your feedback! I'll try to answer your questions as thoroughly as I can.
ReplyDeleteFirst off I'll concede the fact that I don't have enough knowledge on safety testing, or inflation propellent chemistry to give you a quality answer. I believe engineering disasters like this one are the perfect time to reform the system of communication between engineers and testing officials. For your question on the inflation propellent, I believe Takata made this change for strictly economic benefits. I am sure to fully understand understand how this faulty product slipped through the testing phase would take an in depth analysis on propellent chemistry and testing specification standards.
Hopes this answers a few of your questions. I appreciate your interest.