The mystery of what caused some Takata air bags to spray metal shrapnel after being triggered, killing drivers, remains unsolved after months of testing with an independent panel of engineers.
“This may not be something as simple as just one root cause,” said former National Highway Traffic Safety Administration Administrator David Kelly, who has been hired by the industry to investigate the problem.
It’s a painful, open question for families of victims and a big concern for anyone driving a car or shopping for a new or used vehicle.
Ten automakers, including the Detroit Three, are involved in a massive recall of 17 million vehicles with Takata air bags. Six deaths and more than 100 injuries have been tied to the specific air bag defect.
It’s also unclear whether the replacement air bag systems are safer. That’s because they use the same volatile chemical to inflate the bags, ammonium nitrate, that some suspect is at the heart of the problem. Other air bag manufacturers use less-volatile chemicals, but they cost more.
Chemicals are key to how an air bag operates. When the car’s sensors detect an imminent crash, the inflator — like a rocket booster — sets off a chemical charge to produce nitrogen gas that fills the air bag like a pillow. After the crash, vents in the pillow allow for a slow deflation.