R. Scott King, BSME, Automotive / Mechanical Engineer ::::
Case Synopsis: A passenger in a late model Toyota vehicle was seriously injured when the operator lost control of the vehicle and struck a concrete barrier. After the incident, investigators observed that, while the driver’s front airbag deployed, the right front passenger’s airbag did not. Neither operator nor injured passenger had any recollection of the incident. The only available information regarding the occupants was contained in the police report indicating the passenger was seated in the right front seat. Based on the difference in airbag deployment, as well as the information in the police report, counsel representing the injured passenger initiated a forensic evaluation of the occupant restraint system.
Engineering Analysis: The airbag system in the incident Toyota was capable of independently deploying the right front airbags depending on whether the right seat was occupied. It was also equipped with an Event Data Recorder (EDR) capable of recording pre-crash vehicle speed, braking, airbag system performance during the crash, and pre-existing fault codes. Imaging the data revealed that an intermittent fault within the right front seat occupant detection system had persisted for many hundreds of ignition key cycles before the incident. Additional research revealed this fault had the potential to falsely detect a right front seat passenger thereby affecting right side airbag deployment decisions.
While the fault-code information seemed to provide an explanation of why the passenger airbag did not deploy, additional vehicle evaluation failed to reveal physical evidence indicating the right front seat was occupied. This led investigators to question the seating position of the injured occupant. Doing so revealed physical evidence and witness statements indicating that the injured occupant was actually asleep in the rear seat causing police to amend their earlier report. Accordingly, the difference in airbag deployment was moot despite the existence of a pre-existing fault.
Conclusion: Airbag cases are complex and can be expensive and time consuming to investigate and litigate. Early and thorough investigation can help to evaluate the merits of a potential case, as illustrated in the above case example.
R. Scott King, BSME, Automotive / Mechanical Engineer with DJS Associates can be reached at experts@forensicDJS.com.Case Studies