There are over 230 current model year vehicles in the U.S. market that offer seat mounted side airbag systems. Compared to the considerable amount of crush space present in frontal crashes, the relatively limited amount of crush space available in side crashes creates a challenge for side airbag deployment performance. In the case of seat mounted side airbag technology, when the side impact sensor senses an impact that warrants deployment, it sends a deploy signal to the airbag module located in the outboard seat bolster. The airbag must then deploy from the seat and continue to move into position between the occupant and the interior door surface before the gap closes due to the intruding object. The deployment timing and positioning of the airbag is critical in providing enhanced occupant protection.

In this study, 88 front seat mounted side airbag systems from 1999-2010 model year vehicles were analyzed. The side airbag systems included airbags that deploy through seat bolster seams and systems that deploy through discrete seat deployment doors. Of the 88 production seat side airbag systems tested, 38 were equipped with side airbags that provide only thoracic coverage, 27 provided a combination of head and thoracic coverage, and 23 provided thoracic and pelvic coverage. Seventy-eight of the systems were unique;​ ten of the systems were repeat deployments.

The front seats equipped with side airbag systems were mounted on a generic fixture with the outboard seat bolster packaging the airbag placed approximately 100 mm from a Plexiglas reaction surface. The Plexiglas was backed with a grid of 2 inch squares to utilize in film analysis of the deployment. High speed cameras were placed to capture front, profile, and rear views of the airbag deployment.

The deployment time intervals associated with initial break out (airbag first becomes visible), two inch extension forward, six inch extension forward and full extension position were recorded. The average deployment time calculated for break out, two inch extension, 6 inch extension, and full extension deployment intervals for the total set of seats was calculated as 3.3 ms, 5.0 ms, 7.3 ms, and 14.9 ms, respectively. The standard deviation characterizing the variation within each deployment interval was calculated as 1.17, 1.17, 1.83, and 5.73 ms, respectively. Further comparisons of average time and variation in timing between types of side airbags (thorax, head/thorax, and pelvis/thorax), deployment mechanisms (through seam vs. discrete door), repeat deployments, and across model years were also made. Discussion regarding the factors that influence the variation in deployment timing among the airbag types, deployment mechanisms, and model year groupings is included