RUPTURING DRIVER'S AIR BAG INFLATORS

This RQ investigation was opened to collect and analyze additional information to better evaluate the scope and timeliness of Honda's two safety recalls addressing rupturing of the driver's side air bag inflators (08V-593 and 09V-259). In an earlier response to RMD's request for information, Honda indicated that the second recall (09V-259), essentially an expansion of the first (08V-593), was necessary since later information informed that the source of the defect was different than originally postulated, and so the scope of the vehicles affected changed. Honda indicated that it had relied on its supplier of the air bag inflators, Takata, Inc. (Takata), in studying the possible sources of the inflator ruptures and identifying the recall populations. Accordingly, RMD issued a request for information to Takata on November 20, 2009, and Takata provided a partial response on December 23, 2009. Takata then provided its complete response on February 19, 2010. Takata informed ODI that, after analysis of several ruptured inflators, Takata and Honda initially attributed the defect to handling of the propellant during inflator assembly that could have yielded increased moisture levels that, when coupled with thermal cycling in automobiles over time, could lead to reduced propellant density and overly aggressive combustion during air bag deployment. However, it discovered upon review of inflators returned from the 08V-593 recall campaign, some of which fell outside the manufacturing range when Takata suspected the propellant was exposed to elevated moisture, that the source of the defect was more likely due to problems with a specific compression press (Stokes press) used to form the inflator's propellant. Specifically, the propellant tablets produced by the press were found to be less dense, and therefore more susceptible to overly aggressive combustion during air bag deployment. Takata identified the manufacturing time frame over which the tablets were shown to have less den