Defective manufacturing practices, an unstable chemical, manipulated test data and flawed quality control processes are among the problems that plague Takata, according to three investigations into the Japanese airbag maker that is facing mounting recalls of its products. As Takata grapples with the costs of recalls and replacements, automakers with whom it previously enjoyed close ties are shying away from its products. Premature rupturing of Takata airbags has thus far caused 10 deaths, including nine in the U.S., and more than 100 injuries worldwide. On Tuesday, February 23, a group of 10 automakers that conducted a yearlong review into the Takata issue disclosed that the airbag explosions were caused by exposure to humidity, design and manufacturing problems, and the use of the volatile chemical ammonium nitrate.…