Takata Corp (7312.T), which is recalling 34 million defective air bag inflators, has proposed a plan to address concerns about the safety of the replacement parts it is providing to consumers – but the details are not available to the public. A proposed Takata testing plan, which the National Highway Traffic Safety Administration posted to its website on Tuesday, totals 37 pages. Takata’s testing plans attempt to deal with two central questions for regulators, lawmakers and safety advocates: whether the air bag inflators now being used to replace defective parts are safe — and for how long.