Takata Corp. said this week it plans to double its capacity to manufacture replacement air bag inflators within the next six months in order to meet demand for recalled vehicles.

The Japan-based supplier said it expects to produce about 900,000 replacement kits each month by September. The company currently manufactures about 450,000.

About 17 million vehicles have been recalled in the U.S. because of Takata’s defective air bag inflators.

Meanwhile, the 10 automakers whose vehicles are part of the Takata recalls said they have jointly hired aerospace firm Orbital ATK to investigate the causes of the Takata air bag inflator explosions. Additionally, the companies selected David Kelly, a former head of the National Highway Traffic Safety Administration, to manage the project.

The automakers are BMW, FCA US, Ford, General Motors, Honda, Mazda, Mitsubishi, Nissan, Subaru and Toyota.

The investigation will include a close look at the use and impact of ammonium nitrate as a propellant in the air bag inflators. The defective inflators, which can explode and send shrapnel flying, have been linked to several deaths and injuries.

In a released statement, Takata pledged support for the automakers’ investigation and said the company would share its own test results.

Under NHTSA oversight, Takata is testing the air bag inflators to determine the scope of the defect and to search for the root cause.

NHTSA said it has also hired an outside expert to “examine the range of possible root causes, help monitor testing and advise the agency on any additional actions we should take.”

Communications between the federal agency and Takata have been strained, to say the least. On Feb. 20, NHTSA began levying $14,000 a day in civil penalties against Takata for failure to respond to requests for information about more than 2.5 million pages of documents the company provided under NHTSA orders. 

To view a Bloomberg video clip in which U.S. Transportation Secretary Anthony Foxx explains what prompted the fine, click here.

On Feb. 25, NHTSA issued an order requiring Takata to preserve all air bag inflators removed through the recall process so the parts could serve as evidence for both NHTSA’s investigation and private litigation cases. 

“The order also ensures NHTSA’s access to all data from the testing of those removed inflators,” the agency said in a released statement. 

“This department is focused on protecting the American public from these defective air bags and at getting to the bottom of how they came to be included in millions of vehicles on U.S. roads,” Foxx said. “This preservation order will help us get the answers we need to accomplish those goals.”

The order calls for these key provisions: 

• Takata is prohibited from destroying or damaging any inflators, except as is necessary to conduct testing.

• Takata is required to set aside 10 percent of recalled inflators and make them available to private plaintiffs for testing.

• Takata is required to submit for NHTSA’s approval plans for gathering, storing and preserving inflators already removed through the recall process and inflators removed in the future. The company also must submit to NHTSA the written procedures for making inflators available to plaintiffs and automakers who request access.

• Plaintiffs or automakers who seek access to inflators must submit to the terms of the preservation order, which grants NHTSA access to all testing data.

• NHTSA retains the ability to collect inflators for its own testing if it determines such testing is necessary.

“We have worked closely with attorneys for private plaintiffs to construct this order so that it protects plaintiffs’ legal rights while also supporting our efforts to protect public safety,” said NHTSA Administrator Mark Rosekind. 

Read the preservation order