Owners may need to have Takata air bags replaced more than once

Millions of owners of vehicles equipped with Takata air bags may have to get repairs done more than once because of shortages of replacement parts and uncertainty over whether repair parts already installed are defective, auto industry officials and safety regulators said on Tuesday.

A House subcommittee has scheduled a hearing for 2 p.m. EDT on Tuesday as part of an investigation of problems with Takata air bags that have been linked to six deaths and one of the largest consumer product recalls in U.S. history.

Lawmakers are expected to look at when owners of affected vehicles, which could number as many as 34 million in the U.S., can be sure that their air bags are safe.

"Because of the size and scope of the recall, a replacement part may not be immediately available," said Mark Rosekind, head of the National Highway Traffic Safety Administration, in written testimony ahead of the hearing.

Automakers are concerned that a lack of available replacement parts might cause many consumers to ignore the recall.

The problem has taken on increasing urgency this year as Takata has continued to expand the list of potentially defective air bags.

The inflators in those air bags are prone to rupture and send shrapnel into vehicle occupants. They have been linked to hundreds of injuries, according to NHTSA.

Ten passenger-car manufacturers since 2008 have announced recalls involving ruptured inflators in Takata air bags, and their dealers have been replacing the affected parts as they have become available from the company and, more recently, other suppliers.

Takata last month said certain air bags that already have been repaired may need to have parts replaced a second time.

Another complication is that the recall involves both driver- and passenger-side air bags. Neither Takata nor NHTSA can say how many vehicles in total may be affected or how much overlap there may be.

Because a defect exists in both types of air bags, it means "we need two replacement inflators (and) the owner probably needs to make two trips to the dealer," NHTSA said Tuesday.

The House subcommittee on commerce, manufacturing and trade will hear testimony from Takata executive Kevin Kennedy and representatives of two vehicle manufacturer trade groups. Also scheduled to appear is David Kelly, a former NHTSA acting administrator who was hired to lead an independent investigation by a coalition of the 10 automakers using Takata air bags.

(Reporting by Paul Lienert in Detroit; Editing by Lisa Von Ahn)