There´s a new development in the debate over using air tankers to fight wildfires.

Some large air tankers that were grounded last month because of safety concerns may be back in the air in time to fight wildfires this summer.

Federal officials say the planes may be cleared for use if their private operators can prove they´re safe.

The Forest Service grounded the 33-plane fleet, citing safety concerns about the aging aircraft.

Two planes broke up in midair in 2002, killing five people.

But officials say new guidelines have been developed to assess the planes´ air worthiness.

A Forest Service official says private operators will be asked to supply detailed records showing each plane´s flight history, along with its maintenance and other information.