Three crew members are dead following the crash of a firefighting air tanker on a training mission in Tahama County Wednesday.

The crash of the Lockheed P-3 Orion 30 miles northeast of Chico has raised new fears concerning the safety of the nation´s firefighting aircraft.

Several fatal crashes of air tankers in 2002 prompted authorities to ground the P-3 Orion planes because of structural flaws.

The three men aboard were pilots for Aero Union Corporation training for the upcoming fire season. They were 45-year-old Brian Bruns of Nevada, 52-year-old Paul Cockrell of Fresno and 41-year-old Thomas Joseph Lynch of Redding.

The National Transportation Safety Board is investigating.