Forest Service Chief Dale Bosworth and Bureau of Land Management Director Kathleen Clarke announced that three DC-4 large air tankers would not be returning to federal firefighting service in 2004 because inadequate information exists to determine an operational service-life limit for these aircraft.

The information on the service life for the DC-4 is key to determining the safety of these aircraft.

The operational service life is expressed in how many hours an aircraft can be flown safely according to the original equipment manufacturer. It takes into account the stresses imposed on the airframe during different flight maneuvers. The agencies are currently in discussions with the OEM to determine if the data needed for an engineering study to establish a service-life limit exists and are available. The aircraft were produced in the 1950s by McDonnell-Douglas, now a part of Boeing Corp.

The report from Dyncorp Technical Services indicated that the contractors did not have enough data to provide to Dyncorp to determine the service life. The DC-4 large air tankers are owned by ARDCO Inc. of Tucson, Ariz.

For further information contact Rose Davis or Randy Eardley, National Interagency Fire Center, at 208-387-5437 or 208-387-5895.