By MEAD GRUVER
CHEYENNE, Wyo. (ASSOCIATED PRESS) - A new report by the U.S. Government Accountability Office says despite years of study, the U.S. Forest Service and Interior Department have yet to pin down just how effective their aircraft are at fighting wildfires.
The agencies contract dozens of private aircraft to fight wildfires such as the huge fire burning near California's Yosemite National Park right now.
The contracted aircraft include 120 helicopters and 44 tanker planes of various sizes. Their biggest role is to bomb water or fire-retardant slurry on and near wildfires.
The Forest Service says it's collecting more data on the performance and effectiveness of those aircraft.
The GAO also describes challenges the Forest Service faces in modernizing its aging fleet of large air tankers.
Agency officials say they agree with most of the GAO findings.