BILLINGS, Mont. (AP) — Montana’s firefighting aircraft have returned to duty as fire officials sought even more personnel and aircraft ahead of a shift in the weather that could stir up a large fire on the Wyoming border. Critical fire weather conditions are predicted in southern Montana and northern Wyoming through Saturday evening. A helicopter crash earlier this week grounded the Department of Natural Resources and Conservation’s fleet as major wildfires broke. State and government data show almost 55 square miles have burned in Montana so far in 2021. The vast majority burned in human-caused fires.