Authorities briefly grounded a U.S. Forest Service reconnaissance plane flying over a series of small wildfires in Northern California after a drone flew too close to the scene.
The Forest Service says the plane was grounded for about an hour and a half for safety reasons on Monday near Redding. The owner of the drone was not found.
It was the third time in less than a week that the spotting of a drone over a California wildfire prompted the Forest Service to order planes to land for safety reasons.
Officials fear the drones will collide with firefighting planes. Two tanker planes dropping retardant on a large wildfire in San Bernardino County, 90 miles east of Los Angeles, were briefly grounded June 24 and 25 when drones were spotted over the blaze.
The Forest Service is calling on owners of unmanned aircraft to keep the drones away from wildfires. No accidents have been reported because of drone interference, Forest Service spokeswoman Heather Noel said.
"But it's a growing trend," she said.
Firefighting aircraft often fly low in the same airspace as drones. Federal authorities often place temporary restrictions on air travel near wildfires, and drone operators flying without permission over the blazes face fines, Noel said. The Forest Service said there's a potential for "smokejumpers," firefighters who parachute into remote areas, to collide with drones as well.
"These instances in the last week with (drones) are a reminder that there is potentially a new hazard in the fire environment," said Josh Mathiesen, a U.S. Forest Service smokejumper base manager. "And that is really something we do not need. I do not want my smokejumpers to be focusing on drones flying around. I want them to focus on getting safely to the ground and suppressing the fire."