State forestry officials are asking people to keep their remote-controlled drones well clear of fires this season, over fears the tiny aircraft could accidentally bring down firefighting planes and helicopters.

Brian Ballou, a fire prevention specialist with the Oregon Department of Forestry, said the agency is asking drone pilots not to launch their aircraft within five miles of a visible smoke plume.

"If we see any of these going up, we have to shut down all air operations," he told reporters at a media briefing last week in Medford.

Privately owned drones have become increasingly popular in recent years, especially those capable of aerial photography using externally mounted digital cameras. Ballou said that even though most commercially available drones aren't very large, they pose a serious threat to manned aircraft under the right conditions. 

"Our really big fear — and I think it's a realistic one — is if a pilot doesn't see a drone and they (collide), a helicopter or even one of our bombers could suffer a catastrophic failure and crash," he said.

Ballou said a drone being flown last year near the Two Bulls fire near Bend briefly brought firefighters' air operations to a screeching halt. "It did cause the aircraft to set down until that drone was back on the ground," he said.

While no license is required to operate a drone for private, personal use, state and local governments are required to obtain federal licensing before using the unmanned aircraft for official business. Private operators using the drones for commercial purposes also are required to obtain permission from the Federal Aviation Administration, which recently began certifying them for business use.

Ballou said his agency is looking into using drones of its own for firefighting purposes but is still waiting for its operating license. "We want to use them as a scouting tool on active fires," he said.

Ballou said he's not aware of any legal penalty that can be imposed on private drone operators for flying too close to a fire scene.

"We're basically at the mercy of the public," he said. "We just don't want the public to become involved dangerously by flying around our fires."

Reach reporter Thomas Moriarty at 541-776-4471 or tmoriarty@mailtribune.com. Follow him at @ThomasDMoriarty.