Drones are playing an increasingly important role in fighting wildfires

By Andrew Avitt, US Forest Service, Pacific Southwest Region

Drones – also called UAS or unmanned aerial systems – are playing an increasingly important role in fighting wildfires by supporting operations with aerial ignition and gathering intelligence for firefighters. The greatest benefit drones provide is they can take to the sky when manned aircraft are grounded for pilot safety.

Take, for example the FVR-90, a fixed-wing drone with a 14-foot wingspan capable of traveling at speeds up to 46 mph with a flight time of 8 hours. They are sent airborne just at dusk when other manned flights are grounded. The sky is theirs, and the overhead view they have of the fire is detailed and in real time.

“The way we use UAS now is very much a supplement,” said Justin Baxter, the Forest Service National UAS Operations Specialist. “There are certain times that it’s just not safe for us to utilize manned helicopters or fixed-wing aircraft, like nighttime operations or in thick smoke or high winds.”

The drones that Baxter and his team fly are equipped with cameras that are not your normal cameras. They have multiple types of sensors, including infrared, that allow the team to see through smoke and, at night, see heat signatures, or thermal-based imaging. This allows the identification of areas where fire is still active and new areas where flames have advanced, such as spot fires.

Spot fires occur when embers from the main fire are thrown into the air and pushed by wind until they fall to the ground, starting a new fire. They are notoriously hard to identify because they are small at first and visibility is diminished by smoke. They may occur in hard-to-reach places difficult for firefighters to patrol, like on steep slopes or down in drainages.

“Drones are changing that labor-intensive process to identify these spot fires, especially when an operational area can span hundreds of thousands of acres,” Baxter said. With drones, fire managers and incident management teams can scan large areas quickly and easily identify spot fires that may be a mile from the main fire. That enables firefighters to get in and suppress those new starts before they grow.

“To give you an idea, this drone can detect a 2-inch by 2-inch spot fire from a half-mile away,” said Baxter as he gestured to the imposing drone just to his left minutes before takeoff to fly around the perimeter of the Six Rivers Lightning Complex Fire near Willow Creek, California.

Baxter said that much has changed since 2015 when the agency began the UAS program.  With each passing year, incident management teams have increasingly incorporated the capability into their strategies.

The communication between the UAS crew and firefighters on the ground flows in both directions. The drone may be flying over and see heat in an area and transmit the information to a hotshot crew. Conversely, the hotshot crew can ask the UAS crew for assistance in exploring an area that they suspect might be active, and then view a feed from the drone of the area in question.

John Crotty served as the air operations branch director with California Interagency Incident Management Team 15 that responded to the Lightning Complex Fire on the Six Rivers National Forest.

Aerial intelligence isn’t new in wildland firefighting, said Crotty referring to the recently retired Cobra helicopter and its Firewatch capabilities. But the implications of unmanned flight— that opens up new possibilities.

“With the Cobra aircraft, we needed a pilot and an interpreter up there to run the camera and talk to the folks on the ground. So, we expose two individuals plus a flight [to risk],” said Crotty, “But what we really needed was the visibility to fly.”

Thick smoke on the fires like the Lightning Complex can ground manned aircraft. That’s where drones come into play and the images it captures can inform firefighters working across a large area.

“The other day I heard from one of the hotshot crews out there. They were in heavy smoke conditions, at night. With the low visibility they couldn’t see if they had a spot fire across the line,” Crotty said. “This tool being up in the air, looking down at that exact area, the UAS crew was able to pinpoint the spot and provide precise coordinates to the firefighters who were able to check it out and put it out. That kind of information we would never have without these unmanned aircraft and that capability. Drones are the future of aviation for not only fire but for aviation in general. It’s a win-win for the agencies to operate under an umbrella of this type of aircraft that can provide precise and timely info to firefighters and incident management teams. And most importantly, we can do it safely.”