WISCONSIN—An interagency firefighting team aided by a fire drone conducted a highly successful prescribed burn in central Wisconsin on Department of Defense land, April 11.

The DoD, Wisconsin Department of Natural Resources, Chequamegon-Nicolet National Forest, The Nature Conservancy, Blackwell Job Corps Center and USDA Forest Service Eastern Area Regional Aviation staff took part in the operation held at Hardwood Range on Air National Guard land near Necedah, Wisconsin.

The Forest Service served as the lead agency with participating agencies embedded in all levels of the prescribed fire operation. About 45 personnel in total took part in the effort which safely burned approximately 2,150 acres of vegetation.

Ryan Mungall, Eastern Region Fire Unmanned Aerial Systems program manager, operated a Freefly Systems Alta X drone during the prescribed burn to start small fires within the prescribed fire area.

The Alta X differs from recreational drones by including a payload delivery mechanism that drops ping pong-like spheres filled with potassium permanganate that is injected with glycol. These spheres ignite on the ground when dropped. After the UAS drops these spheres over the burn area (approximately 30 seconds later) a chemical reaction occurs, starting small fires, Mungall said.

Traditionally, there are two main methods for prescribed burns, hand ignition or helicopter dropped ignitions. Using a drone instead of a helicopter or human fire igniters on the ground helps reduce costs, risks to flight crews and reduces the risk exposure to ground personnel who would normally be doing firing operations.

“It’s a risk transference from humans to machines. If the drone breaks, that’s just equipment,” Mungall said.

Chequamegon-Nicolet National Forest Fire Management Officer Lee Jensen praised the use of drones for prescribed burns. “The delivery method increases the likelihood of a mosaic burn pattern, an ecologist’s dream.”

“You’re getting a more representative ignition pattern to the landscape,” Jensen added. “For instance, wet areas will be less likely to burn, and drier ones will be more likely. In this case some drier areas didn’t burn, thus sheltering flora seed banks to propagate into the burn areas.”

Prescribed burns reduce invasive plant species, increase native plant diversity, and reduce the risk of catastrophic wildfire by removing dead vegetation, Jensen said. “They are a natural thinning mechanism for young, even aged stands.”

Prescribed burns also reduce tick borne illnesses and allow fire professionals to come together to practice their trade. “It lets us burn the area under more controlled circumstances when we want to, as opposed to during an uncontrolled wildfire event,” he added.

Chequamegon-Nicolet Forest Supervisor Jenn Youngblood said, “It was wonderful to see all of the firefighting professionals come together at a well-planned, and successfully conducted prescribed burn. The ongoing relationship between the DoD and the USDA Forest Service is beneficial to the residents of Wisconsin in managing landscapes for not only ecological restoration and management of invasive species but to keep our local communities safe from potentially uncontrolled fires in the future. I want to thank everyone involved in this prescribed burn for their service to the public and to residents for their interest in this event as we strive to keep communities safe.”