Technology: Fireball-dropping drones and the new technology helping fight fires
As unprecedented wildfires ravage California and much of the West in the US, fire fighters have taken innovative steps to try to keep up with the flames. An array of new and existing technologies has been pulled into the fray including fireball-dropping drones and repurposed passenger jets, to enhance ground-based, time-tested techniques. Fighting fires still depends on cutting firebreaks, setting backfires and spraying water. The best tools are often simple ones: water hoses, bulldozers, brush-clearing axes. However, in an age where climate change is promoting more and bigger fires that consume millions of acres in a single season, the profession of fire fighting must be quicker, safer and cover greater ground, even as a spreading pandemic makes the work that much harder. Because of their size and manoeuvrability, drones can access places that fixed-wing aircraft and helicopters can’t, making them arguably the greatest innovation in fire fighting this year. At least 30 pilots guiding some two dozen drones are fighting wildfires in Oregon, California, Colorado and elsewhere. That’s twice as many as last year, when the federal Wildfire Management Technology Act was signed into law to allow more drones to be used to fight wildfires. “We’re getting a significant increase in requests this year. We don’t have the pilots or aircraft to meet the needs now,” says Joe Suarez, a drone specialist with the National Park Service and superintendent of the Arrowhead Hot Shot fire crew in California’s Sierra Nevada mountains.
In August, Suarez was flying an M-600 drone over the Woodward Fire on the Point Reyes National Seashore. He was using the six-rotor aerial vehicle, equipped with thermal imaging, to map the fire, which covered 5 000 acres then. Human-piloted aircraft could not risk flying into the coastal fog and the smoke.
Simon Weibel, another longtime fire fighter who now works for a company called Drone Amplified, joined Suarez that day. He brought along a funnel-shaped attachment for the underside of a drone, a device that can release 450 ping-pong-ball-sized incendiary devices in less than four minutes.
Each of the one-inch spheres, called Dragon Eggs, contains potassium permanganate and just before they are released they are given a pin injection of anti-freeze. The reaction between the two chemicals ignites the spheres after they hit the ground. The eggs can set fires ahead of an advancing wildfire in hard-to-reach places, denying it fuel.
“A bonus is you can do nighttime ops and work in smoky conditions, because if a drone crashes, no one dies,” Weibel notes.
At the Point Reyes fire, the drones were “a good safety tool for getting in where it was too thick or too steep for the fire fighters,” says Suarez. And the Dragon Eggs they dropped enabled the backfire to cover a strip of land that was 300 to 400 feet wider, which made it a much more effective barrier against the spread of the wildfire.
Big help from above
Above the deadly El Dorado Fire burning east of Los Angeles in September, a retrofitted 747 Jumbo Jet flying low over the treetops released 18 000 gallons of bright red fire retardant to slow the progress of the fast-moving wildfire. Leading the jet was a highly manoeuvrable, Vietnam-era OV-10 Bronco plane. Before guiding huge planes with huge loads of fire retardant, these Broncos make sure the jet’s path is clear, that no updrafts, shifting columns of smoke, hidden terrain or other obstacles could place the massive aircraft and its three-person crew in danger.
Another potential danger for fire fighting aircraft is unauthorised civilian drones, experts say, since low-flying fire fighting aircraft are automatically grounded whenever these drones are spotted. “Our planes and helicopters are operating just a couple hundred feet above the ground, leaving no room to manoeuvre if a drone appears,” explains Cal Fire public information officer Scott McLean.
Seated behind the pilot in the Bronco’s tandem cockpit is a Cal Fire expert who has six radios to stay in touch with other fire fighters, agencies, the media and airport control towers. Above the observer aircraft, which can circle the flame and smoke for up to three hours at a time, a number of other technologies work at the strategic level.
Satellites owned by NASA, the European Union, the military and other agencies are helping identify and track new wildfire outbreaks with cameras and sensors that can see in different wavelengths. The US Forest Service and US Geological Survey have long used Earth-observing satellite data to help model and predict where future wildfires might break out. But fire behaviour specialists are warning that the old models may no longer apply to today’s hotter, faster, larger fires.
“When you burn 1,5 million acres in two weeks,” notes Cal Fire scientist David Sapsis, “that kind of fire event is unprecedented.”
In early September, a NASA Gulfstream jet with an imaging radar slung in a pod on its belly flew over Northern California’s LNU Lightning Complex Fire, which decimated parts of wine country. Peering through the smoke, the radar produced a close-up, high-resolution picture showing how the fire was moving across the landscape. “This instrument is very versatile in allowing us to detect soil moisture and vegetation structure and biomass,” says Yunling Lou, who manages the radar programme out of NASA’s Jet Propulsion Lab in Pasadena.
The JPL radar can penetrate smoke and clouds and measure ground height to within a quarter inch. That enables it to provide real-time mapping for fire management teams, as well as to map fire damage. It can also track which burn areas are most susceptible to landslides and debris flows during the rainy season, as happened with the Montecito mudflow of 2018 that killed 23 people and injured 163.
California’s Air Force
Cal Fire has the largest fire fighting air fleet in the world. At present it includes 56 state-owned and 11 leased aircraft. Based out of the former McClellan Air Force Base near Sacramento and with 22 air stations up and down the state, Cal Fire can be over a newly reported fire within 20 minutes. The aircraft can observe the fires, dispatch “Helitack” firefighting crews from helicopters, as well as release water and fire retardant.
The Cal Fire Firehawk, a new helicopter, is faster, so pilots can fly fire fighting teams more quickly to new fires. The Firehawk can also drop 1 000 gallons of water, three times as much as older helicopters and then use its retractable snorkel to refill its tank from the nearest body of water.
Another major technological upgrade to the helicopter fleet is night vision goggles for the pilots, long used by the military. This will allow the Firehawks to do tactical flying, fire fighting, and rescues in darkness. In early September, the goggles, which can also peer through smoke, made it possible for the California Air National Guard to rescue over 200 trapped campers from the Creek Fire.
The next tech?
Given how quickly drones have been adopted for fire fighting, it seems certain we’ll be seeing flocks of them over wildfires in the next few years. But Dennis Brown, Cal Fire’s senior chief of aviation, is quick to admit that, critical as aircraft are, “it’s boots on the ground that put out fire.”
And it’s today’s frontline fire fighters, heavy equipment operators, and fire incident managers who will decide the right tools and direction to improve fire fighting.
During the past five to 10 years, many crews have begun packing smoke-penetrating thermal-imaging cameras that are useful for spotting fire movement and hot spots otherwise hidden by heavy smoke, providing added safety. Materials science has also offered fire fighters some relief, by creating lighter and more durable flame-resistant and breathable clothing. It has dramatically reduced heat casualties in areas where summer temperatures can top 37°C even before anything catches fire.
Asked what new technology he’d like to see next, Suarez suggests better communication tools to safely operate in the smoke. “When I was in the Navy we had something where the whole fleet could see where everyone was and what they were doing. It’d be nice to have a (ground-based) system where we know where we all are and communicate better with live video to help us with our decision-making and our situational awareness,” he said.
Source: National Geographic