Firefighting aircraft and helicopters: The flying fire brigade

Forest and bush fires have been around for as long as those landscapes have existed. But never before in recorded human history has our planet seen such widespread and intense wildfires. Since the summer of 2023, it’s been possible to scientifically quantify this trend. A team from the University of Tasmania used satellite data to analyze the energy of major fires between 2003 and 2023. They identified 2,913 extreme fires that between them released more energy than 99.99 percent of all the fires investigated during this period. Over time, the number of extreme fires rose from around 100 per year to more than 200. While the total energy of the 20 most serious fires in the first year was around 60,000 megawatts, 20 years later it was more than 130,000 megawatts. According to the study, fires have increased everywhere, but most notably in the Arctic and subarctic forests of the northern hemisphere and in the coniferous forests of temperate latitudes.

Best keep firefighting aircraft and helicopters ready for takeoff

This comes as no surprise to Alexander Held, Senior Expert at the European Forest Institute in Bonn, Germany. “Climate change is making extreme weather more frequent, leading to more extreme fires: increasing drought provides more and more fuel for forest fires, so they become hotter, bigger, and more intense.” This is making firefighting increasingly difficult. Especially in areas that are more difficult to access, or where there is an extreme danger of forest fires, firefighting aircraft and helicopters are the only option for a truly rapid first attack. To be able to get to the source of the fire as quickly as possible, it’s best to keep the aircraft parked on the runway, fueled and ready for takeoff. Better still is to have them already in the air on patrol.

Chemicals make the water gel-like, dyes make it visible

Whether in a firefighting aircraft or a firefighting helicopter, the crew can’t simply switch to autopilot. Where fire rages, hot air rises, meaning the flying firefighters often have to deal with bone-rattling turbulence. In addition, smoke and fumes impair their visibility. As a result, tragic accidents occur time and again, often with fatalities among the crew.

The aircraft take on water either at their home airport or on their way to fight the fire. The latter involves perilous maneuvers as pilots bring their firefighting aircraft into direct contact with the surface of a lake or the sea to literally scoop the water into their tanks. Helicopters hover over the water and drop their external tanks, which are usually suspended from ropes, down into the water.

As a rule, flying firefighters add chemicals to the water to give it a gel-like property that allows the water to adhere better to trees and bushes. Compounds based on ammonium phosphate deliver an additional cooling effect. Adding often brightly colored dyes helps pilots identify where water has already been dropped.

Virtual-reality training for aerial firefighting or rescue exercises

But without support on the ground, fighting wildfires from the air won’t achieve much. “The crucial thing is that, before anything else, we do our homework in fire management on the ground,” Held says. In commercial forests, that starts with the choice of tree – a key consideration. Resin-rich conifers, especially pines, burn particularly well. That’s why the owners of large pine forests often rely on firebreaks formed by poplars, robinia, or red oaks. Tracks through the forest that provide access for forestry machinery have a similar effect. But regardless of their preventive function, it’s essential to maintain these forest tracks. After all, if a fire does break out, the firefighters on the ground need to get to it as quickly as possible.

The surest path to containing a wildfire is when air and ground forces act in a coordinated manner. Which fires would require enormous effort to reach using hose lines and are therefore better fought from the air? When does it make sense to hastily cut new firebreaks in the forest? And exactly when and where should airborne firefighters drop their water? Any firefighters on the ground need time to withdraw so they can avoid the danger of trees toppling under the weight of the water being dropped from the air. If helicopters have filled their external tanks in shallow lakes or riverbeds, the water they dump out of the sky can contain stones.

Fighting fires with high tech: Modern approaches to managing wildfires

These days, cutting-edge technologies and innovations have become commonplace in forest firefighting. Infrared sensor technologies on drones – or, in remote areas, via satellite – enable the early detection of fires, often before the flames are visible to the human eye. AI and machine learning can help analyze and process large amounts of data, such as satellite photos, weather forecasts, or readings from temperature sensors distributed throughout the forest. These technologies help either in predicting the probability of fires or in correctly interpreting early warning signs. Once a fire has broken out, they help monitor its spread. Virtual-reality training also provides valuable assistance in aerial firefighting training, rescue exercises, and wildfire scenarios.