Wildfire drone operations have moved beyond the question of whether an unmanned aircraft can find heat or provide an overhead view. The harder problem is fitting another aircraft and another stream of data into an incident that may already involve helicopters, air tankers, lead planes, ground crews and changing airspace restrictions. For response professionals, useful drone work starts with aviation integration, disciplined mission planning and a clear path from observation to action.
Airspace Coordination Comes Before Sensor Capability
Temporary Flight Restrictions (TFR) around active wildfires are intended to protect firefighting aircraft and crews. Unauthorized drones can interrupt crewed aviation, yet authorized public safety flights still have to fit inside the same incident aviation structure. A technically successful mission can become an operational problem if the aircraft location, altitude or flight window conflicts with a helicopter or tanker assignment.
Authorized drone operations on active wildfires already work within established incident command and aviation structures. The challenge is maintaining that integration as UAS missions become more frequent, longer-range and increasingly complex. A drone may be operating under incident authority, but its flight area, altitude, timing, communications and data requirements still have to remain aligned with changing crewed-aircraft operations throughout the operational period.
For that reason, UAS coordination should extend beyond initial flight approval. Flight areas, altitude limits, lost-link procedures and an immediate grounding process need to be understood before launch and reviewed as incident conditions change. TFR and NOTAM (Notice to Airmen) information can also change during an operational period, so a single preflight review is not enough for a long mission cycle.
Key operating priorities include:
Define operating areas and altitude limits before launch.
Keep direct coordination between Unmanned Aerial Systems (UAS) personnel and incident aviation staff.
Recheck TFR and NOTAM information as conditions change.
Give aviation supervisors clear authority to stop unmanned flights when crewed aircraft need the airspace.
Beyond Visual Line of Sight (BVLOS) missions can extend observation beyond practical ground access, but range brings new problems. Communications reliability, aircraft tracking, detect and avoid methods and lost link behavior become part of the safety case. More distance is useful only when the incident team can still account for the aircraft and control the mission.
Image created by ZenaDrone
Thermal Imaging Has Limits That Matter on a Fireground
Thermal imaging can support hotspot searches, perimeter assessment and detection of residual heat. The risk is treating a thermal image as a final answer. Vegetation, terrain, sensor angle, smoke, heated surfaces and distance can change what the operator sees. A bright signature may need field confirmation, and hidden combustion may remain difficult to characterize from one aerial pass.
Repeated observations tied to coordinates are often more useful than a single image. The operational question should be simple: what decision will this flight support? A drone that detects heat outside a containment line may provide valuable intelligence. That value drops very quickly if the location remains on the pilot display and does not reach the people assigning resources.
Endurance and Night Operations
Battery endurance is another practical constraint, particularly across large incidents. Published flight time matters less than usable mission time after wind, distance, payload, reserve requirements and repeated recovery cycles are considered. Crews may spend a surprising amount of the operational period managing batteries, charging and launch locations rather than collecting data.
Night flights can support thermal observation during periods of reduced visibility, but darkness changes the risk picture. Terrain references become harder to judge and recovery may require more planning. Night activity still needs to remain coordinated with other aviation. It cannot be assumed that the absence of daylight means the airspace is available.
Data Integration Is the Larger Opportunity
Wildfire agencies already collect large amounts of information. Drones can add thermal images, video, maps and coordinates at a pace that becomes difficult to use. The real objective is not collecting more data. It is moving a smaller amount of verified information to the right person soon enough to influence a decision.
Different agencies may arrive with different mapping platforms, radio systems and data procedures. This can make a simple location report harder to share than expected. Incident teams benefit when drone outputs use common geospatial formats and when responsibility for validating and distributing UAS intelligence is defined in advance.
Autonomous docking stations may make repeated observation easier by supporting automated launch, recovery and charging. They still require reliable communications, weather limits, updated airspace information and a clear way to interrupt a mission when incident priorities change. Autonomy can reduce routine workload, but it does not remove accountability to incident command.
The strongest wildfire use of drones is likely to come from integration rather than aircraft quantity. Better airspace deconfliction, disciplined thermal interpretation, practical BVLOS procedures and interoperable data sharing can make UAS missions more useful without adding unnecessary risk. Wildfire response does not need drones flying simply because they are available. It needs missions with a defined purpose, controlled access to the airspace and a direct connection between observation and action.
Usama Mehboob is a Content Writer at ZenaDrone Inc, covering drone technology, its applications and related industry developments.More at www.zenadrone.com/wildfires/
A new and improved Bell 214ST helicopter will soon roll off the production lines with McDermott Aviation announcing the restart of manufacturing after more than 20 years for one of the main workhorses of disaster response worldwide.
McDermott Aviation is announcing the move at the Verticon aviation conference in Atlanta, US, this week. Australian-based McDermott Aviation claims the title of the world’s largest operator of the Bell 214 Series helicopters, which is a stable feature in many firefighting fleets in the Asia Pacific, Asia, North America and Europe.
Bell 214ST ‘Super transport’ helicopter. Photo: Vasilis Kranitsas.
McDermott Aviation’s ownership of the Type Certificate for the 214ST platform enables it to revamp it for the needs of modern aerial firefighting, heavy lift logistics and disaster response, and meet the certification requirements of operators worldwide.
The 214ST was originally conceived for military use at the request the Shah of Iran in the late 1970s. But with the overthrow of the Shah in 1979, Bell switched the concept to civil use and produced the first production models in 1982.
The 214ST proved to be a strong and reliable workhorse for heavy lift tasks, being capable of carrying up to 19 firefighters or passengers – ST is for Super Transport. The last 214ST was built in 1993, which means all the current aircraft in operation are well into their third decade of use or more.
Founder and President of McDermott Aviation, John McDermott, told Wildfire Today from Atlanta that his company have been improving and modifying the 214ST since its first purchase in 2012.
“They are now so popular that there are no more available on the market. We thought, well, we have got to manufacture spare parts for our helicopters why not just start building more helicopters? We have had massive support throughout the world for that. The aerial firefighting market is short of good utility helicopters that can actually do the work.”
McDermott Aviation Founder and President, John McDermott
We thought, well, we have got to manufacture spare parts for our helicopters why not just start building more helicopters?
john mcdermott
The McDermott 214ST is a twin-engine heavy utility helicopter currently powered by GE CT7 engines, capable of lifting external loads of up to 7900 pounds/3700kgs, with a cruise speed of up to 160 knots and a range exceeding 300 nautical miles. Future variants of the aircraft will incorporate the latest-generation Safran ANETO family power plants, delivering better performance, efficiency and reliability.
Delivery slots for a modified aircraft are expected to begin from 2027, with factory-new aircraft with the new airframes, engines and avionics targeted for 2028–2029 production timelines. Components will be made in various jurisdictions with the final assembly in San Bernadino, California. McDermott Aviation is based on the Sunshine Coast in Queensland but plans to manufacture components there are stalled.
”We are manufacturing in America. We would like to manufacture in Australia too but CASA [Civil Aviation Safety Authority] make it so impossible to do anything,” McDermott told Wildfire Today.
“What’s particularly interesting about this program is that it’s essentially the rebirth of a tried and proven helicopter,” Mr McDermott said.
“As the new manufacturer, we have the unique advantage of being able to incorporate all the improvements that have emerged over more than 40 years of operational experience.”
The death of two firefighters and the loss of around 40 homes have marked the effective start of the bushfire season across southern Australia and the active engagement of the national aerial firefighting fleet.
Milder conditions today have provided both New South Wales and Tasmania with some respite from extreme fire activity and the opportunity to strengthen containment lines before the heat returns.
Western Australia has had an early hectic start to the season with numerous warnings for fire, storm and heatwave across the vast state. The arrival of a C-130 this week to bolster its 38 aerial firefighting fleet has been welcomed.
The National Aerial Firefighting Centre has 161 aircraft filling 175 services across the country this summer.
Six LATs and 17 Large helicopters are on NAFC contracts this season. Their homebases are in Queensland, New South Wales, Victoria, South Australia and Western Australia. While they are located and managed by the home jurisdictions, the NAFC contracts allow them to be shared across borders.
C-130 Hercules, part of the national aerial firefighting fleet 2025. Photo: NEMA
Australian Government funds of $100 million over 2024-25 support the NAFC fleet. Additionally, the grant funds the minimum costs of five national aircraft that are dispatched under the protocols facilitated by the National Resource Sharing Centre. This collaboration allows the Chiefs and Commissioners nationally to decide where these national aircraft can be placed so that they can be mobilised easily to the jurisdiction that has the greatest need. These five aircraft are on contract and in position now.
One National LAT is based in New South Wales, along with its Cessna Birddog aircraft
One National S61 multi use RW, also based in NSW
Two National Blackhawks are based in Qld and South Australia
Eight aircraft in the fleet have complementary contracts with North American agencies and follow the fire season to Australia every summer. Their Australian start dates are staggered across the country and all aircraft are in position in time for their contracted starts.
Further information about the NAFC fleet and its contracted operators can be found on the NAFC website Fleet.
The death in late November of a National Parks and Wildlife Service South Australia brigade strike team member working as a firefighter with the Country Fire Service while undertaking remote firefighting on the Eyre Peninsula and the death on the weekend of a New South Wales Parks and Wildlife Service firefighter, plus the loss of more than 40 homes in both New South Wales and Tasmania have woken many to the start of the bushfire season across southern Australia. A farmer also died protecting his property in a fire in the south-west of Western Australia in early December.
The NSW NPWS acknowledged the loss in a public statement share on social media:
“It is with immense sadness that we confirm the death of a National Parks and Wildlife Service firefighter while working at a fireground south of Bulahdelah on Sunday night.
Our thoughts are with the firefighter’s family, friends and colleagues, including those from NPWS and NSW Rural Fire Service who were working alongside him.”
In the past week, fires at Koolewong and Bulahdelah in New South Wales destroyed 20 homes and a natural disaster has been declared in several local government areas, while wind-driven fires at Dolphin Sands along the picturesque east coast of Tasmania razed 19 houses and damaged dozens more.
While in November the Bureau of Meteorology confirmed a La Nina to welcome in the summer, it came with the qualification that the wet and cool weather may be brief. The heat well and truly arrived in December and, coupled with the fuel growth and long-term rainfall deficiencies in many regions, the bushfire summer began with several days of heat and wind.
Prime Minister Anthony Albanse has warned Australians of a “difficult” season ahead, with New South Wales in particular danger. He told ABC television:
“This summer, of course, like all summers that would appear in recent times, is going to be a difficult one. But New South Wales in particular has a range of preconditions, if you like, for being quite a difficult one.”
Research and experiments on airdrops in France began with the first LABEX (LArgage Bombardier d’eau EXperimentation) experiment in 1995.
Following the acquisition of CL-415 waterbombers by the French government, it quickly became apparent that to optimize aerial firefighting, it was necessary to understand the dropping characteristics of the aircraft.
Entente Valabre, the laboratory of the French Securité Civile, oversaw measuring the ground patterns of the French waterbomber fleet.
The aim of the LABEX research is to determine the ground patterns of various water-bombing aircraft and analyze the ground distribution of the released product by application rate class.
Each aircraft comes with a range of dropping programs. To optimize aircraft use in aerial forest fire fighting, it is essential to know the surface areas covered by the different applications – how much area is covered and by what depth of drop.
To complement these experiments at a real scale, with real aircraft, other experiments are carried out to understand and model aircraft drops are conducted. Analysis by Entente Valabre researchers of the airtanker ground patterns show that the product is not deposited uniformly, and is often deposited very irregularly, because of a complex fragmentation process of the liquid column released by the aircraft.
Although the release process seems simple, the fluid dynamics governing the transformation of a liquid block into a cloud of droplets are only partially understood. The droplets can be neither too fine to avoid dispersion and evaporation, nor too large to avoid harsh impacts on vegetation and the ground, resulting in projected objects. Large-scale fragmentation of a drop, which leads to the formation of liquid meteors that take longer to atomize into droplets, is a complex process and its physical origin is unexplained.
DETERMINATION OF GROUND PATTERNS
Ground patterns are evaluated on flat test areas, free of vegetation or covered only with herbaceous vegetation up to a height of 20 centimetres.
The test area dimensions are determined according to the aircraft to be tested and the areas is set up in a grid. The drop patterns are measured by distributing receptacles over the test area, comprising a fixed support and a collection cup designed to catch the liquid. After each test, the cups are hermetically sealed, collected and weighed. Each pattern is then plotted on a predefined scale, corresponding to classes of application rate in litres per square metre per day, or litre/metres².
Various camera views of retardant drops show specific factors that help to determine effectiveness. Photo courtesy of Entente Valabre.
DETERMINING RELEASE EFFICIENCY
The ground-pattern efficiency is primarily related to the application rates obtained, depending on the product released – water or retardant. In the Mediterranean region, under normal conditions of vegetation (10 metric tonnes per hectare), weather (wind less than 60 km/h) and terrain (not generating excessively difficult trajectories or significant turbulence), a rate of 0.8 lm2 is representative of an effective release using long-term retardant, while a rate of 1.6 l/m2 is representative of an effective release using water.
The various ground patterns parameters are:
The length and depth for coverage rates above the representative application rates
The area and product volume above representative application rates
The homogeneity of the ground pattern
The difference between the time the drop hits the ground and the time it totally covers the ground.
Ground pattern extension and concentration levels are not the only release characteristics that can determine the effectiveness of a drop. The speed of the released product can have a considerable influence on breaking fire-induced updrafts during direct attack, on upwind accuracy, or on safety on the ground. All these factors can be qualitatively related to the phases of ground-pattern formation. The three phases – retardant cloud tearing, atomization and dispersion – explain the various stages that take place between the initial break-up of the product cloud and the formation of droplets that have reached their final size. The rheology of the product, the height and speed of the aircraft, and the release system play an important role in these phenomena.
Observation of the drop is very important to assess its effectiveness, and valuable information can be gleaned from camera images. For this reason, a few subjective criteria are selected:
The status of the cloud when it hits the ground and the way it disperses while resting on the ground.
The drop patterns are measured by distributing receptacles over the test area, comprising a fixed support and a collection cup designed to catch the liquid. After each test, the cups are hermetically sealed, collected and weighed.
PRESENTATION OF RESULTS
The ground patterns are presented in the form of summary sheets in which the following are described:
technical flight data (altitude, aircraft speed)
technical loading data (weight, volume)
meteorological conditions
ground patterns characterization.
Following these analyses, recommendations are made regarding the use of different dropping programs for specific firefighting missions, for example initial attack or retardant barrier construction.
EXPERIMENTAL CAMPAIGNS IN FRANCE
Five experimental campaigns have been conducted in France:
A liquid drop in the wind tunnel at the Institut wind de Mecanique des Fluides de Toulouse and computational fluid dynamics of a Canadair CL-415 drop. Images courtesy of Entente Valabre.
LABEX campaigns are time consuming and costly; therefore, it is essential to have a dropping model that can be used to vary, for example, the height of the drop, the wind direction and the characteristics of the product released – questions that water bomber pilots frequently ask to understand and optimize their practice.
With this in mind, a team at the Institut de Mecanique des Fluides de Toulouse is developing a dropping model that has already been tested against results obtained during various LABEX campaigns.
Initially, the approach was based on ground patterns from the US Department of Agriculture Forest Service’s open-access technical reports, which made it possible to study and model the main characteristics of a ground footprint, namely its length, width and density of deposited product.
The use of numerical simulation as a tool for predicting the drop cloud produced by an aircraft appears to be very attractive for gaining access to all the physical mechanisms involved. However, the computing resources available, even at the biggest French and European computing centers, do not currently allow researchers to describe the entire process from the aircraft to the ground.
The three phases – retardant cloud tearing, atomization and dispersion – explain the various stages that take place between the initial break-up of the product cloud and the formation of droplets that have reached their final size.
An approach developed by PhD candidate Corentin Calbrix in his thesis for Universite de Nimes was limited to describing the fragmentation of the released liquid in a zone close to the aircraft, i.e. 10 metres below the aircraft. Computational fluid dynamics studies of the CL-415 and Dash 8 drops were carried out, showing that fragmentation and dispersion in this zone prefigured ground deposition 50 metres below, which could be deduced by extrapolation of the drop cloud envelop. This approach can now be used to study drops by these aircraft under various operational conditions, particularly in the presence of crosswinds, to help interpret the differences in ground patterns observed during LABEX and provide useful information to optimize forest fire fighting.
Frontal and lateral observation of the release during a LABEX is an essential element in assessing the quality of a release. The eye can identify the quality of product fragmentation and dispersion and anticipate the characteristics of the ground pattern. Packages with a higher concentration of liquid are generally easy to observe and are likely to generate areas of higher concentration on the ground, making the ground pattern less uniform and of poorer quality.
The explanation for this fragmentation mechanism is not yet available: Is it a physical instability intrinsic to fragmentation at this scale, or the memory of a disturbance transmitted to the fluid by the release system? To answer this question, studies are underway at the Institut de Mecanique des Fluides de Toulouse combining wind tunnel experiments and numerical simulation.
A one-tenth scale dropping device has been installed in the 2.4 metre diameter wind tunnel, capable of delivering up to 25 m/s of relative wind. The fragmentation of the liquid column is filmed by a high-speed camera at 2,000 frames per second. The first results of the water release show a specific fragmentation mechanism that cannot be explained by literature results at smaller scales.
A computational fluid dynamics (CFD) code benchmark is underway to challenge various French and American research codes for the study of this instability; these codes must be able to reproduce wind tunnel experiments before the study of fragmentation at aircraft scale can begin.
Ultimately, understanding the origin of the instability and its modes will lead to proposals for better designs for release systems.
The aim of the LABEX research is to better understand and optimize aerial forest fire fighting. It is essential to know the different firefighting missions of aircraft to provide recommendations on the use of the different drop programs available on each aircraft. Climate change leads to changes in fire behavior, and the missions of firefighting aircraft must be adapted to these new phenomena. The tools and experiments described above will be used to improve existing dropping systems, to validate their operational use, and to assist pilots in the understanding of their practice.
By Melanie Wheatley, Colin Mcfayden, Razim Refai, Emily Hope, and Heather Simpson
Suppression or control of wildfires with airtankers is a core strategy for most Canadian provincial and territorial wildfire management agencies. Airtankers include fixed wing and helicopter aircraft that drop water, retardant, or other suppressants onto wildfires.
Across Canada’s vast forests, a variety of airtankers are used, each suited to different fire conditions and landscapes.
Canada’s boreal zone spans more than 550 million hectares – an area larger than the European Union.
On average, about 8,000 wildfires ignite across the country each year, burning about 2.1 million hectares. During extremely active fire seasons – such as 2023 – up to 15 million hectares burned nationwide.
Despite these numbers, the boreal forest is a fire-resilient ecosystem and relies on wildfire for renewal and health. However, when fires threaten valuable forest resources, human lives, or property, wildfire suppression tactics come into play to minimize unwanted impacts.
Skimmer airtankers, which scoop water from lakes, are commonly used in areas with abundant waterbodies such as Eastern Canada. Land-based airtankers, which rely on airport refueling, are more common in regions where lakes are fewer or harder to access, such as some areas in Western Canada and the northern territories.
Some regions use both types of aircraft, combining the advantages of direct suppression with the skimmer airtanker that drops suppressant right on the flames, and indirect suppression, with land-based airtankers that drop suppressant ahead of the fire to create a barrier.
Helicopters equipped with water tanks or buckets are also widely used because they can pick up water from small lakes and rivers and manoeuvre through tough terrain.
Canadian fire management agencies and researchers collaborate on field-based aerial suppression experiments. Andrew Reid, air attack officer (left) is coordinating the tactical plan for suppression on the experiment. Melanie Wheatley, research scientist (right) is communicating the science plan and recording observational data associated with fire behaviour and suppression. Photo courtesy of CIFFC Ontario Ministry of Natural Resources.
Provinces and territories secure and operate their airtanker fleets in different ways. Some regions own and operate their own fleets of fixed-wing airtankers, some contract aircraft (and crew) from specialized suppliers, and others do a mixture of both. Helicopters (rotary-wing airtankers) are generally contracted based on demand. But no agency is left to fend for itself when fire activity exceeds the number of airtankers available.
The Canadian Interagency Forest Fire Centre (CIFFC) helps coordinate the sharing of aircraft and personnel across the country and internationally, ensuring that agencies can share resources and response effectively to wildfire. The record breaking 2023 fire season in Canada presented a historically unprecedented level of resource demand. Canadian agencies received assistance (firefighters and overhead personnel) from 12 countries. Considering climate change, it’s expected that 2023 may not be anomalous, but rather a signal of a new normal.
Leveraging research to improve suppression effectiveness in wildfire operations
Innovation in the aviation space to support wildfire suppression has its history deeply rooted in Canada. The use of airtankers to deliver water – commonly referred to as waterbombing – originated in Canada in the 1940s when pilots in northern Ontario began experimenting by dropping waxed paper bags of water or mounting water drums on aircraft to assist ground crews with suppressing fires. Since then, Canada has continued to innovate and conduct research on airtanker suppression effectiveness. Research in Ontario in the 1990s guided agencies toward an optimal configuration for their airtanker fleets – the type and number of aircraft needed to meet average fire demands.
The complex problem of defining and measuring the effectiveness of airtankers is not straightforward and therefore requires studying the operational use of airtankers in many stages throughout the fire-response process. The current research in Canada is examining the operational use of airtankers including deployment strategies, dispatch prioritization, and understanding and maximizing the effectiveness of airtanker use on fires.
One of the challenges fire managers face is day-basing – a question of where, when, and how many airtankers to pre-position in strategic locations. Researchers in Alberta and Ontario are developing airtanker positioning models to support decision making and resource prioritization.
To lower initial attack response times, a typical approach is to use pre-set rules such as attack radius, response time and fire hazard to identify optimal locations to position airtankers. Studies in British Columbia and Ontario use historical fire and airtanker use data to identify factors that influence airtanker dispatch during initial attack, insights that can be incorporated in optimization simulation models.
Understanding how well airtankers work in real-world operations is critical. In Ontario, researchers have used detailed observations from skimmer airtanker missions recorded from trained air attack officers who are deployed with the airtankers, recording operational mission data including detailed observations of fire behaviour directly observed from the fireline, along with the volume of suppression applied during a skimmer airtanker mission. This data was used to develop statistical models that quantify the ability of CL-415s to reduce fireline intensity on both initial attack and for sustained action missions. These models present the required amount of suppression to reduce fire behaviour to a smouldering state given various levels of presuppression fire behaviour. Importantly, because of the ability of the CL-415 to scoop water from nearby lakes resulting in fast turnaround-times, the findings indicate that in Ontario, the CL-415 airtanker can be effective at higher intensities than previously indicated by current operational suppression effectiveness thresholds used across Canada – an important finding to guide future airtanker use.
Theoretical models, based on what we know about the physical properties of how water and fire interact, have been developed to assess and compare the effectiveness of different skimmer and rotary-wing airtankers used across Canada’s boreal. In 2023, the Ontario Ministry of Natural Resources and Natural Resources Canada published the Reference Guide to the Drop Effectiveness of Skimmer and Rotary Wing Airtankers – a valuable tool for fire management agencies to compare the effectiveness of these different airtankers under varying levels of fire behaviour. Efforts are ongoing to communicate these findings to fire operational personnel.
Because wildfire is a dynamic and complex process, fire management research must go beyond the theoretical science. Field-based research – research on actual wildfires – is considered a gold standard to understanding not only fire behaviour but airtanker suppression effectiveness.
Before examining airtanker suppression on wildfires in the field, an understanding of drop pattern, or footprints of airtankers, is important. Efforts to study and quantify drop patterns, which measure the distribution and depth of water, suppressant, or retardant dropped by airtankers, date back to the 1960s. More recently, Canadian research firm FP Innovations, the Ontario Ministry of Natural Resources, and Natural Resources Canada developed drop patterns for airtankers used across Canada. Various airtanker types – including the Canadair CL-215T, Canadair CL-415, AT-802 Fire Boss, AT-F802F, Sikorsky S-61N, Bell 212, and others – have been tested across open fields, forested, and fuel-treated stands. Using a modified cup-and-grid method, where hundreds of cups are placed on the ground in a large grid to measure the amount of water, suppressant, or retardant collected after each drop, researchers have documented the coverage levels and drop footprints of these aircraft that are commonly used in Canada.
Total cumulative number of aircraft (broken down by skimmer and land-based airtanker) mobilized from 1982 to 2024 by the Canadian Interagency Forest Fire
Centre. Over the last 10 years, an average of 24 skimmer airtankers and four land-based airtankers are mobilized across Canada each year (this does not include
short-term support such as cross-boundary quick-strike coordinated through localized compacts). Plot is re-created from https://www.ciffc.ca/mobilization-stats.
Building on our understanding of airtanker drop footprints, recent field experiments have examined the impact of airtanker suppression action on active wildfires. FPInnovations and Alberta Wildfire have conducted several field-based studies that explore impacts of suppression from both rotary-wing and land-based airtankers. Studies involving helicopter tankers (Sikorsky S-61N) emphasized effectiveness in direct attack applications while those involving land based airtankers (Dash 8-Q400AT) looked at retardant effectiveness in indirect attack applications. Methods used in these studies relied on airborne thermal infrared imagery to collect data from a helicopter (figure 3). These research methods are also being used to explore the effectiveness of suppression activities from night-vision system aided helicopters for actioning fires at night.
In 2024 the Ontario Ministry of Natural Resources, The National Research Council of Canada and Natural Resources Canada initiated field research to test the effectiveness of the CL-415 on wildfires in Canada’s boreal forest. Researchers, paired with fire behaviour experts and operations staff, used an infa-red imaging-equipped helicopter positioned above CL-415 suppression activity to record the associated impact on fire behaviour. This project leverages an experimental design where controlled replicates of airtanker drops are applied in real-world settings to try to limit variability in observations as much as possible. This innovative methodology will process the infa-red imagery to provide detailed estimates of fire spread and fireline intensity, attributes that fire managers commonly used to support their decision making. These field-based studies are necessary to form a baseline scientific understanding of airtanker effectiveness, which will be the foundation of future studies related to optimizing airtanker use in fire management.
There is plenty to learn about how to support the optimization of airtanker use during operations and plan for their long-term role in wildfire management.
The execution and implementation of this research requires close collaboration between those who use the aircraft and those who research them. Canada is fortunate to have strong collaborative relationships between researchers and fire managers, a relationship that is strengthened through networks such as the CIFFC Aviation Working Group, a national group of aviation fire managers who share knowledge on aviation-related challenges in fire management and support innovation to address those challenges.
Thermal imagery is used to study the effectiveness of suppressants on active wildfires.
Agencies play a key role in the research process by identifying research needs, sharing operational data, providing expertise, and supporting field studies that directly measure airtanker performance. Researchers bring the analytical tools and scientific methods to refine and expand our understanding of aerial suppression effectiveness. By combining operational expertise with research, Canada continues to refine its approach to aerial fire fighting, ensuring a safe, effective use of aviation resources to support wildfire management for years to come.
The supply of chemicals for aerial fire suppression across the US has been locked in with the announcement by US Secretary of Agriculture Brooke Rollins that the nation’s Forest Service and Department of Interior’s aerial wildland firefighting force has entered into a new five-year contract.
The new contract is with Perimeter Solutions, a US-based fire supply company, which supplies a range of firefighting chemicals to governments and agencies around the world.
The company, already a long-time supplier of wildfire products to the USDA, CalFire and others, has secured the dominant position as the supplier of fire-retardant in the US for the next five years
Perimeter, according to its website has manufacturing facilities in US, Canada, France, Spain, Germany and Australia. The new contract, however, states that 100 percent of Perimeter’s retardant for federal use will be manufactured in the US.
In a company statement Perimeter claims a “made in America, for America” commitment. “Combined with an increased commitment to sourcing domestic raw materials, the contract reinforces Perimeter’s support for American manufacturing, supply chain diversification, and national resilience. The USDA will receive the lowest pricing Perimeter offers. Together, the benefits of the contract are a result of operational efficiencies and long-term investment in US-based infrastructure by Perimeter Solutions”
In 2024, US federal agencies dropped 48.6 million gallons of fire retardant to fight wildfires. Rollins, in her announcement, boasted that the new contract would save American taxpayers $153 million over the next five years “…including a negotiated direct price reduction and additional cost savings transitioning to full-service bases and powder retardant by 2030.”
“This contract is a tremendous win for America’s taxpayers, our rural communities, and the brave men and women who fight wildfires every day,” Rollins said. “By locking in historic cost savings and bringing every step of the fire-retardant supply chain back to American soil, we are protecting lives, saving communities from destruction, and keeping America safe, strong, and resilient. This agreement proves that when we put America first, we get the best results for our people and our land.”
WildfireToday reached out to the USDA for specifics on where the $153 million in savings comes from, but the agency has not returned our request for comment as of this article’s publication.
Aerial firefighting has become a staple component of South Africa’s approach to combating unwanted wildfires and limiting the devastating impacts of such fires. Its emergence as a critical defence system dates back to the period after the devastating fires in South Africa’s plantation forests in the 1980s. As in other parts of the world, aerial firefighting resources are recognized as necessary measures to combat large fires, complementing the firefighters on the ground.
“The coordination between aerial and ground crews is key to the success of firefighting operations,” said Johan Heine, founder of the Working on Fire programme. The Working on Fire programme is a government funded public employment programme targeting unemployed youth who are trained to serve as certified wildland firefighters; they are deployed at 230 bases across South Africa and abroad in countries such as Canada, Indonesia and Chile.
The introduction of aircraft to combat fires from above significantly improved response times, enabling quicker containment and minimising losses. Aerial fire fighting not only saved the South African commercial forestry industry from collapse but became an integral part of the current wildfire management strategies that protect South Africa’s natural environment.
South Africa typically experiences two fire seasons. The summer fire season is December to April in the southern part of the country, which is a winter rainfall region, and the winter fire season is June to October in the northern and eastern parts of the country, which experience summer rainfall. This seasonal character of the fire season has allowed a relatively limited fleet of aerial resources to cover a country of some 1.2 million square kilometres. However, the impact of climate change has introduced an element of unpredictability as some of the largest recorded fires have occurred in areas out of the normal fire season.
South Africa has three broad fire prone biomes: the savannah bushveld; the grasslands; and a Mediterranean like fynbos area along the southern coasts and mountains and the cultivated commercial plantation forests. The fire risk in South Africa is exacerbated by the prevalence of alien vegetation infestations, such as eucalyptus, wattles, and hakea originating from Australia, and pines from Europe and North America, which propagate wildfires at a fiercer rate and are more demanding on ground water than indigenous vegetation.
In 1981, the commercial forestry industry studied methods employed in North America and initially contracted aerial bombers (Ayers Thrush with 500-gallon hoppers) together with spotter command and control aircraft. Subsequent disaster wildfires in 1985 increased the demand for aerial firefighting resources and gave rise to growth in this aspect of wildland fire management in South Africa. At this point, South Africa also developed a single dispatch centre for coordinating the deployment of both ground and the growing number of aerial resources to wildland fires.
A wide variety of aircraft have been used in firefighting operations in South Africa. The current fleet of aerial firefighting resources includes agricultural application aircraft that are deployed in some areas seasonally to dedicated firefighting operations as part of the Working on Fire programme; these include 10 Thrush 400/500s, five AT802s, four AT502s, 14 Hueys, one Black Hawk, one Bell 212, five Squirrel B3s and some 14-C182, C206 and C210 light aircraft deployed as command and control aircraft.
Initial use of Bell Jet Ranger helicopters equipped with underslung Bambi buckets soon gave way to larger Russian Mi-8s and Kamovs, which arrived in South Africa in 1990 seeking work after the dissolution of the Soviet Union, and later the introduction of the Bell UH-1 Iroquois, commonly known as the Huey, after the original UH-1 designation. The helicopter fleet also serves as essential trooping vehicles for firefighters responding to wildfires in the mountainous and remote areas of South Africa.
The Huey was originally developed and certified by the United States military in 1959 and became the iconic helicopter in the Vietnam War. With its capacity to carry a Bambi bucket holding around 1200 litres of water, the Huey has become a familiar sight in South African skies. Renowned for its reliability and relatively low operating cost, the Huey remains a preferred choice in aerial fire fighting in South Africa. There is also a single version of the Black Hawk helicopter (2500-litre load) that flies alongside a fleet of 14 Hueys and five AS350s (800-litre load) currently operating in South Africa.
The Russian Mi-8 and Kamov helicopters – modified for firefighting purposes – can carry up to 3500 litres and 5000 litres of water respectively. While these aircraft offered powerful firefighting capabilities, they also came with significant operating costs and were ultimately excluded from South African operations by the South African Civil Aviation Authority. The South African Air Force also occasionally provides support with Oryx helicopters during disaster fires.
The fixed wing bomber fleet started with the rotary engine Dromader (2500 litre load), which was replaced with the purpose-built Air Tractor 802, one of the leading single engine airtankers deployed in firefighting operations globally. The AT802 can carry more than 3000 litres of water and chemicals via a computer-controlled water dispensing system.
South Africa has a somewhat unique role for its command-and-control Spotter aircraft, typically high-wing Cessna 182s, 206s or 210s. “Unlike its bird dog counterparts in some other parts of the world, the command-and-control firefighting aircraft in South Africa borrowed from the military forward command and control aircraft which guided its artillery and assumes the role of the air boss over the fire,” said Heine, one of the first spotter pilots employed in South Africa and the founder of Kishugu Aviation.
These aerial command and control aircraft play an essential role in coordinating wildfire suppression efforts and act as the eye in the sky for incident commanders. They provide real-time intelligence and aerial surveillance via a live video link, act as an onsite air traffic control, directing aerial bombing resources making tactical decisions about where to direct water bombing and communicate between ground and air units. Equipped with high-resolution cameras and advanced communication systems, the command-and control aircraft tracks fire behaviour, monitors its spread, and identifies high-risk areas. By maintaining a bird’s-eye view, it enables incident commanders to make informed decisions regarding resource deployment, evacuation strategies, and suppression tactics. Furthermore, it enhances safety by identifying hazards that may not be visible from the ground, such as shifting winds or isolated fire outbreaks, ensuring that firefighting efforts remain efficient and responsive to changing conditions. To do so, these pilots are trained in fire behaviour, wildland firefighting tactics and are in constant communication with all firefighting aircraft, ground teams and the incident commander.
Aerial water bombing in South Africa serves an indispensable role in delivering water to fires in remote and often inaccessible areas. These bombing drops typically consist of water mixed with a two per cent wetting agent to enhance the impact and penetration of water bombing through the vegetation. Water sources for the helicopters vary from ponds and rivers to dams, private swimming pools and sea water for fires close to the coastline. This results in a very rapid turnaround between drops. The fixed wing bombers, however, return to landing strips close to fire prone areas and usually have a five-minute reloading turnaround time.
A Kishugu JV Huey helicopter during the 2016 fire season in South Africa. Photo by Justin Sullivan
As in most countries, South Africa’s aerial firefighting resources, (excluding the occasional use of military helicopters) are privately owned and operated. However, the government-funded Working on Fire programme also includes support for aerial firefighting. The expanded public works programme has grown to employ 5300 firefighters and is supported by Kishugu Aviation’s 10 Hueys, four AT802s, 14 Spotter aircraft and a contracted Black Hawk helicopter.
Other than the national government funded Working on Fire programme, provincial governments, municipalities in fire prone regions, conservation agencies, and fire protection associations enter various contractual arrangements to give them access to the country’s aerial firefighting resources. The Western Cape provincial government has an innovative golden-hour grant, through which it pays for the first hour of aerial resources for any wildland fire in the province, thus facilitating rapid deployment of aerial resources and resulting in many fires being contained within the first hour of detection.
The extent of the wildland fire threat in South Africa outstrips current aerial firefighting resources and sometimes the costs associated with such resources inhibits its use at precisely the time when it could make a significant difference. This is particularly the case as wildland fires, under the influence of climate change, are increasingly extending into the ‘food basket’ grasslands and savannah in South Africa.
The growing impact of climate change will necessitate greater international collaboration in aerial fire fighting. Europe has already led developments in this regard, and sharing of pilots and aircraft is also likely to feature in the future of wildland fire management. It is imperative that forums such as the International Fire Aviation Working Group (IFAWG) be resuscitated across the globe to facilitate meeting this challenge.
Trevor Abrahams is the managing director of the Working on Fire Programme and chairperson of the Kishugu Aviation Division (Pty) Ltd board of directors. He previously established the South African Civil Aviation Authority and served as the Commissioner for Civil Aviation between 1998 and 2003. Abrahams obtained his commercial aircraft and certified flight instructor certificates from the USA Federal Aviation Authority while studying in the United States in the 1980s.
By Matt Plucinski, Nick McCarthy, Owen Price, and Deb Sparkes
There is little quantitative knowledge of, or data describing, how aircraft are used on Australian fires or how effective they are.
Most of the existing operational understanding of suppression effectiveness is anecdotal, highly personal and difficult to compile. Most published data are limited to counts of hours flown, drops made and contracting costs. Inquiries after the devastating 2019-20 Black Summer fire season have made recommendations that research and evaluation into aerial firefighting be undertaken to address this lack of knowledge. The federal government has expressed support for this research and for evidence-based understanding of the capability required for an operationally effective fleet to meet current and future needs.
Matt Plucinski CSIRO, presenting findings from aerial firefighting research at the AFAC25 conference in Perth, Australia, August 2025.
Firefighting aircraft have become more common in Australia over the last few decades.
Current fleets, managed by states, territories and the federal government, comprise of a mix of light and heavy, fixed- and rotary-wing aircraft with a range of capabilities and capacities.
This fleet has evolved over decades through experience, with different aircraft models selected for different environments based on the accessibility of filling points, terrain and obstacles associated with built environments. Firefighting aircraft are more readily deployed to incidents than in the past and are often relocated across state borders in response to fires and anticipation of elevated fire danger conditions and related spikes in fire activity.
Wildfires are managed by state and territory governments in Australia; multiple agencies share responsibility within each state depending on land tenure and location.
Bomber 132, a C130H Hercules, lays a retardant line on the Bullengarook fire in Victoria, Australia, on Dec. 21, 2024. All photos by Wayne Rigg, AFSM, Country Fire Authority.
Most aircraft are contracted from local companies, with larger aircraft bought in from overseas for the high fire danger period. Some agencies have recently begun to purchase aircraft, citing the need for availability during the whole year and a desire for multiple-purpose aircraft.
The unique geographies and arrangements within Australia’s eight state and territory jurisdictions mean firefighting resources are used in a variety of conditions and applications. While aircraft are mostly used to drop suppressants and retardants, they also perform other important roles, such as intelligence gathering, supervision, transport and ignition.
Knowing how aircraft are used during bushfire suppression operations is critical to understanding their effectiveness and will help provide a basis for promoting their effective use. This knowledge would also allow the comparison of usage patterns with intended use. Being able to identify situations in which aircraft are beneficial to suppression operations and those in which they are less so will enable the prioritisation of effective use and improve overall impact and cost efficiency. Restricting the use of aircraft in situations in which they are less likely be effective will also help to alleviate their scarcity and reduce aircrew exposure.
Effective suppression actions lead to desired outcomes for a fire. Successful outcomes can be more readily assessed when compared to explicit pre-defined objectives, which may include containment goals that relate restricting fire extent and impacts within specified time and spatial bounds. Assessing the effectiveness of high-cost resources, such as aircraft, should also consider their benefit in relation to lower-cost alternatives.
The availability of, and difficulty collecting impartial, representative and reliable operational data is a major limitation for bushfire suppression effectiveness research. There are also many diverse and interlinked variables that influence suppression effectiveness that must be considered when evaluating suppression effectiveness, such as those related to fire behaviour, environmental conditions and the application of suppression.
Many projects have investigated aerial suppression in Australia, most notably Project Aquarius, undertaken by the Commonwealth Scientific and Industrial Research Organisation in the 1980s. Project Aquarius established some intensity thresholds for effective drops in some eucalypt forest types; the thresholds were used in an economic model that recommended fire agencies invest in more, smaller, geographically dispersed aircraft than fewer large aircraft that may be slower to respond to distant fires.
Another major project, funded by the Bushfire Cooperative Research Centre in the 2000s, confirmed the significant benefit that aircraft provide during initial attack, particularly for fires that take ground crews longer to access, and fires that occur during conditions conducive to rapid fire growth; the quick travel times for firefighting aircraft can help to minimise the size of fires for incoming ground crews so they have less fire to fight and a greater chance of early containment. The project made some field observations at wildfires and planned experimental fires but noted the significant challenges to the collection of sufficient quantities of data required to support detailed analysis.
In 2023, the Country Fire Authority launched a study to assess aerial firefighting tank systems and suppressants such as water foam and retardant. To date, 57 controlled tests have been undertaken, generating a structured dataset of aircraft and tank system drop patterns to define drop effectiveness in grassland and forest environments.
Some other smaller projects have reaffirmed benefits of the use of aircraft during initial attack while others have provided some case studies of aircraft use.
The findings of aircraft being particularly beneficial during some initial attack situations have been put to good use. Some Australian jurisdictions have developed pre-determined dispatch protocols that automatically send aircraft to first reports of fires above threshold fire danger triggers (before ground-based firefighting appliances request them).
Helitak 367 dropping water on a large spot fire at the Creswick fire, which burned during extreme fire danger conditions in Victoria, Australia, on Dec. 16, 2024. Photo Wayne Rigg, CFA.
From a theoretical economic perspective, the return on investment of aircraft is the greatest when such policy settings are optimised and fires are stopped early. However, the lack of data at a scientific standard to compare pre and post implementation of such policy means policy efficacy is very challenging to study.
Because incipient fires behave differently than steady state fires, and often the best intelligence on fire behaviour comes from aircraft, there is a paradox involved with not ever knowing if such fires needed the support that they received or not. To address this, fire agencies in Victoria are investing in fire reconstructions to collect the standard of data required to answer these questions. The focus for this work is on fires where a) the fire was a close call, meaning the fire was almost or just contained thanks to surge resourcing, and b) where there is sufficient data on fire behaviour to answer the questions.
While the benefits of aircraft during initial attack are well understood and documented, their use and effectiveness during extended attack and on larger fires are not. During initial attack, the objective for most suppression is simply to contain a new fire start as soon as possible, however, objectives can be much more varied for fires that have escaped initial attack efforts. This makes understanding the goals and effectiveness of aircraft use during large fires much more complex and is also likely why the subject has received very little research attention. This is concerning because large fires tend to have significant aircraft deployments that can persist for multiple days.
Aircraft tracking and event records are emerging as an important new data source for analyses of operational responses to fires. Aircraft that are contracted through Australia’s National Aerial Firefighting Centre (NAFC) have been required to provide accurate and timely location and event reporting for a few seasons. This change requires the aircraft to be fitted with position reporting, event-reporting, and messaging equipment and to transmit this data within minutes of collection.
The data collection and transmission operate in the background without influencing operations, thereby providing a true representation of events.
The utility of this data for supporting research on aircraft use and effectiveness has only been explored in a single scoping study that examined data collected during a single season in one state. This study demonstrated that aircraft tracking and event data has great potential for supporting research; it also revealed some issues with completeness, in terms of numbers of aircraft being recorded, and the reliability of some fields, particularly those related to drop volumes and contents.
A further consideration for research using aircraft tracking and event data is that it can only provide some of the information required for studies of firefighting aircraft. Other data sources such as agency records (including fire progression isochrones, situation reports and intelligence logs), interviews with key personnel, and imagery and videography captured during operations, are required to provide critical information on suppression objectives, fire behaviour, environmental conditions and supporting suppression responses.
A new research project funded by Natural Hazards Research Australia and supported by NAFC and state and territory fire agencies will use event reporting data to investigate the application and effectiveness of aerial firefighting. The project, titled Why fly? How do we know that aerial firefighting operations are effective and efficient?, aims to describe the current aircraft use profile and evaluate the effectiveness of aerial fire fighting across Australia using case studies compiled from a range of conditions and locations.
While the Why fly? project is a great step forward to enhance Australia’s understanding of the use and effectiveness of aerial suppression, as a 1.5-year project, it will not be able to address many unresolved fire aviation effectiveness issues facing Australia and intends to make recommendations for further research and analysis.
Important issues, such as line productivity and holding, non-bombing aircraft benefits, cost effectiveness, and the effectiveness of retardants and suppressants are not being investigated in this project or any other current or planned research. For these reasons, continued improvements in data capture, completeness and availability are needed to increase the understanding of how aircraft, and other suppression resources, are applied and what they can and cannot be expected to achieve. These changes, along with further research into the many unresolved fire aviation issues previously listed, will help Australia work toward a safer, more effective and cost-efficient application of aircraft on the country’s fires.
Matt Plucinski is a senior research scientist at CSIRO in Canberra and has more than 20 years bushfire research and firefighting experience. Plucinski has conducted many field and laboratory experiments on topics associated with bushfire behaviour and suppression effectiveness, including evaluations of the effectiveness of large airtankers and assessments of wildfire suppressants and retardants. Plucinski’s research has been used to inform risk management planning, response strategies during bushfires and for fire danger assessment.
Nick McCarthy is a senior research and development officer with Country Fire Authority’s Research and Development team in Victoria, Australia, focusing on suppression effectiveness, future firefighting trends, and field data collection on fire behaviour. McCarthy previously worked as a postdoc with the U.S. Forest Service in Missoula, Montana, and completed a PhD at the University of Queensland in fire-atmosphere interactions.
Owen Price is director of the Centre for Environmental Risk Management of Bushfire at the University of Wollongong and for 18 years has been researching the evidence of impacts of bushfires on biodiversity and buildings and the effectiveness of strategies to reduce bushfire risk; this includes research on prescribed burning, construction standards and suppression with techniques involving spatial, statistical modelling and simulation. Price was born in the United Kingdom and graduated as a biologist before moving to the Northern Territory in 1992, where he worked for 13 years in wildlife research for the National Parks and Wildlife Service. He has authored 140 papers and 50 reports and in 2020 he was joint winner of the Eureka Prize for applied environmental science for analysis supporting the NSW inquiry into the 2019-2020 Black Summer inquiry.
Deb Sparkes is the aviation research and evaluation manager at the National Aerial Firefighting Centre (NAFC), a business unit of AFAC. With extensive experience leading national bushfire management initiatives, Sparkes has played a pivotal role in projects such as the development of the new Australian Fire Danger Ratings System, prescribed burning guidelines, and Spark, Australia’s newest bushfire simulation tool. Driven by a passion for knowledge exchange, Sparkes is committed to fostering collaboration and creating networks that spark innovation and drive progress.
There has been a small but growing body of research within the United States on the use and effectiveness of aviation over the past 15 years; much of this focused on large airtankers.
Studies have focused on understanding where and when aviation drops occur, how fire managers prioritize the use of aviation, optimal fleet design, and how risk management concepts can inform where and when to most effectively apply aviation.
The most expansive research effort to date was the Aerial Firefighting Use and Effectiveness (AFUE) study initiated in 2012 to “systematically document the operational utilization and tactical contribution of aerial firefighting resources that have the ability to deliver water and wildland fire chemicals in support of incident objectives.”
As part of the AFUE study, the research team coordinated with incident commanders to collect data on aviation use on 272 wildfires from 2015 to 2018, including more than 5,000 airtanker retardant drops. The research team recorded the primary suppression objective for each retardant drop based on radio communication, operational briefings, and/or post-hoc conversations with incident management. Drops were then categorized into a variety of different outcomes, including no fire interaction, burned through, halted fire spread, and others. The research team then created performance metrics to measure the likelihood of aviation drops interacting with wildfire and their probability of success.
The AFUE study included observations for a variety of aviation platforms dropping water and retardant.
Halting fire spread and delaying fire spread were the two most common objectives for retardant drops, each representing more than 40 per cent of drop objectives with point protection coming in a distant third at 10 per cent. About one-quarter of all large airtanker (LAT) drops did not interact with the final fire perimeter, demonstrating the use of airtankers for indirect suppression tactics and contingency line development. Not surprisingly, for those drops that interacted with wildfire, the probability of successful drops intended to halt fire spread was lower (55 per cent) than the objective of slowing fire spread (75 per cent) and point protection (87 per cent). Although the AFUE study provided a level of detail regarding drop objectives and relative measures of success, there was an important question unanswered: do these mission objectives truly alter wildfire outcomes during extended attack?
Researchers at Colorado State University are engaged in a study to provide formal calculations on the effectiveness of large airtanker retardant drops at altering wildfire growth. The researchers use data provided by units mounted inside LATs that record the exact locations and times of retardant drops, along with information on the daily growth of wildfires from 2017 to 2019, to evaluate fire characteristics before and after the wildfire passes over the retardant line. The researchers evaluate the change in wildfire characteristics as the fire moves through a swath of land that is split by the retardant line. However, a critical piece of information to understand the effectiveness of LAT suppression at the drop level is a comparison with areas unaffected by retardant.
To ensure accurate comparisons, the researchers measure wildfire outcomes in adjacent areas with similar vegetation and topography. The key difference? These areas lack retardant lines, serving as a control, thus creating what is known as a natural experiment. The difference in the change in wildfire outcomes as the fire moves through these two swaths of land provides statistics for the effectiveness of LAT retardant drops.
Aviation drops relative to daily fire progression and populated areas on the Alexander Mountain Fire in Colorado in 2024. Heavy retardant use during the first several days of the event were unsuccessful in stopping the fire, requiring operations to fall back to more favorable locations near populated areas. Graphic by Jim Riddering.An overlay of airtanker drop locations with the Potential Control Locations. Fires have a high likelihood of stopping in areas with cool colors (blue and green) and low likelihood in hotter colors (red and orange). The image shows drops on the Alexander Mountain Fire in the Pike San Isabel National Forest in Colorado in 2024. Graphic by Jim Riddering.
The researchers evaluated the effectiveness of LATs at halting wildfire progression, reducing the intensity, and delaying the spread of wildfire; they found that LATs are effective at altering wildfire outcomes in all three ways.
Wildfire is 8.4 per cent less likely to spread into land that is protected with an LAT drop compared to land that is not buffered by retardant.
Similarly, the intensity of fire (measured by the gridded Monitoring Trends in Burn Severity layer) is 7.5 per cent lower for land protected by a retardant line.
Land protected by retardant takes four to five hours longer to burn than unprotected areas, giving crews crucial time to respond.
These findings reveal the tangible impact of LAT drops on wildfire behavior, offering key insights for suppression strategies.
These statistics aggregate the effectiveness of retardant drops across a variety of landscape and weather conditions. However, the Colorado State researchers have found that LATs are more effective across all three dimensions when dropping on land covered with shrub vegetation, compared to areas dominated by grass or trees. They have also found that air tankers can delay the spread of wildfire by more than 30 hours when used in conjunction with other types of suppression, and that tankers classified as very large airtankers, or VLATs, based on larger tanks for holding retardant, can reduce the likelihood of fire spreading by roughly 12 per cent relative to land not protected by any retardant drops. This research also provides assessment of the influence of topography and general weather conditions on drop line effectiveness.
Understanding the effectiveness of large airtanker drops is a crucial step in refining wildfire suppression strategies, but translating research results into actionable feedback for incident management teams remains a challenge.
Developing processes to review past actions and provide near real-time information to the field is essential for improving future wildfire responses and maximizing the effectiveness of airtanker use.
As such, researchers and fire managers have been using additional telemetry units (ATUs) to track various metrics associated with air tanker drops. ATUs are mounted on all federally contracted airtankers (and some single engine airtankers – SEATs). ATUs are GPS-enabled devices that track parameters such as aircraft location, time, heading, altitude, and most importantly, tanker door open and close events.
ATU data have been used since 2017 to calculate air tanker drop locations and associate various analytics with those drops. These original aviation use summaries (AUS) were manually produced and provided to fire managers through the US Forest Service’s Risk Management Assistance (RMA) dashboard to help inform how fire chemical and water were being applied to the landscape.
Additionally, the AUS process can be used as a powerful after-action review of the effectiveness of aviation drops in supporting suppression actions. Original metrics associated with the AUS reports focused on analyzing time of day, fuel types, and slope classes where the drops were occurring. Subsequent AUS development used the rise of integrated metrics such as suppression difficulty index (SDI) and potential control locations (PCL) within the RMA dashboard to provide additional context for managers to evaluate the use of air tanker drops on incident strategy and tactics.
More recently, US Forest Service personnel have worked to automate the processing of ATU data to expedite the production and distribution of airtanker drop information and associated analytics. Daily processing starts by creating lines from ATU GPS point data for door open and door close events. These derived drop lines are then extended to account for forward momentum of the fire chemical or water. Next, drop lines are buffered and values for SDI, PCL, slope, elevation (of the line), and majority fuel model are extracted for the buffer, and appended back to each drop line feature class (Figure 1). A significant amount of processing time is devoted to quality assurance to remove redundant or bad data points and ensure the creation of logical drop lines. Problematic lines are flagged as possible false positives but retained in the database. Other attributes added include split drop information (where a tanker will split the load and do multiple drops in one flight), the calculation of various time parameters, and incident name association. The final step updates an ArcGIS Online (AGOL) Feature Service. The feature service feeds an AGOL dashboard that is available to credentialed managers and users. Work continues to improve estimation of gallons dropped and tracking costs associated with flights.
Through the automated processing and near-real time distribution, users such as incident management team members, aviation officers, and coordination center managers are better able to monitor drop locations (including areas of misapplication), assess the use of air tanker resources on their incident, and build knowledge using derived analytics to help them evaluate the effectiveness of air tanker resources.
This work highlights the importance of integrating research findings with managerial experience to determine effective resource use. Dan Dallas, an incident commander with the US Forest Service in Colorado and early adopter of the AUS system explained the value.
“The AUS provides us the ability to examine recent drops in near real time on fires we manage giving us the information necessary to identify where and when aviation could best support suppression actions. Using the AUS to examine our management of past events allowed us the opportunity to think more clearly about how aviation can best support our incident strategy. This has allowed us to clearly articulate our strategy in aviation use to the hosting unit and our field-going personnel. We firmly believe the use of AUS has significantly improved the effectiveness and efficiency of our suppression actions and overall fire strategy.”
Aerial drops are probably the most iconic and visible activities in wildfire suppression and often a critical component to initial attack and large fire suppression strategies. The effectiveness and efficiency of wildfire suppression actions writ large is poorly understood, and we largely rely on the experiences of incident management team members and field-going firefighters to determine what resources are needed and where they should engage.
Aviation is but one component of wildfire suppression and the coordination of the broad array of ground and aerial resources is a highly complex process.
The AFUE study provides an indication of the type of objectives and conditions of effectiveness but did not uncover how objectives contribute to overall fire suppression outcomes.
Given the costs of wildfire suppression, exposure of ground and aviation personnel, and the impacts to natural and developed resources, improving the effectiveness and efficiency of wildfire management is essential and understanding aviation’s role will be critical to that effort. Progress will be contingent on the ability for researchers and managers to work together to foster more safe, effective, and efficient solutions.
Dave Calkin is a supervisory research forester with the US Forest Service, Rocky Mountain Research Station in Missoula, Montanna. Calkin’s work is designed to improve risk-informed decision making through innovative science development, application, and delivery incorporating economics with risk and decision sciences. Calkin’s research interests include risk assessment, collaborative wildfire mitigation and response planning, suppression effectiveness, and risk informed decision making. Calkin developed and leads the Wildfire Risk Management Science (WRMS) team within the US Forest Service Rocky Mountain Research Station.
Cal Bryan is a post-doctoral researcher in the Agricultural & Natural Resource Economics department at Colorado State University, interested in researching methods to optimize operational resources for fighting large-scale wildfires. Bryan holds a bachelor’s degree in bioenvironmental sciences from Texas A&M University, a master’s degree in economics from San Diego State University, and a PhD from Colorado State in agricultural and natural resource economics. Bryan’s PhD dissertation, titled Evaluating the Efficiency, Equity, and Effectiveness of Wildfire Suppression Strategy Using the Microeconomic Toolkit, focuses on determining patterns in large airtanker use across wildfires in the United States and their effectiveness at altering wildfire outcomes. Before starting graduate school, Bryan spent several years working seasonally for the U.S. Forest Service in various roles, including trail crew supervisor, interpretive ranger, and type-II wildland firefighter.
Jim Riddering is an aviation analyst with the Strategic Analytics Branch of the U.S. Forest Service Office of Fire and Aviation Management. Riddering’s responsibilities include managing the Additional Telemetry Unit (ATU) program, developing data processing streams, and providing analysis of aircraft use. Riddering holds a PhD in forestry from the University of Montana and has more than 20 years of wildland fire experience, including time on hotshot and engine crews. Riddering is a qualified Aerial Observer (AOBS), holds a private pilot’s license (SEL), and is working on completing his Long-term Analyst (LTAN)
