Protecting property at the wildland-urban interface (WUI) is a vital focus for helicopters in firefighting. Buckets and tanks play varying roles in these challenging operations, with a range of technological developments underway to enhance performance in the coming years.
Mike Sagely, a retired senior pilot with the Los Angeles County Fire Department (LACoFD), said the agency uses metal Kawak tanks on its Firehawk platforms. He pointed to several advantages of today’s systems, notably the increased freedom to operate over urban or built-up areas. Modern tanks can also adjust coverage levels through computer-controlled drops.
“You can tailor the amount of water you drop, and precision in water dropping is obviously important,” he said.
Tanks are more commonly deployed than buckets in Southern California, Sagely said, because buckets may need to be jettisoned, which can pose problems in urban areas. However, long-line buckets still offer advantages in a range of situations, particularly in forested terrain. They also allow operators to be highly precise in “spot drops,” he added.
Regardless of the system used, the WUI presents a unique set of challenges, Sagely explained. Homes are often situated in remote areas such as hills and canyons, surrounded by fuel sources like trees or dry grass.
Sagely said he has often faced smaller fires burning right next to homes. When flames move along the interface line, firefighters must contend with a variety of “emerging, immediate threats” that demand individual responses.
“You might have a tactic or a strategy for the fire overall, but now you’re faced with something that has to happen right now — an emerging threat that’s about to impact a home,” he said.
Such a threat might be identified by an aircraft conducting a water drop or by another form of aerial supervision, which then directs resources as appropriate to that house or line of houses — or to a nearby tree, for instance. This presents a key consideration: how to accurately drop water in close proximity to a home while minimizing any potential damage caused by the drop itself.
This brings in factors such as the helicopter’s approach direction, altitude, and speed. Other challenges also arise in the WUI, Sagely said. Power lines, for example, often run to homes in these areas and can blend in with trees or other sources of fuel.
“It’s important to understand what your water effect is going to have — not only on the fire, but also whether it might cause any additional issues.”
Firefighters also consider the specific terrain involved in WUI operations. In Southern
California, for example, there are large numbers of palm trees. During fires, palm fronds can “become their own fire candles — if it’s windy and they start blowing around, they keep starting other fires, potentially impacting other homes.”
Sagely said there have been significant technological advancements over his 16 years as senior pilot at LACoFD. One area of progress is the growing emphasis on collecting data from water drops — recording how much water is released and using GPS tracking to more precisely determine where the drops occur.
The ability to conduct computer-controlled drops is also valuable, particularly when determining how much water to release. Grass, for instance, doesn’t require the same coverage level as trees to effectively extinguish flames, meaning operators can select a lower setting on the tank, increase speed, “and put out maybe 150 yards of fire on a fire line in grass with just one [aerial] drop.”
On other occasions, when there’s a high concentration of fuel in a small area, the drop needs to be much heavier, he said.
“It’s shocking sometimes — it’s almost like somebody’s down there restarting the fire,” Sagely said. “So having that coverage level with very good impact force and penetrating force is very important, and there are systems that make a real difference in how efficient that is.”
Kawak Aviation
Kawak Aviation produces the most widely used belly tank and retractable snorkel system for the Firehawk. In addition to LACoFD, the 1,000-US gallon (3,785-liter) tank system is employed by several agencies, including Cal Fire, Ventura Fire Department, San Diego City Fire, and others. The company also manufactures a 2,500-US gal (9,464-L) tank system for the Boeing CH-47D Chinook Type 1 helicopter.
In recent years, Kawak has introduced the Cascade Firefighting Bucket, available in
sizes ranging from 260 US gal to 1,000 US gal (984 L to 3,785 L), with an extra-large 2,600-US gal (9,842-L) variant. The system features a power-fill pump for rapid shallow fills and a collapsible design for easier ground handling, said Andy Mills, vice president of business development.
There are currently 35 Kawak Type 1 tank systems in operation on firefighting helicopters, Mills added, along with more than 60 Cascade buckets. He pointed to the January 2025 Pacific Palisades and Altadena fires in Southern California as an example, when 14 helicopters were equipped with Kawak tank systems and two with 900-US gal (3,407-L) Cascade buckets, collectively flying 1,450 water loads over four days.
The precision of the drop pattern is critical in WUI operations, Mills noted, with Kawak Aviation tank systems engineered to deliver a high-flow, concentrated pattern for greater accuracy and effectiveness. The Firehawk systems also feature a retractable snorkel, ensuring nothing hangs below the aircraft and allowing for maximum cruise speed, he added.
Kawak Aviation continues to advance its technology, including the development of a second-generation CH-47D tank system with a stowable rotating snorkel, as well as refinements to its bucket design based on operator feedback.
“We will be offering new tank systems for some of the next-generation, medium-class helicopters that are now being bought for use by agencies in the WUI,” he added.
Mills added that recent fire seasons have influenced the company’s production planning — particularly the need for improved coordination with third-party vendors to align build schedules with fire seasons that are starting earlier each year.
“If we agree to build a firefighting system for someone, it has to be delivered in time for fire season,” he said. “We can’t simply put production off until later. We have to start pre-planning and material ordering earlier in the cycle than we used to.”
DART Aerospace
DART Aerospace manufactures both tank and bucket systems for aerial firefighting. One of its best-known products is the Bambi Bucket, which provides flexibility and rapid deployment for wildland and remote-area missions, said Benjamin Murat-Prats, vice president of sales and marketing. He noted that the Bambi Bucket is engineered for accurate, effective drops even in difficult terrain, with features such as precision drop control, power-fill systems, and variable flow valves.
The company’s new Fire Attack System is a tank developed in partnership with United Rotorcraft for the Airbus Super Puma helicopter family. It consists of a fixed, externally mounted belly tank with a capacity of 4,000 L (1,057 US gal) and controls integrated into the cockpit.
“Each fire season, our products are deployed around the world to support aerial firefighting operations,” Murat-Prats said. “Most recently, during the intense fires that impacted California at the beginning of 2025, both the Bambi Bucket and Fire Attack Systems played key roles in helping operators protect communities in extremely challenging conditions.”
Water access can be a challenge in WUI environments, Murat-Prats noted, pointing to the Bambi Bucket’s Shallow-Dip, Power-Fill, and Fireflex Pumpkin tanks — all designed to enable helicopters to quickly and safely fill from nontraditional water sources.
Longer and more intense fire seasons have driven growing demand for both Bambi Buckets and Fire Attack Systems, he said. The company has “adapted by increasing production capacity, improving inventory, and working closely with operators.”
DART is also continuing to innovate across both product lines, Murat-Prats added. The Bambi Bucket is being enhanced with smarter drop systems, telemetry integration, and lighter, more durable materials to support faster turnaround times and improved pilot feedback.
“For our Fire Attack Systems, we’re exploring greater automation, expanded aircraft certifications, and integrated flight data tools — allowing for safer, more efficient missions in regulated or high-risk environments, including night operations,” he said.
Helitak
Helitak Fire Fighting Equipment manufactures both externally mounted fire suppression tanks and external water buckets. The company offers nine tank models ranging from 1,000 to 11,000 L (264 to 2,906 US gal) in capacity. The lineup includes the FT1300–FT1400 for light helicopters such as the Airbus AS350/H125, H130, and H135; the FT1800–FT2400 for medium-lift helicopters like the Leonardo AW139; and the FT11K for large aircraft like the CH-47 Chinook.
The company’s Aerial Strike range of water buckets can serve as either an alternative or a complementary system to its tanks, said Nicholas Noorman, business development manager at Helitak. These buckets are compatible with Helitak’s drop controller/fire tank controller and other existing components, and include features such as multi-stage drop capability and rapid-fill functionality.
Additional innovations across the range include shallow-fill pumps and the Fire Tank Control system, which enables more precise control of water or retardant release — particularly valuable in the WUI to avoid collateral damage to homes and other structures, Noorman noted.
He pointed to other advances as well, including faster fill and refill cycles for quicker response times, increasingly precise drops, and improved aircraft safety and maneuverability through lighter tank and bucket designs — all hallmarks of recent innovation.
Worsening fire seasons have brought both positive and negative effects, Noorman said. On the positive side, “the demand for aerial firefighting-equipped aircraft has never been greater,” reflecting a major shift in how wildfires are managed.
However, the growing demand has also created logistical and regulatory challenges when operating across different jurisdictions, as well as increased maintenance and support requirements, he noted.
Noorman said Helitak continues to refine the design of its systems to maximize their ability to deliver water to the fire ground. He expects to see continued evolution in the platforms used to deliver that water — developments that will, in turn, influence specialist providers like Helitak.
“We are already working with drone platforms to combat wildfires — this will remove the risk of putting pilots and firefighters in harm’s way,” he said. “A lot of effort is also going into the ability to predict how fire will react and to better manage the landscape as a preventive measure.”
Perimeter Solutions
Retardants play a vital role in aerial firefighting — including at the WUI — and for specialist provider Perimeter Solutions, a preventative approach is key.
The company’s primary helicopter product is PHOS-CHEK 259-Fx, the only magnesium corrosion-approved long-term fire retardant designed for use in fixed-tank helicopters.
Perimeter also emphasizes the importance of ground-applied long-term retardant, said Shannon Horn, chief operating officer at Perimeter Solutions. These applications can support aerial operations as a preventative treatment ahead of fire season or be deployed reactively during active incidents, he noted.
For instance, during the recent Garnet Fire in California, Perimeter’s long-term retardant was used both in the air and on the ground, Horn said. Five trucks applied retardant along evacuation routes and established control lines to support burnout operations, while aerial drops reinforced containment efforts.
“The trade-off is that while aerial drops can cover larger areas quickly, ground applications provide surgical precision — both during incidents and ahead of fire season, if communities are willing to invest in pretreatments,” Horn said.
He noted that the combined strategy used during the Garnet Fire slowed the blaze enough to allow safe evacuations and protect structures, providing added safety for both helicopter and ground crews.
“Incidents like this demonstrate how critical tactical ground application can be during fires and highlight why investing in pre-season treatments can give communities an even greater head start.”
Horn said the company expects WUI firefighting to increasingly integrate ground and aerial retardant applications. “Together, these tools provide the layered flexibility agencies need to respond under any conditions.”