As the frequency and intensity of wildfires continue to rise, so too have the tactics used to combat them evolved. Here we take a look at the latest developments alongside the emerging technologies and equipment.
This article was featured in the April/May 2024 edition of RotorHub International, and all information is correct at the time of posting. To receive articles like this directly to your inbox or address, apply for your complimentary subscription today.
The impact of climate change and increasing demand for aerial firefighting
It is no longer a debate, but while there are those who can and do argue the reasons for it, climate change is a reality.
One of the direct results of the change is the increase in both the frequency and intensity of wildfires.
Even while some parts of the world have “enjoyed” milder fire seasons of late – both California and Australia spring to mind – in others, Canada and much of southern Europe, last year was a record breaker.
As one experienced aerial firefighting pilot said recently: “The kind of fires that used to be legendary when I first started in aerial firefighting – in fact so legendary that as a new guy you thought they might be like fishermen’s tales – are now commonplace. You can’t get away from that.”
Additionally, as weather patterns evolve, additional strain is being put on the resources that are available to fight more and bigger fires.
Not only are seasons becoming busier, but the fire season in each hemisphere has likewise extended.
This means that aircraft and teams that could be expected to “winter” in the southern hemisphere either can’t stay for the whole season or are late for the start of the next season in the other hemisphere.
Since a small fire is easier to deal with than a large one, the question is how to respond to a fire’s outbreak as quickly as possible. One possible solution that has been effectively employed is forward deployment.
A high-profile example, and covered in more detail elsewhere in this edition, is Cal Fire, which deploys its fleet and associated assets across the state to ensure a rapid response.
And yet there are some surprising holes in the net, with Texas recently suffering its largest ever wildfire.
Not only was the Smokehouse Creek Fire a demonstration of the ever-extending fire season, it also revealed the gaps in Texas’s wildfire fighting capabilities.
Surprisingly, much of the state’s aerial firefighting capability is positioned in the San Antonio area, several hours’ flying time from the panhandle in the north of the state where Smokehouse raged and 1,654 square miles burned.
A case can be made for Texas to consider how best it might deal with future fires – and that might look a lot like Cal Fire.
Division of labour: evolving firebreak tactics
Traditionally, the division of tasks between fixed and rotary assets have seen the fixed wing aircraft take care of the retardant role while helicopters have taken on the direct attack tasking.
Broadly speaking, retardants are used to form firebreaks – usually to contain fires, although they are often employed to provide escape routes for firefighters on the ground who may be outflanked as the result of a sudden wind shift.
Critical to creating an effective firebreak with retardant is a continuity of coating along a particular line.
Clearly, then, the larger the load an aircraft has, the fewer drops are required to create the break and thus the greater the likelihood of a contiguous line.
Meanwhile, when water is being used to suppress fires, the ability of helicopters to refill tanks from any convenient body of water means that they can be relied upon for the direct attack tasking.
Add to that the multi-role element of the equation. Helicopters can be used to insert ground firefighting teams and then within moments of drop-off can be in direct attack mode.
And so it has been since the addition of helicopters to the aerial firefighting armoury, though it remains the case that a good deal of the direct attack capability has come from external load buckets as a delivery system.
SEI’s Bambi Bucket, which for the last 40 years has dominated the market to the extent that its brand name has, like Hoover for vacuum cleaners, become a byword for long line external delivery systems.
SEI offers a range of buckets with capacities from 270 litres all the way up to the imaginatively named Torrentula system, which has a capacity of up to 9,800 litres.
New platform: the importance of forward deployment in fire suppression
Western States Fire has carried out a number of demonstration test of its SKHI-ex Aerial Fire Suppression Solution.
At the larger Type 1 end of the scale – aircraft with a tank capacity of greater than 2,650 litres (750 US gallons) – the trend has been a migration to tank systems that, while externally mounted in order to preserve the multi-role utility capability, are fixed to the airframe.
Australia’s Helitak systems have created a range of tanks for not only the CH-47, with a capacity of 11,000 litres per lift, but also in the Type 1 class supply the tankage for the Super Puma-based Firecats that have the ability to deliver up to 4,250 litres a load on to the fire ground.
Then there is the UH-60 tank, which has a slightly higher maximum load of 4,500 litres.
The nifty thing about the Helitak system is that it uses the existing hard points on the airframe, which means that aside from negating the need for modifications to the airframe and all that entails, when the time comes to divest the airframe, it will remain a stock example.
A new entrant to the Type 1 mix was announced at the end of February, when Coulson and Kawak announced their intention to develop a UH-60/S-70 based firefighting platform featuring an integral external tank. Coulson Aviation’s President and COO, Britt Coulson, explained the thinking behind the development as follows.
“The original firefighting Blackhawk was first brought to market more than 25 years ago, and there has been no innovation or significant improvement on the platform since,” he said.
“By leveraging our design, manufacturing, installation and operating experience, we’ve made several significant improvements to not only boost the aircraft’s capabilities and safety but also provide access to the platform within various budgets. Partnering with Kawak is a big piece of that work.”
With increasing numbers of larger capacity in rotary solutions, using the aircraft for retardant delivery as well as direct attack is becoming a feasible solution – provided that retardant can be brought forward close enough to the fire ground so that the flexibility of helicopters can be maximised.
This is something that fire retardant suppliers Perimeter Solutions have thought long and hard about. As a result, as part of its offering the company has an extensive forward deployment capability, which means that assets are sited in expected zones ready for positioning into tactical zones as required.
As part of this capability, open top tanks are used so that the same snorkel/lift pump system used in water direct attack is used for refilling.
“The original firefighting Blackhawk was first brought to market more than 25 years ago, and there has been no innovation or significant improvement on the platform since,”
Britt Coulson, President and COO, Coulson Aviation
In the mix: Changing the chemistry of liquid retardants
According to Jeff Emery, President of Global Fire Safety at Perimeter Solutions, the deployment to forward operating positions can be completed within a few hours.
Even though deployment is rapid, it will mean nothing if the retardant put on the ground is less than effective.
With this in mind, the company has carried out a rolling programme of development of the chemistry of its products to ensure that its phosphate-based retardants deliver higher performance.
Perimeter Solutions has recently developed PHOS-CHECK LCE-2-Fx – which is a rather long name for a product that combines the mixing and handling advantages of a liquid retardant with the improved drift, dispersion, and evaporation characteristics of a thickened product.
Which, Emery notes, makes it more effective for use on ground vegetation.
There are also those who will advance the idea that evolution in product development, while laudable, also risks missing the opportunity for a step change in fire suppression capability.
Leading that chorus is Australia’s BlazeTamer, which argues that its BLAZETAMER380 offers a far more effective solution for direct attack of fires compared with pure water.
The company notes that when combined with water at its optimum ratio range (0.2 to 0.65 per cent) the resulting mix weighs in the order of 8.3 lb per US gallon (3.67 kg/USG), and so is actually lighter than pure water – or around a pound per US gallon less than water/retardant mix. Yet this results in a fluid that is up to three times more effective in absorbing energy from fire compared with pure water.
According to BlazeTamer’s North America representative, Bill Schuster, the critical advantage comes in the ability to create the mixture on aircraft.
This, he says, “means the flexibility of loading from lakes, rivers or other water sources is an option”.
Schuster also stresses that for all its advantages and cost (around a tenth that of retardant), the product is emphatically not a retardant and is only a direct attack enhancer.
Mounting up: the future of aerial firefighting technologies
On the retardant side of the equation, Western States Fire points out that apart from adjustments to the chemistry of
retardants, not much else has changed in the last 80 years.
This is something the company says it plans to address with its SKHI-EX suppression system, which is designed to be fitted to Type 1 helicopters.
Using an expanding foam retardant allows each aircraft to lay down 35 miles of retardant per day compared with the average of seven miles a day laid down by a C-130 air tanker with a 4,000 USG load capability.
For now, the designs are optimised for CH-47s and S-64s. In the latter case, the foam generator unit will be mounted in the typical tank position, while for the Chinook the foam generator is internally mounted – with the hose trailing from the cargo hook hatch in the aircraft belly.
While the programme remains in the development phase, patents have been filed with the US patent office and the company has carried out a number of demonstration tests.
According to founder and CEO Larry Sukay, the system is expected to start entering service with the suspended units on S-64s in 2025, with FAA certification of the full kit expected the following year.
Clearly then, the aerial firefighting landscape is continuing to adapt to the ever-accelerating change in the firefighting landscape.
The question is, while operators and technology developers continue to come up with both new procedures and technology to improve the effectiveness of their responses, will funding be able to keep up with the demands of the mission?
As one speaker at Aerial Firefighting North America reminded delegates: “We are competing with a lot of other equally worthy disaster responders and have to keep that in mind. We’re important, but not special.”
We hope you enjoyed our firefighting tactics feature. You may find these new stories interesting:
Helitak granted FAA STC for FT11K external tank
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