Australia is the driest inhabited continent on earth. The country experiences ferocious wildfires in summer when temperatures often exceed 40°C / 104°F. During the Black Summer fires that started in June 2019 and burned until the following May, more than 18 million hectares were reduced to ashes, 33 people perished as a direct result and 450 more died from the effects of smoke inhalation. The Royal Commission into National Natural Disaster Arrangements was announced in February 2020 and when presented to the Australian Parliament on 30 October 2020 it came with some 80 recommendations – from trialling aerial firefighting at night, to developing a ‘sovereign’ aerial firefighting capability. Since this time, Australia has seen significant growth in its aerial firefighting fleet with the addition of a permanent, more capable Australian based rotary- and fixed-wing fleet.

Investment into aerial fire assets

As a result of continuing improvements and implementation of these recommendations the New South Wales (NSW) State Government has pledged more than AUD$450 million. This includes a $268.2 million funding package consisting of $17.2 million to operationalise two sovereign Black Hawk helicopters to replace existing aircraft, $5.2 million to increase remotely piloted aircraft capabilities, and $10.6 million to assist with the implementation of the new National Fire Danger Rating System.

According to the National Aerial Firefighting Centre (NAFC), the national department responsible for providing a cooperative arrangement for the provision of aerial firefighting resources, there are currently approximately 150 aircraft contracted by the NAFC on behalf of state and territory governments, which is supplemented by additional state-owned and contracted aircraft. In total, there are more than 500 aircraft provided by over 150 operators available across the country for aerial firefighting.

The start of the 2021 fire season saw the first ever sovereign Boeing 737 Fireliner™ Very Large Air Tanker (VLAT) locally contracted to the Australian Federal Government in partnership with the NAFC and Coulson Aviation Australia. A converted B737-300, ‘Tanker 137’ (yet to be named locally via a naming competition) is no stranger to the Australian skyline, having operated in the country since 2018 and is capable of dropping 4,000 US gallons (15,200 litres) of water or retardant, up to a rate of 3,000 US gallons (11,300 litres) a second.

At the time of writing, ‘Tanker 137’ is based out of Busselton in Western Australia supporting significant fire activity and is available nationally as and when required.

The season has also seen the introduction of two of the world’s largest firebombing helicopters, the Boeing CH-47D Chinook. Also operated by Coulson Aviation Australia, in partnership with NAFC, the Chinook is capable of carrying up to 3,000 US gallons (11,300 litres) of retardant or water and is a night fire-suppression and night vision goggle-capable aircraft. One will be based out of Victoria and the other in New South Wales.

In addition to the 737 Fireliner™ and two CH-47D Chinooks, the NAFC has contracted five Sikorsky UH-60 Black Hawk helicopters fitted with Helitak FT4500 Black Hawk Fire Suppression Tanks (currently the only FAA-certified underbelly fire suppression tank for the Black Hawk) capable of carrying up to 1,060 US gallons (4,000 litres) of retardant or water with a 35-second snorkel re-fill time.

The Black Hawk, like the Fireliner™ and the Chinook, is no stranger to operating down under, however this is the first time they will be contracted for the entire season rather than on the usual ‘call when needed’ basis. Two Black Hawks are based out of Western Australia and operated by United Aero Helicopters, another two in South Australia operated by Aerotech, and the other in New South Wales by Touchdown Helicopters.

Texas-based Air Tractor is a leading manufacturer of agricultural aircraft, which are also very effective for firefighting missions, such as spraying retardants in challenging terrains, making them popular dual role aircraft in fire-prone Australia.

Stephen Holding, the General Manager of Field Air, an Australian dealer and operator of the aircraft, says the Air Tractor is generally used on the continent for agricultural applications, like spreading fertilizer on large cropping areas, but this capability also makes it an ideal choice as a single-engine air tanker for firefighting.

The Air Tractor AT-802 also has the distinction of using the most powerful variant of the Pratt & Whitney Canada PT6A turboprop, the PT6A-67F, which has 1,700 shaft horsepower.

The Air Tractor has a computerized firedoor, allowing the pilot to select how much retardant to drop and how big an area to cover, an extremely important capability for aerial firefighting

Holding reveals that because the Air Tractor needs to carry a huge load, it has a high power-to-weight ratio. The aircraft, for example, has a maximum take-off weight of 16,000lb (7,257kg). “An AT-802 can carry approximately 800 US gallons (3,000 litres) of fire retardant,” he adds.

When retardant is dropped on vegetation, it can last for a couple of weeks. It dries on the herbage, forming a layer that retards the progress of a fire, says Holding, adding that retardant is more effective than foam concentrate or water gel, some of the other liquids that Air Tractors use to combat fires.

Holding comments: “Air Tractors have two main firefighting roles. The first is fighting the fires directly on the frontline. The latter role is known as ‘retardant line-building’, where the Air Tractors work ahead of the fire to build up defensive lines and fire suppressants around strategic assets.”

The Air Tractor has a computerized firedoor, allowing the pilot to select how much retardant to drop and how big an area to cover, an extremely important capability for aerial firefighting.

Another advantage of an Air Tractor is its deployment speed and adaptability, Holding notes: “Compared to large air tankers, the smaller-sized Air Tractor can be deployed faster. Since it is originally an agricultural aircraft, Air Tractors can operate across various types of terrain, such as grass, field, gravel and fly from air strips and runways of around 2,600ft (800m) length, which makes it perfect for manoeuvring at the scene of a fire.”

The largest model of Air Tractor is the AT-802, of which there are approximately 100 in Australia, and the variant designed for firefighting is the 802AF or 802F. The ‘F’ variant also includes an amphibious version; the AT-802F Fire Boss is fitted with Wipaire floats. There are 12 Fire Boss amphibious aircraft in Australia.

Says Holding: “The AT-802’s wing tanks can hold up to a maximum of 390 US gallons (1,476 litres) of jet fuel and burns between 80–92 US gallons (300–350 litres) per hour depending on various factors like altitude and speed.”

Holding asserts that due to its heritage as an agricultural aircraft, Air Tractor is designed to work in hot, dusty and tough environments; but the aircraft also needs a resilient engine to back it up, which is where Pratt & Whitney Canada’s PT6A-67AG and F engine comes into play. About half the AT-802s in Australia are fitted with the AG engine and the rest with the F, he says. “Many firefighting operators these days with the AG-equipped AT-802 have started to upgrade this engine to the PT6A-67F variant, which has more power and more load carrying capacity.”

The AT-802F reloads in 5 minutes and ferries at 175 kts. It is often the first and only airplane sent to early-stage fire

Jim Hirsch, President of Air Tractor, Inc., explained what makes Air Tractors so well suited to the unique challenges of operating in the Australian climate and geography: “Air Tractor airplanes are up for the challenge posed by Australia’s rugged terrain and climate. The AT-802 routinely flies from unimproved airstrips at locales around the world. Its PT6A-67AG turboprop engine performs quite well in hot, high density altitude conditions.”

And when it comes to being part of the aerial firefighting team, the speed of reload and attack means it can be first on scene. Hirsch explained: “The AT-802F reloads in 5 minutes and ferries at 175 kts. It is often the first and only airplane sent to early-stage fires. On bigger fires, the AT-802F joins in with other aerial assets, making ‘surgical’ drops, attacking hot spots, closing gaps in retardant lines, or pretreating fuels beyond the main fire. Its versatility is always in high demand.”

While Air Tractors play an important and unique role, it is only one tool of the fire agencies, and other aircraft such as helicopters and large aerial tankers are also needed. Holding also says that aerial firefighters are there to help the teams fighting the fires on the ground. “We are part of an overall strategy and aerial firefighting is about aiding the resources on the ground,” he reports.

This year, the Canadian Conair Group’s Dash 8-400AT airtanker (Q400AT) will be staying in Australia all year round as a result of a new, shared four-year contract between two Australian states, Queensland and Victoria. The contract period is long enough for the airtanker to remain in the country for the duration of the contract, taking an important step towards creating a sovereign aerial firefighting fleet. The two states took advantage of their staggered fire seasons allowing them to offer a 168-day minimum standby per season.

The longer contract period enables the Dash 8-400AT to remain in the country, with annual maintenance occurring in Australia during the offseason, in partnership with Conair’s Australian AOC Field Air. Longer term, multi-year contracts for airtankers are new to Australia but have been a common model in both Canada and the US since the 1960s. Prior to this contract, the country relied on shared large airtanker resources from North America, which itself has been seeing extended fire seasons with wildfires now occurring as late as December in the US (in Montana, Texas and Colorado).

At the end of the bushfire season, the two Conair Avro RJ85 airtankers return to Canada for maintenance in British Columbia before deploying to work the North American fire season.