Fire Management – 101. Helicopters.

Helicopters capitalise on the three main advantages of aircraft… speed, access and observation…

The RAAF’s first helicopter, a Sikorsky S-51 Dragonfly (A80-1), was test flown at Laverton Air Base on 9 October 1947.

In May 1949, in an Australian first, the Forests Commission winched firefighters from the hovering Dragonfly.

The Sikorsky proved very versatile and was later used for reconnaissance and mapping missions as well as deploying fire crews and their equipment into remote locations.

Based on these successful RAAF trials, as well as experience in the 1965 Gippsland bushfires, the Commission contracted its own Bell 47G in late 1965, which was also an Australian first for any forest agency.

Development of rappelling techniques at Snowy Plains and Tallangatta followed, which led to operations based at Heyfield with a two-man crew to quickly attack small fires in remote locations.

The Heyfield rappel crew was another Australian first and remained in place for the following two fire seasons but lapsed after concerns from the Civil Aviation Safety Authority (CASA) about the stability of the small and underpowered Bell 47G.

However, the Forests Commission continued to expand its use of light helicopters throughout the 1960s and 1970s for transport, sling-loads, reconnaissance, mapping, aerial seeding, spraying, Forward-Looking-Infra-Red (FLIR) cameras and developing aerial incendiary techniques.

A notable feature of the January 1978 fire season was the very important part played by larger military helicopters. Three RAAF Iroquois were used to move crews and supplies across the Victorian alps. This was probably the first-time military helicopters had been used to support Australian firefighters on such a large scale.

It was a game-changer…

The National Safety Council of Australia (NSCA), which was based near Sale in Gippsland, expanded its aerial operations significantly during the 1982-83 bushfire season.

In 1982, after nearly 18 years absence, rappelling operations recommenced using larger and more powerful NSCA Bell 212 and Bell 412 helicopters.

A NSCA Bell 212 with a 1700 litre water bucket was first used at the Seaton fire in November 1982. If a water source was nearby, the bucket proved very effective at supporting ground crews at knocking down spot fires and supressing flames.

Also, during the Ash Wednesday bushfires in 1983, a 30-passenger RAAF Chinook helicopter deployed firefighters, relief crews and fuel for bulldozers in difficult terrain at Nug Nug near Mount Buffalo.

The NSCA later conducted its first firebombing operations in Victoria using Canadian designed helicopter bellytanks in 1983-84.

Valuable lessons about using aircraft, particularly at the 1985 bushfires at Mt Buffalo, led the Department to initiate national training programs and accreditations for aircraft officers, observers, incendiary operators, hot refuelling crews, retardant mixers as well as specialist Air Attack Supervisors (AAS).

The Erickson Sky Crane first came to Victoria in 1997-98 and could lift nine tonnes of water.

Modern firefighting operations are generally conducted with a mixture of both fixed and rotary wing helicopters. But helicopters have a major advantage over fixed wing aircraft of being able to hover over the fire and accurately drop water, foam or retardant. They can pick up water from shallow dams or rivers using snorkels to fill their belly tanks or dipping a collapsible bucket suspended on a line. Helicopters can also be used for reconnaissance, air attack, infrared mapping, dropping supplies and delivering crews.

Depending on forest type, fuel load, understory thickness and slope, a large Type 1 helicopter like a Sky Crane can construct, suppress and hold about 500m of control line per hour. A mid-size Type 2 Helicopter like a Bell 412 with a bucket or belly tank might only achieve 200 m.

For comparison, the sustained rate to construct and hold fire control lines by hand crews is between 5 and 20 m per person per hour.

The operating costs of medium helicopters are much higher than fixed-wing aircraft carrying similar loads but their flexibility, accuracy and ability to pick up retardant close to the fire can make them more cost effective in many situations.

They are particularly effective in tight mountainous terrain and providing close support to knock down flames for ground crews working near the fire edge. But there is no substitute for “boots-on-the-ground”.

But the greater use of heavy-lift helicopters forced major changes to fuel and retardant handling. Medium helicopters like the Bell 412 require about 600 litres of fuel per hour, or three standard 200 litre drums, whereas heavy-lift helicopters like the Erickson Air Crane were fitted with massive 4,900 litre fuel tanks and guzzled a staggering 2,000 litres per hour.

Helicopters have continued to evolve and are now an integral part of bushfire suppression.