Aviation in Firefighting

Aircraft in operation

Aircraft are routinely involved in nearly every fire call to provide observation and firefighting support, and are ready to respond within 15 minutes of call during the long daylight hours of summer. The response time is guaranteed by the completion of daily aircraft checks each morning, with engine runups and batteries charged to reduce ground time at call out. The individual aircraft in the CNR fleet also do not ‘belong’ to any one base, but are strategically stationed throughout the state to provide an effective coverage of the CNR managed lands. Aircraft are therefore able to be dispatched to any part of the state, or occasionally interstate, for particular tasks as needs arise. Once assigned to an area for tasking, the aircraft and pilot fall under the management of that area’s supervisor. Various levels of aircraft resource management ensure that aerial support becomes an integral part of the overall firefighting strategy. An Air Operations Manager (AOM) is responsible for the overall management of aircraft and for ensuring aircraft related input to incident control planning. The Air Attack Supervisor (AAS) is in turn responsible for the tactical operation of aircraft including directing firebombing aircraft to targets. The AAS is normally airborne over a fire situation in one of the JetRangers or the Squirrel, and is an experienced firefighter with intensive and recurrent training in aerial operations. An Aircraft Officer (AO) is responsible for the provision of logistical and operational support, while an Airbase Manager (ABM) manages operations at a helipad or airstrip. The unique situations that arise over fire locations often result in a large amount of air activity, such as was witnessed over Sydney during the disastrous fires of January 1994, where over 90 fixed and rotary wing aircraft were involved in firefighting and crew transport over a 10 day period in mostly terrible flying conditions. In such circumstances, the Aircraft Officer facilitates a Common Traffic Advisory Frequency and may also request a Temporary Restriction of Airspace (TRA) to control the movement of aircraft into and within the fire area. With recent changes to airspace management, itinerant aircraft may be less likely to be aware of TRAs than in the past, requiring increased vigilance by the pilot for other aircraft in addition to the fire duty aircraft in a confined area, usually in adverse conditions. TRAs assist in reducing the likelihood of itinerant aircraft in the area, and also allowing communications on discrete frequencies enabling ‘uncluttered’ communications and thereby facilitating separation. From his airborne position, the AAS will also attempt to provide information to assist pilots in maintaining situational awareness of other aircraft. Richard Alder explains, “It is true to say that with a diminishing requirement for VFR aircraft to communicate with ground services, there is probably some risk of increasing the likelihood of an aircraft not being aware of TRA – although this risk has always been present to some extent. In some areas, such as high density RAS (Radar Advisory Service) areas, the risk of itinerant aircraft not becoming aware of restricted airspace is probably diminished.” The positioning of appropriate airfields, helipads and water resources is critical to the success of airborne firefighting operations, and although the Department has well managed facilities within its own state forest lands, ground resources in other areas are not always favourable in expediting the turnaround of aircraft for refuelling and reloading. This heightens the need for the right type of aircraft in firebombing and support, and Richard Alder believes the mix that the Department currently operates is perhaps the most effective style of operation available to firefighters around Australia, and the world. “We see one of the big advantages of ag aircraft is the performance and the ability to operate close to the fire from small unprepared fields.” The choice of contracting ag aircraft shortens turnaround times, making a larger number of accurate drops possible within a shorter time. Typical turnaround times have been cut from 30 minutes to less than 10 minutes with the use of ag aircraft such as the PZL Mielec M-18A Dromader. Despite the large capacity of the Dromader, which is 2500 litres of retardant or foam, the 1000hp (750kW) engine enables the aircraft to become airborne from rough fields in less than 600m, and its agility allows it to work within the tight confines often associated with the hilly or mountainous terrain of state forests and national parks. When combined with a three to four minute reload of fire suppressant, the Dromader is a cost effective and highly efficient part of the firebombing fleet. The fixed wing firebombing aircraft use either foam or retardant and rarely use just water. The Dromader and all other fixed wing aircraft employ variable doors on the underside of the aircraft, allowing the load to be spread with different consistency over wider or smaller areas as the fire attack plan and conditions require. Additionally, a split system allows the 2500 litre load to be dropped in two loads, providing an alternative to one large volume dump. Helicopters utilise water, foam and retardant for firebombing duties, with the lighter aircraft using water carriers slung by the cargo hook and the medium Bell 212s using belly mounted tanks. The JetRanger and Squirrel aircraft must utilise nearby open water supplies such as rivers, dams or even swimming pools as a source. The French machine, modified with an uprated Allison 250-C30 powerplant, provides a greater lift capacity of 700kg, or 650 litres, compared with only 450kg for the Bell JetRanger. The Bell 212/412 combination provides a significantly greater dump, the aircraft holding 1400 and 1600 litres respectively. The 212 helos are fitted with a belly tank while the 412 employs the bucket system, and their flexibility allows them to hover over a natural source filling by a hose and pump system connected to the underbelly tank, or by landing for a four minute refill. Each of the three medium size Bells have a one hour endurance for firefighting duties and take around six minutes to refuel. ‘Firescan 2’, Cessna Titan used for aerial fire mapping. (Julian Green) Bell 212 medium lift helo with underbelly tank. (Julian Green) Medium helicopters have proved an invaluable resource, as proven in fires near Ballarat in February last year. In 28 minutes 9500 litres of water was dumped on the fires by one Bell 212, testament to the helicopter’s ability to access a wider variety of sources and landing areas. Modifications made to the rotary wing aircraft to meet CNR contract specifications include the installation of GPS, FLIR mounts, high skids for uncleared ground clearance, chute for incendiary drops and aerial seeding, winching mirrors, specialist communications and PA system. Helicopter firefighting operations are normally conducted with pilot only aboard, to maximise water and equipment uplift. Some operations in urban areas are conducted with an AAS aboard to set firebombing priorities and to observe other aircraft and obstructions such as powerlines.

The principles of firebombing

Firebombing is a precise exercise requiring the skills of pilots accustomed to flying at tree top height, and often in adverse conditions. The determination of firefighting strategies is made by the Fire Controller, taking into account such factors as weather and the related fire behaviour, fuel types, forecast weather conditions, proximity and availability of ground firefighters, availability of aircraft and the location of the fire in relation to suitable control lines such as roads or tracks. When using aircraft in attack roles, the Controller is assisted in decision making by the AAS. Coverage levels are usually determined by the AAS following consultation with the Fire Controller. Drop heights are determined by the pilot and AAS within safe limitations.

A direct attack on a fire will include firebombing just in front of any flame front using retardant or knocking down flames along the fire edge using foam or water. Direct attack is usually only made when ground support is available or extinguishment is feasible. Alternatively, given prevailing conditions, the alternative of an indirect attack may be appropriate, laying a retardant fire break along or between natural barriers, or by ‘buying time’ for fire control line construction by directly attacking the fire with retardant to slow its progress. Retardant is used primarily on remote and inaccessible fires where delays in getting ground crew support is considerable. Despite their higher cost, long term retardants are the most effective tool in combating fire. Foam, pre-mixed on the ground, is used to directly support ground crews in a knockdown role, spraying foam on the fire edge or on fuels just ahead of the fire. The foam itself is created by the shearing action of the airflow as the load of surfactant and water mix is released from the aircraft. The foam is visible for 20 to 40 minutes allowing the pilot to judge areas for further drops. Water alone is only effective in support of ground attack. The fixed wing aircraft are not suitable for water-only operations because it does not smother or penetrate as effectively as foam or retardant. After establishing an anchor point, pilots fly a circuit over the area to be bombed, much like flying an approach circuit. The release is preferably made downhill and downsun, and into the wind to provide the best accuracy. Drops are planned so that they can be extended or intersected effectively, and are monitored to adjust the attack accordingly. Direct dumps on a fire head are usually avoided because of the convective activity and smoke which increase the risk of accidents through loss of control and/or pilot disorientation. Supporting the airborne fixed wing firefighting efforts, helicopters are also used in the transport and utility role, moving crews into and away from fire scenes. The medium Bell helicopters are used in rappelling crews into areas where no landing site exists and which are inaccessible by road. Normally five crew descend by rope from a hover at around 150 feet, followed by firefighting equipment. The 212 or 412 may also carry a load of water or foam in the underbelly tank or bucket to assist the ground based efforts. This method of firefighting has proven useful in terrain around the alpine areas of Victoria where fires can take hold within a short period following lightning strikes from storms. With road access limited in such areas, the ability to fight the fire before it becomes a ‘campaign fire’ is invaluable in not only saving the natural resources of the area but in containing the expenditure involved in committing large numbers of crew and field support to longer term fires. “Keeping small fires small is what it’s all about,” says Richard Alder, pointing to the fact that combined use of fixed wing firebombers and helicopters as crew ships are a very effective way of containing fires before they take hold in larger areas. Rappel crews undergo training every two to three weeks at Benalla in eastern Victoria. Crew leaders also undergo this regular currency training in addition to a supplemental annual programme of intensive training involving techniques and crew leadership. Another method of deploying personnel in remote areas is the hover exit, used when a full skid landing cannot be made because of ground vegetation or terrain. This method is used in the High Plains, desert heathland areas and scrub rock areas of the Grampians. The method was originally developed in Canada and was introduced by the CNR in 1991 after modification to the Canadian techniques to suit local conditions. The maximum exit height for hover exit crews is 1.3 metres, and the Department has approval for this technique for all of its helicopters in contract. All CNR rappel crews are also capable of conducting hover exits.

Aircraft Support

The CNR has also developed a comprehensive array of ground based support equipment for aircraft in the field. Thirteen fixed bases are located throughout the state and supplemented by mobile services taken directly to landing sites during fire operations. Four ‘hot refuelling’ trailers support air operations in remote areas, using aviation fuel supplies carried onboard the trailer as well as bulk fuel provided by arrangement with local suppliers. Seven mobile retardant mixers are also deployed to the field as required. With two aircraft able to be processed simultaneously, these mobile services greatly reduce turnaround time of aircraft and enhance the firefighting capabilities of air and ground forces. The field based refuelling, loading and mixing equipment used by CNR has been developed inhouse by a research and development unit at Altona, which provides a high level of technical support to field operations by designing and producing equipment specific to the Department’s unique requirements. Ideas are often brought in from overseas and adapted for use by the Department, often including enhanced safety features. Communications and command is made available in remote areas by four mobile airfield command centres. The CNR is among all Victorian state government departments to be linked into the new dedicated trunk radio system comprising emergency services, police, ambulance etc. The Victorian Public Sector Mobile Radio Network hardware has been fitted to all CNR vehicles including aircraft allows more effective coordination of ground and air activities with those services of the other participating agencies.

Cnr Technologies At The Leading Edge

The Department is widely recognised as a leader in the areas of aerial fire suppression, and it is also gaining world acclaim for its development and demonstrated success of fire mapping and sensing technologies. One of the most significant developments by the Air Operations Section’s Systems Officer, Andrew Matthews, is Firescan, a highly sophisticated computerised image processing facility specially developed for obtaining intelligence on fires. Loaded aboard Firescan 2, the CNR’s Cessna 404, the airborne infrared/multi-spectral/ultraviolet line scanner is able to detect and record fire activity by sensing IR radiation generated by a fire. Simultaneously the scanner records background information such as terrain, streams and roads which assist in planning fire suppression strategies, taking into account access, proximity to populations and assets, as well as the fire behaviour. Firescan also transforms and rectifies the data and overlays the fire information on a standard topographic map. Typically, Firescan 2 will fly at around 10,000 feet at a speed of 170kt (315km/h) taking images of four kilometre strips directly beneath the aircraft. Temperature differences of as little as 0.2°C can be detected by the system. Data is produced onboard and can be printed as a hardcopy to be faxed from the aircraft to a control centre or released through a chute in the aircraft at low altitude to be collected by ground crew at an airfield. Alternatively, the information can be modemed via the new trunk radio system to a control centre where it can be converted to a hardcopy for planning and strategy development. The information generated by Firescan complements the information obtained by the CNR’s FLIR. Mounted in the light helicopters, the FLIR is used to obtain more localised information to direct crews to potential trouble spots. Another CNR development is the Automated Real-time Mapping System, or ARMS, which has been developed in conjunction with Global Star for fire mapping. Used from any vehicle, but most effectively in the Department’s light helos, the ARMS kit includes a GPS, laptop computer with printer and uninterruptable power source. The aircraft is flown around the fire edge while the ARMS software records the track of the aircraft using GPS information which is then automatically referenced to the Australian Map Grid, providing current position in relation to roads as well as latitude and longitude. ARMS has been purchased by authorities in all states and territories of Australia, making it the de facto Australian standard for automated fire mapping. Overseas interest in the system is also increasing.

Cnr And The Issue Of Aircraft Suitability

“You have to consider whether, for the same investment, it is more effective having a few large aircraft at a limited number of locations, or a larger number of smaller aircraft spread over a greater area providing a better fire strategy”, says Richard Alder in discussing the much touted question of whether Australia should be looking to larger and more sophisticated aerial firefighting machines. The CNR has developed an awesome aerial firefighting capability, which has become the focus of attention from the United States and Canada, as well as elsewhere in Australia. Clearly, it has focussed on the use of smaller aircraft to fulfil the role of what has traditionally been the realm of larger types such as the DC-6s, Neptunes and C-130s contracted by the US Forest Service. The F27 and DC-6 have also been assessed by CNR, but although more favourable drop patterns were available from these aircraft, the turnaround time in practice was considered too great. Smaller agricultural aircraft are suited to unprepared and short fields and have the agility to work in high stress environments. So, too, helicopters have the ability to set down from tight and confined spaces to take on personnel and suppressants. This mix has worked well for the CNR and it sees no necessity to change from this philosophy. In the 1981/82 and 1982/83 seasons a C-130 was fitted with a modular tank system, capable of uplifting 11 000 litres. In assessing the aircraft’s suitability to the role the Department considered the turnaround time of the aircraft its ability to use existing airfields adjacent to known fire sources and its drop pattern. The CNR judged that the C-130 with a modular pack would not provide sufficient enough canopy penetration for the unique eucalypt forests of Australia, and that the turnaround time was too great to be effective. In short, it was considered that the aircraft would be useful approximately once in every 12 to 14 years in the instances of widespread intense fires. More recently, the CNR has assessed the Canadair CL-215 and CL-415, and the Eurocopter Super Puma. All aircraft are said to have similar operating costs of around $A2500-$A3000 per hour and possess similar load capacities. “One argument says that the Super Puma, which carries roughly the same load as a CL-215, is more practical in Australian operational conditions than the Canadair because it can fill from a wider range of water sources in an environment where water is more scarce than in Canada.” The costs of the aircraft in Australia are $A24 million for the brand new CL-415 (secondhand CL-215s would be considerably less) and around $A18 million for the Super Puma. It is considered unlikely though that any Australian organisation would import any of these aircraft purely for seasonal fire use, and National Jet Systems of Adelaide’s plans to import two Canadairs have proven fruitless to date. Richard Alder prefers the ag aircraft solution and believes that interest in the next generation of firebombers in Australia should be directed to the Air Tractor AT-802 series. “The AT-802 is as large as you can get while still maintaining the advantages of an ag style of aircraft,” he says. “With a capacity of 3200 litres, the AT-802 was originally designed in the United States as a firebomber in an environment which, until recently, has continued to believe that bigger is better. With the advent of the AT-802 however the US is following the path of the CNR in Victoria in recognising the value of smaller and more flexible aircraft in the firefighting role. It is now introducing the SEATs (Single Engine Air Tankers) for forest duties and the AT-802 is gaining wider acceptance. There are presently three of the type in Australia being used as ag sprayers.”

Future directions

While Richard Alder and other fire management specialists do not expect other states and territories in Australia to conform to their own model of operations, they see great opportunities to cooperate and streamline fire suppression techniques and procedures. Greater interstate cooperation has resulted from CNR’s demonstrated successes in aerial fire combat techniques and other agencies are using the Victoria’s experience to further develop their own strategies and fire crew training. Around 200 people of agencies responsible for fire management from most states and territories in Australia are trained in aviation management and support each year by the CNR. It is unlikely that Australia will see the likes of the CL-415 or Super Puma on the permanent register as firebombers though it would be interesting to see these aircraft tested in a real situation such as was experienced in January 1994 in New South Wales. The combination of small rapid response aircraft and helicopters provides an aerial firefighting capability that Australia has only recently become aware of, and it is one that the CNR has lead the way with. As one CNR member said, “It really is quite a big little air force.”

The Cnr In Sydney

The Department was involved in the Sydney fires from 5th to 16th January 1994. During this time, 50 CNR staff and 14 of the contracted pilots were directly involved in fire suppression in the northern suburbs and the Blue Mountains. The three medium Bell helicopters flew 133 hours while the light helos flew 122 hours. Six fixed wing aircraft flew 148 hours while the new Firescan system, introduced just weeks before the fires, flew 20 hours. Thirty two tonnes of retardant was used and 3500 litres of foam concentrate. Helitack 1, the Bell 412, flew the most hours with 59 hours in eight days, in one day dropping 118 loads in nine hours. Australian Aviation would like to thank the Department of Conservation and Natural Resources for their assistance with this article. Further information about the CNR’s Air Operations can be obtained from Richard Alder on (03) 9412 4444.