The dangerous nature of airborne firefighting has led to widespread international interest in the potential of unmanned air vehicles to carry out all or part of the mission as a way to reduce risk to aircrews.
However, many technical hurdles have yet to be resolved and the ability of a UAV to perform the retardant delivery mission seems unlikely in the near term. The often treacherous micro-climate that surrounds a major fire would require a UAV to display robust dynamic performance, advanced autonomy, support advanced sensors to see through the smoke to follow terrain and locate the fire front, and carry a high-level sense and avoid system to allow it to fly in close proximity to other manned and unmanned firefighting aircraft. Such capabilities mean significant cost.
UAVs are more likely to be used as part of the fire management command and control architecture, says Brian Mansell, managing director of Canberra-based Australian Technology Information (ATI). He says UAVs are currently able to perform two key roles: localisation of the fire front using infrared sensors, and establishment of communication networks in remote or fire-affected areas. ATI is investigating both applications as part of its contracts for emergency services command and control with Australian government authorities. An early pointer, Mansell says, is the need for the UAV to be rapidly deployable.
The fire-spotting role received international attention in August 2004 when General Atomics Aeronautical Systems used its Altair UAV to monitor wildfires burning across Alaska. The Altair was already deployed in Alaskan airspace for maritime surveillance missions and was retasked at short notice. While the mission was considered successful, the cost of top-end UAVs means their use as dedicated firefighting systems is unlikely.
Russian aerospace group Irkut believes a lower-cost solution is to use more capable tactical UAVs, given their market proliferation. The group hopes to secure certification from the Russian authorities this year to use a modified Aeronautics UAV as a fire spotter for cueing retardant delivery by Beriev Be-200s.
The potential of even smaller UAVs for fire spotting is being studied on both sides of the Atlantic. The Hungarian National Defence University and the rural-based Szendro municipal fire brigade have spent three years looking at whether UAVs could provide smaller response units with an organic airborne fire reconnaissance capability. During July and August 2004 they used a large hand-launched UAV carrying a CCD camera to monitor spot fires in light wind conditions. Key lessons, say Szendro brigade officials, include the need for meaningful UAV endurance and a higher order of autonomous behaviour to reduce operator workload.
Last September the Idaho National Engineering and Environmental Laboratory and NASA demonstrated a purpose-developed 3.6m (12ft) wingspan UAV in the fire-spotting role. Ongoing work is looking at how flocks of small, inexpensive UAVs equipped with different sensor types could aid firefighters.
PETER LA FRANCHI/CANBERRA
Source: Flight International
