In December, 2009, Wildfire Today covered a patent application filed by John A. Hoffman for an air tanker, in the form of an unmanned aerial vehicle (UAV), that would be transported by a mother ship and released near the fire. It would then be piloted remotely from either the mother ship or from the ground, and after dropping retardant on the fire, would land to reload, or might be a single use aircraft and would be “destroyed in the release step”. In the latter case the UAV would be “possibly constructed of frangible material so as to crash into the fire area”.
Thanks to a comment by Jerome on a recent article here about FAA approvals for the use of UAVs, we are now aware of a similar concept, this time by Nitrofirex, which appears to be based in Spain. Much more information is available about the Nitrofirex system than Mr. Hoffman’s idea.
Multiple Nitrofirex UAVs would be transported in a large mother ship and released through the rear cargo door. The folded wings would deploy and the aircraft would glide autonomously to the target then “automatically and with great precision” release the water or retardant. The small engine which had been idling would power the ship back to the tanker base where it would be reloaded and inserted back into a mother ship.
According to the company the system could also be used:
- “To combat a nuclear, biological or chemical emergency
- To act on meteorological phenomena.
- To combat pests or to spray crops in remote or inaccessible areas.
- For night time fumigation of drug plantations.”
We were not able to find any specifications about the aircraft regarding retardant capacity, speed, range, or cost.
Assuming that the cost, firefighter safety, and design issues are solvable, the only portion of the concept that troubles me is the assumption that an air tanker could, without a pilot either on-board or at a remote location, effectively drop retardant in the exact location where it was needed and at an appropriate height above ground. In flat terrain over a slow-moving fire this might be possible, but in mountainous areas it would be a challenge. Especially if a “squadron” of them were released at the same time.
What if…. an orbiting aircraft or a ground-based firefighter a safe distance away had a laser designator which the UAV could use as a target? Much like the military does for smart bombs and missiles. Terrain-following radar such as that used in the F-111C could make the drops more accurate and effective.
The company has developed a video which explores the UAV air tanker concept.