Drones have long proven their worth when it comes to reconnoitering locations and fire incidents, and that raises the question of whether unmanned aerial vehicles could also be used to actually put out the fire. To find out, Riga-based startup company Aerones converted one of its heavy-duty drones into a fire-fighting UAV. The team wanted to establish how high it could reach and identify the challenges the drone pilot would have to overcome in various deployment scenarios due to the kick back from the water exiting the hose.

The drone that was put through its paces in Treffling measures 3 meters in diameter, weighs 70 kilograms and can carry a load in excess of 100 kilograms. During the test flight it reached an altitude of a good 85 meters while delivering some 100 liters of water per minute. To ensure the drone wasn’t restricted by a limited battery charge, it was supplied with power through a cable. To fight the fire, Rosenbauer fitted the drone out with a NEPIRO high-pressure steel nozzle that was connected via a free-hanging high-pressure hose running alongside the power cable to a vehicle. The vehicle, also from Rosenbauer, featured an NH pump with a high-pressure stage that generates a standard output of 400 liters per minute at 40 bar. Nevertheless, the experienced drone pilot was able to compensate for the recoil effectively and hit his target with impressive accuracy.

Even though there is still a lot of development work to do, the test showed that drones are fundamentally suitable as fire-fighting equipment. What's more, using compressed air foam instead of water could significantly extend the discharge height of the extinguishing agent. In fact, Rosenbauer has already proven this, achieving discharge heights of up to 400 meters with SKYCAFS.