As was demonstrated again this summer in the Mediterranean, firefighting aircraft or helicopters are indispensable in the fight against major forest fires. Airplanes can quickly throw large amounts of water into hard-to-reach fires. The German Aerospace Center (DLR) has been organizing design challenges for young researchers for six years. This year’s task was to design the firefighting aircraft of the future.
Current firefighting aircraft are usually converted military aircraft, older airliners or helicopters with firefighting tanks. There are only two specialized firefighting aircraft in production worldwide. Both are amphibious flying boats that can land on water as well as at airports.
The Canadian company De Havilland Canada has produced the CL-415 since 1994, which can carry up to 6000 liters of water. The Russian Beriev Be-200 flying boat has been flying since 1998 and is the size of a small airliner. The extinguishing capacity is 11,000 liters of water. CL-415 is used in France, Spain and Greece, among others.
DLR Design Challenge 2022
This year’s design competition wasn’t just about futuristic aircraft design. The task was to design aircraft with an extinguishing capacity of at least 11,000 liters of water during one extinguishing flight. It was also allowed to design a fleet of smaller aircraft such as drones that together meet the conditions.
- The aircraft must be able to take in water at airports, from lakes, rivers or the sea.
- They can be pilot-controlled, remotely controlled from the ground or fly autonomously
- They must also be able to be used at night and in poor visibility conditions
- They must be able to deliver large quantities of water to the fire scene within 24 hours
- The aircraft must also be able to be used as a passenger or cargo aircraft
- The design must be possible to build by 2030 at the latest.
The winning design: INFERNO
First place went to the team from the University of Stuttgart with the INFERNO design. (Intelligent Fire Response Operation). The aircraft is a so-called combination helicopter. With eight horizontal rotors, it can take off and land vertically. The drive is provided by a hybrid electric system, where a gas turbine supports a rechargeable battery and the electric motors. INFERNO can absorb water as it skims low over the water, hovers upright over a lake and sucks water into its tanks, or simply takes water into an airport. This unit can therefore also take water into small waters, where it is impossible for the current fire-fighting aircraft.
Second place ‘PE-L-FAN-T’
The TU Dresden team took second place. With ‘PE-L-FAN-T’, the students designed an autonomous drone with four lifting propellers and two thruster propellers. The lift propellers enable the drone to take off and land vertically, while the drag propellers provide propulsion. The abbreviation “PEL-E-FANT” stands for “proPEllor-powered turbo Electric hybrid Firefighting AutoNomous vTol” or “propeller-powered hybrid electric autonomous vertical takeoff firefighting drone”. Depending on the task, modules are mounted under the central body. For firefighting tasks, a multi-machine formation is used, two of which have reconnaissance modules to locate the fire and coordinate the flow of water.
Third Place: ‘FireWasp’
Third place went to “FireWasp” from the Rheinisch-Westfälische Technische Hochschule (RWTH) in Aachen; a combination of helicopter and plane. The ‘FireWasp’ also flies with a conventional gas turbine. But like in “INFERNO” it is powered by synthetic alternative fuels. The “FireWasp” takes in water via a snorkel pump and can therefore also use less water to collect firewater. In case of forest fires, a formation of six fire wasps fights the fire. The fleet is coordinated by a reconnaissance helicopter that also monitors the effectiveness of the deployment. The seven machines are an autonomous drone swarm and are controlled from a mobile ground station.
Firefighting boat GLAROS
A joint team of students from TU Dresden and TU Braunschweig took fourth place with GLAROS. The design is an autonomous flying boat that, like the CL-415 or Beriev Be-200, absorbs extinguishing water while hovering over the water. GLAROS can deliver large quantities of water to the fire over longer distances. The propulsion power for the twelve propellers, distributed on both wing leading edges, is provided by a turbogenerator and two batteries. The gas turbine runs on conventional or synthetic fuels.
The University of Baden-Württemberg in Ravensburg sent two teams to the DLR Design Challenge. The ‘Dipper’ team submitted a rather conventional design. ‘Dipper’ is an autonomous amphibious flying boat with eight propellers spread over the wing. This design also uses a hybrid electric drive system to power the counter-rotating propellers. The young scientists have developed special software to coordinate the deployment of a Dipper fleet. During firefighting operations, six flying boats fly in formation.
Autonomous firefighting helicopter
Ravensburger University’s other design is the “Firef(l)ighter”, a gyrocopter powered by a conventional gas turbine. Two propellers provide propulsion, the short wings and the large rotor provide lift. The ‘Firef(l)ighter’ is also unmanned. The gyroplane fills its water reservoir via a piston, which it can lower into, for example, a lake or river. The fire-fighting work must be carried out by a fleet of ten machines. A multi-person team on the ground would oversee the operation.
Main photo: “FireWasp” is a combination helicopter and plane. © RWTH Aachen