Hirth Engines makes two-stroke engines for ultralight aircraft, unmanned aerial vehicles (UAVs), and other light aviation applications.

Speaking at Xponential Europe in Dusseldorf, Peter Lietz, Head of Hirth International Sales and Services, told Inside Unmanned Systems, “We have a range of engines for a range of needs, from eight hp [horsepower] up to, currently, 70 hp. Right now, we are strongly promoting our heavy fuel applications, with two engines that run on heavy fuel and jet fuel, in the 50 hp and 60 hp range.”

RELATED: See IUS deep dive on Hirth Engines’ technology.

The demand for jet-fuel and kerosene-fuel engines is rising. “We are hearing from our military customers about the single fuel concept,” Lietz said, “where, on the battlefield, they want to be able to power all of their systems with the same type of fuel.” The single fuel concept (SFC), also known as the heavy fuel policy, is a military logistics strategy aimed at standardizing fuel types on the battlefield, primarily focusing on jet propellant as the universal fuel for ground and air vehicles.

“This would improve efficiency,” Lietz said, “running jeeps, tanks, helicopters, and UAVs.” Important partners for the Hirth company include UMS Skeldar, which makes the V-200, a rotary-wing UAV using Hirth’s 35HF heavy-fuel engine. The V-200 has been deployed by the German Navy for reconnaissance missions.

Martin UAV has also integrated Hirth in its V-BAT. This state-of-the-art vertical take-off and landing (VTOL) UAV uses Hirth’s 4201, air-cooled, two-stroke, 15 hp, boxer engine. In tests conducted at Camp Roberts U.S. Army Base, the V-BAT achieved a flight altitude of 15,000 feet and covered a distance of 50 miles, demonstrating the enhanced capabilities provided by the Hirth engine.

“We have also installed our 41 series engines on the Rheinmetall’s Luna UAV,” Lietz said. The Luna is designed for intelligence, surveillance and reconnaissance (ISR) missions and is widely used by European military and defense forces.

Broadening the field

“We have non-military customers, one in the UK called Windracers,” Lietz said,” which does autonomous cargo drones.” The Windracers ULTRA MK2 is designed for efficient middle-mile logistics. “They are right now busy with humanitarian operations in Ghana,” he said.

Also invaluable for light aircraft operations is Hirth Engines’ 23 Series, a line of air-cooled, two-stroke engines known for their exceptional power-to-weight ratio, particularly suitable for aircraft weighing under 120 kg. “So we’re living in both worlds,” Lietz said, ” military and civil, and we have customers all over the globe, from Australia to South America, in the U.S., in Israel, China and Africa.”

Hirth’s presence in a diversity of markets gives the company a unique perspective on the UAV world. “On the topic of regulation,” Lietz said, “we have seen the Indian government taking quite a smart approach, working on design and manufacturing standards. This is something that the FAA and EASA have not done, instead focusing on operational safety, pilot licensing, and airspace integration, rather than regulating how UAVs should be built.”

2028 will mark 100 years of Hirth Engines, but in the meantime, Lietz said, he’s looking forward to next year’s Xponential Europe. “We’ve had a very good audience, good discussions and a great mixture of exhibitors. The European UAV market is growing massively; with a lot of start-ups, smart solutions, and smart ideas, and I think this is the perfect platform to demonstrate that.”