What’s New in UAV Propulsion? 

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In the unmanned aerial vehicle Group 3 and Group 4 range, electric motors do not provide enough power and companies often try to repurpose motorcycle engines or rotary engines designed for other purposes, with poor results.

Rather than relying on batteries and rotors, an American startup – UAV Turbines – is developing a miniaturized jet engine, a microturbine engine engineered specifically for Group 3 UAVs, which could benefit military and commercial users alike.

The jet engine generates 200 horsepower and runs on standard jet fuel, an advantage for potential military users who operate in remote locations where electrical charging infrastructure doesn’t exist.

The company believes its Monarch 5 class of engines could improve US Army UAV propulsion in the smaller Group 3 and Group 4 range. 

UAV Turbines introduced a lightweight recuperator for the first time in a flight weight micro turboprop, providing better fuel efficiency.

Kirk Warshaw, UAV Turbines president and CEO, told Janes.com that it has been tough in the past to develop a small turbine engine because the turbine technology does not scale down well. UAV Turbines, he said, recruited engine designers from industry leaders such as Pratt & Whitney and Rolls-Royce and has designed a microturbine engine that can spin at 160,000 rpm, which he said is faster than any UAV propeller engine can spin.

This summer, the company flew the Monarch 5 in a compact fixed-wing drone weighing about 500 pounds, with a 22-foot wingspan. This quiet jet engine can power propellers, generate electricity for electric motors, or even produce its own thrust. 

And while pocket-sized jet engines have been boosting radio-controlled model airplanes for decades, the company calls the Monarch 5 the first commercial-grade microturbine, according to wired.com.

The engine is one of the smallest commercial-grade variable pitch propellers, which is common on turboprops and regulates aircraft speed by altering the angles of the propeller blades instead of revving the engine up or down.

The development has potential for the eVTOL market for passenger-carrying aircraft, where, the microturbine could supply electricity to batteries powering motors in hybrid configurations. 

It would also go into the civilian drone market, helping move cargo, inspect infrastructure, build maps, and deliver packages.