Jet suit packs five microturbines to boost pilots up, around, and through obstacles, demonstrating a new way to fly. Photos: Gravity Industries

Iron Man Lives

Jul 12, 2019

by John Kosowatz

Aviation buffs looking for stripped down flight experiences have the option of flying a hang glider or an ultralight aircraft. For those looking for a more powerful option, how about strapping on a cluster of gas turbines and powering yourself into the air at speeds approaching 55 mph? Fantasy becomes reality with a jet suit developed by a British entrepreneur who wanted to make human flight a reality.

Richard Browning, CEO of Gravity Industries, is a former Royal Marine without any formal background in aviation. Through trial and error and with a small team of electronics, propulsion, and additive manufacturing professionals, he designed a jet suit that now is commonly compared to the superhero Iron Man. So far, he’s reached heights of 60 feet and speeds of 89 kilometers per hour. “But this is only limited by safety,” he said. “We could go higher and faster.” The jet suit is a backpack housing electronics, fuel systems and a rear jet engine. The arm assemblies house the controls—a trigger and throttle adjustment switch—and two engine clusters, one for each arm. The microturbines burn four liters of jet fuel per minute, with a typical capacity of 40 liters, said Browning. Fuel tanks are located on either side of the engine on the backpack. Jet fuel is less combustible than gasoline, a safety feature built into the design, he said.

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Browning said the average time for a novice to hover is about 15 minutes, although a trained gymnast mastered the suit and procedure in just four minutes. The original learning curve of controlling his body with the thrusters was developed in trial and error over three years, he said. The thrust balance is similar to a camera tripod, with roughly one-third on each arm and the backpack.

“Human balance and control is very capable of adapting to many advanced control problems,” said Browning. “Think about a top-heavy human running across an uneven field. This can be adapted and fine-tuned with proper training. The control is further enabled by a series of thrust vector geometry optimizations across the entire jet suit that we have learned over three years.”

Browning said his lack of a formal background in aeronautics helped to shape the design without any preconceived ideas. His father was an aeronautics engineer and inventor, and his grandfathers were pilots so Browning grew up around engineers. Still, “I’m not burdened by conventional aeronautics training,” he said. “I didn’t know what wasn’t supposed to be possible.”

That thinking led him to microturbines. “They offer the highest thrust-to-weight ratio of any microscale propulsion device,” Browning said. “They have a small bounding volume with no external rotating surfaces. But there’s no rule book on how to do this. We have had to start from scratch on every aspect of the design, so adapting and making use of existing technology has been key to overcoming development challenges.”

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Browning is keen on training new pilots—six are currently capable of doing public performances—and starting an international racing series. The ride is considerably noisier than an ultralight aircraft. Gravity sells the suits for $443,000 and Browning said two have been sold, with the money being reinvested in development. Flying the dream does not come cheap.

John Kosowatz is senior editor at ASME.org.