Inside-WIBy Tom Still

MADISON, Wis. – Dave Kettner, the president of Madison-based Virent Inc., doesn’t make a habit of hanging out with international celebrities, but he did so last fall on a transatlantic flight with billionaire Sir Richard Branson.

It helped that Kettner’s firm supplied much of the sustainable aviation fuel that entirely powered Virgin Atlantic’s “Flight 100” in November 2023, the first such transatlantic crossing by a commercial airline.

So, what kind of person was Branson? Kettner recalled an energetic man who spent much of the eight-hour flight on his feet engaging with other passengers. But the real star was Virent’s BioForm fuel, which can be made from all types of plant-based material and safely dropped into jet engine tanks without the need to blend with conventional fuels.

It’s one example of innovation in the aviation industry taking place in Wisconsin, which already has a rich history of powered flight “firsts” that range from fighter pilot aces to early astronauts to the world-renowned air show of the Experimental Aircraft Association in Oshkosh.

The kind of transformation underway in Wisconsin and elsewhere today has a chance to alter the carbon-based footprint of the industry through new fuels, new engines and new ways to move people and cargo through airports.

Speaking April 23 to members and guests of the Wisconsin Technology Council, Kettner described how Virent’s sustainable fuel performs just as efficiently as carbon-based fuels in commercial aircraft. At a time when climate change is compelling innovation in most forms of transportation, Virent’s 22-year journey to get the technology right has come of age.

“The world will always assume something can’t be done… until you do it,” Branson wrote during the November 2023 flight from London-Heathrow Airport to New York’s Kennedy International Airport. “This flight today shows that sustainable jet fuel can be used as a drop-in replacement for jet fuel – and it is the only viable solution for decarbonizing long-haul flights.”

What must happen next is scaling the production of such fuel, which can be made from carbohydrates and sugars found in plants or byproducts – including corn stover, whey, paper production waste, cooking oil and more. That suggests a potential supply chain in Wisconsin, assuming such material can be economically transported to plants to refine it into quantities sufficient to make a difference.

The Sustainable Aviation Fuel Grand Challenge, announced in 2021, aims to expand domestic consumption to 3 billion gallons in 2030 and 35 billion gallons in 2050 while hitting at least a 50% reduction in lifecycle greenhouse gas emissions.

Speaking at the same event was Jon Heup of DeltaHawk Engines, a Racine-based company that recently signed an agreement with Piper Aircraft Co. that could lead to the production of a jet-fueled, piston engine for installation in Piper’s PA-44 Seminole twin-engine planes.

The DeltaHawk engine is already certified by the Federal Aviation Administration, and once further testing is completed it could be installed in large numbers in Piper’s new and retrofit aircraft. Heup described it as the most revolutionary aircraft engine design in 60 years.

How big is the general aviation universe? There are about 205,000 such airplanes in the United States and another 135,000 around the world, according to recent estimates. It’s also an older fleet that could use modernizing, which may put DeltaHawk in a position to soar.

Worth mentioning: The DeltaHawk engine can burn the same type of sustainable aviation fuel produced by Virent.

Aviation efficiencies aren’t just happening in the air, however. Paul Strege, who leads Mead & Hunt’s aviation services in the Midwest, told listeners that better engineering and design is helping airports move people, luggage and cargo more efficiently while saving energy. The company’s Wisconsin offices work with airports and related industries across the region – including the Dane County Regional Airport for nearly 80 years.

Better fuel, better engines, better experience on the ground. The next time you fly, remember that innovators in Wisconsin are trying to uplift it for all.

Still is president of the Wisconsin Technology Council. He can be reached at