Making history in the air is nothing new for Iturmendi, who moved to Sarasota in 1998. Originally from Spain, his first job after grad school at Oklahoma State University included piloting an air ambulance to fly organs to hospital surgery rooms. In 2016, he was the test pilot for the $260 million Swiss Solar Impulse project, which led to the first solar-powered plane circumnavigating the globe. He’s flown more than 190 types of air vehicles and has been the experimental test pilot on many prototypes.

In 2018, Iturmendi co-piloted the Airbus Perlan, a pressurized glider that harnesses the power of wind to travel, reaching 65,000 feet and earning a world record for altitude in a glider. During the trip, he also achieved the fastest known speed for a glider at Mach 0.48—roughly half the speed of sound. The Perlan glider, which is designed to soar up to 90,000 feet, also passed the Armstrong Line, the point in the atmosphere above which an unprotected human’s blood will boil if an aircraft loses pressurization. Iturmendi is also the youngest recipient of the Living Legends of Aviation award, which actor John Travolta presented to him at a 2019 ceremony in Austria.

In December 2021, Iturmendi founded Helios Horizon with project manager Javier Merino and a handful of international engineers and academics who visit from Europe and around the U.S. to help out throughout the year. The project is mostly self-funded, with additional support from some local private donors, like Tina and Mike Willeford of Lakewood Ranch, and sponsorships.

“There’s no lucrative part of this,” Iturmendi says. “Four hundred thousand dollars came from me, in cash; a lot of the hardware I already had; and I own the warehouse space. Sometimes there’s product sponsorship, but it’s an academic project first. We spend more than what we get.”

The Helios Horizon plane has a carbon-fiber frame and an 88-inch propeller that’s mounted at the end of a 4-foot mast. As it rises, it can reach 90 miles per hour before it hits a fixed cruising speed of 60 miles per hour. The motor is just 8 inches in diameter and 4 inches thick; it weighs 20 pounds and costs roughly $3,000. (For comparison, a combustion motor is 15 times heavier and costs 10 times as much.) The custom-made batteries are worth $18,000 each and require two to six per flight, depending on altitude. One of Iturmendi’s goals is to prove that electric aviation isn’t just cleaner than fuel-powered aviation—it’s cheaper.

Before year's end, his aim is to reach an altitude world record of 30,000 feet for electric aircraft weighing less than 500 kilograms. Powered by four custom electric batteries with Iturmendi behind the yoke, the modified plane will take off from Nevada’s Minden-Tahoe Airport and land after cruising more than five miles high over Lake Tahoe.

It sounds exhilarating, but Iturmendi says being ensconced in his tiny, solo-passenger Helios aircraft is no joyride. The main risks include being in an unpressurized plane, which he mitigates with a custom suit and helmet. The potential for the plane’s batteries to overheat, a common threat in high altitudes, is kept in check with custom-built cooling systems.

But Iturmendi doesn’t dwell on risk as much as reward. He says he takes as many precautions as possible and is continuously having Helios Horizon’s work peer-reviewed, along with performing regular engineering checks and tests. “Thanks to the precautions I take, I don’t consider it a huge risk,” he says.

How does it feel up there? “Once I get to the high point, I might relax just for a second, but then I get into high-stress work mode and just get laser-focused on the task,” he says. “The joy hits when you land back on the ground and you’re OK.”

The aim of the work, according to Iturmendi, is to prove that fuel-less flying isn’t just hype. “The proof is in the performance,” he says. “Naysayers claim you can’t go as fast or as far in electric aircraft as you can in traditional aircraft, but we want to show it’s apples to apples.”

Another goal of the mission is to educate the next generation of innovators. Helios Horizon intern Jack Dowd, 21, “helps with anything needed,” says Merino. Dowd is studying aerospace engineering at the University of Central Florida and has helped build a custom stand to hold the test motor that’s slated for use on the plane. He’s also working on telemetry data.

“This is a very special and unique opportunity for Florida, Sarasota and our country,” says Chet Culver, the former governor of Iowa and a longtime clean energy advocate who is a supporter of Helios Horizon and has a winter home in Sarasota. “We replaced more than half of coal, oil and gas with wind power in Iowa. Now we can move toward another breakthrough in clean energy in our backyard.”

“Sustainability is, arguably, the most important thing for our future,” Culver continues. “We’ll continue to need oil and gas, but if we can supplement those conventional types with renewables, it’s a win-win for everyone.”

Iturmendi echoes Culver’s sentiments. “The reward is for something bigger than me: transitioning into the electrification of society,” he says. “Someone has to do it first. This is just part of who I am.”