Alex Stoll, an aeronautical engineer instrumental in the design of Joby Aviation’s industry-leading S4 electric vertical-takeoff-and-landing (eVTOL) aircraft, has died in a car accident age 37. Acknowledged as one of the pioneers of electric flight, Stoll joined Joby from Stanford University in 2012 as the startup’s first full-time employee.

In a speech at the Vertical Flight Society’s Transformative Vertical Flight meeting in January 2020, Joby founder JoeBen Bevirt credited Stoll with changing the company’s approach to eVTOL design by building a comprehensive system-optimization model with the goal of minimizing the cost per passenger mile.

This model allowed Joby to optimize every parameter for the aircraft. This led to the design evolving from the single-seat tiltwing Monarch concept through the two-seat S2 with eight tilting and folding propellers to the piloted, four-passenger S4 now in flight testing with its six tilting propellers.

“Alex had worked at Joby for more than a decade, playing a hugely significant role in the design of our aircraft and the definition of a company culture that continues to contribute to Joby’s success,” the company said in a statement.

At Stanford, Texas-born Stoll completed research into low-noise propellers for eVTOL aircraft. “It was Alex who inspired JoeBen and I to focus so much attention on noise,” Mark Moore, former NASA engineer and Uber Elevate co-founder, said in a Linkedin post. “Next to JoeBen, Alex is the reason why Joby has the best eVTOL aircraft.”

"We are deeply saddened by the loss of our beloved Alex Stoll, our colleague and a creative genius, who was not just an integral part of our team, but a cherished member of the Joby family," Joby CEO JoeBen Bevirt said in a statement. "Alex’s legacy will continue to inspire us as we strive to build upon the foundation has helped establish. We will channel our love for Alex into redoubling our efforts to realize his dream of transforming transportation.”