Can electric air taxis carry passengers? Vertical Aerospace’s VX4 has just passed a key test

On the morning of April 14, 2026, at Cotswold Airport in southwest England, a test pilot flew straight into the air. He was testing the VX4, a electric vertical takeoff and landing (eVTOL), or air taxi, built by the British company Vertical Aerospace. In testing, the VX4’s eight propellers lifted it like a drone. Then the four front propellers tilted forward and the plane accelerated, no longer hanging on its rotors like a helicopter but cruising on its wings. like a small plane. Moments later, the sequence was reversed: the propellers raised and the plane decelerated, returned to a hover, and landed vertically on the same platform it had left.

In completing this test, Vertical, founded in 2016 and based in Bristol, accomplished one of the most difficult feats in eVTOL development: its prototype went from flying like a helicopter to flying like a planethen back. But a prototype is allowed to fly because a regulator agreed it was safe enough to test. A certified salesperson aircraftmeanwhile, must be safe enough for strangers to attach their children to.

Vertical is one of the first Western developers to demonstrate controlled transitionbut the April flight also counts because of the regulatory context. Other developers have flown in to prove the technology works; Vertical is trying to build a case in favor of certification. “The significance of this flight is that it was conducted in a way that aligned with the certification pathway from the outset,” says David King, Vertical’s chief engineer. In other words, Vertical comes close to the real business of running an air taxi company.

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King’s journey to eVTOLs began with his work at Boeing in 1989, on a military aircraft called the V-22 Osprey. The Osprey was the first production tiltrotor, an aircraft with propellers that could rotate on their mounts, pointing upward for vertical takeoff and tilting forward for horizontal flight. For most of the next three decades, at Bell and then at the Italian aerospace company Leonardo, King worked on civilian tiltrotors, the Osprey’s passenger-carrying cousins.

King decided to join Vertical in 2023 because the VX4 is essentially a tiltrotor with electric motors. “The beauty of the tiltrotor is that it takes you less than a minute from the time you apply power to cruising on one wing,” he says. “The fundamental magic of being able to move from a push position to a wing position is proven.” All that remains is to tune the system to transport different loads in varying weather conditions and on different routes.

Daniel Pleffken, an assistant professor at Embry-Riddle Aeronautical University in Florida who specializes in aircraft certification, is more measured about what the flight proves. “A successful flight shows that something can work,” he says. “Certification requires proving that it operates safely, consistently and under all expected conditions.” The plane must still accumulate evidence from failure tests, repeated flights and design reviews before regulators will clear it to carry passengers.

Vertical’s situation is unusual. Since 2023, the UK Civil Aviation Authority (CAA) has overseen every VX4 test flight. Most eVTOL companies fly their prototypes under a research flight license, but the data they produce does not count toward certification. Vertical flights are part of an agreement that has been accumulating evidence for certification for three years. “We are demonstrating to the regulator that we have the engineering capability, design assurance processes and internal governance required for full type certification,” King said.

The two other Western developers that have made piloted transitions, California-based Joby Aviation and Vermont-based BETA Technologies, did so under the U.S. Federal Aviation Administration’s (FAA) experimental permit system. Chinese developers have moved faster – EHang received the world’s first eVTOL type certificate from Chinese regulators in 2023 – but within a regulatory framework that Western airlines and aviation authorities do not consider equivalent. An experimental permit allows you to fly but does not constitute the same certification file. The European Union Aviation Safety Agency (EASA), whose eVTOL rules were adopted by the CAA, has developed a single new rulebook. The FAA, on the other hand, certifies eVTOLs by putting together written rules for small planes and helicopters. The European framework “is generally clearer because it was designed specifically for this class of aircraft,” explains Pleffken.

But clarity, Pleffken points out, is not the same thing as leniency. “The FAA, CAA and EASA use different regulatory architectures, but the underlying safety intent is not necessarily weaker in one system than in another,” he says. The European system is simpler to use because its rulebook was written from the ground up for eVTOLs, but that makes it a clearer test to study for, not easier to pass. In other words, Vertical’s test flight counts because the company has been studying the right test for three years, with the proctor in the room.

Even certification would not solve the whole problem. An air taxi is just one piece of a transportation infrastructure that still barely exists. “The main constraint is increasingly the operational ecosystem, not just the aircraft,” says Pleffken. “Vertiports, charging infrastructure, airspace integration, pilot training, maintenance and operational procedures all need to mature together. If one element is lagging, the whole system is lagging.” Vertiports are specially designed takeoff and landing areas with loaders and air traffic coordination. These are essentially tiny airports sized for planes the size of a large SUV. Few were built. Air traffic rules for how dozens of these planes will share low-altitude urban airspace with helicopters, drones and each other are still being developed.

The issue of ecosystems is a specialty of Laurie Garrow, a professor at the Georgia Institute of Technology and co-director of the university’s Center for Urban and Regional Air Mobility. His research group has spent nearly a decade trying to answer the question that aerial demonstrations can’t answer: Will people actually pay to fly in these planes? The industry hasn’t even decided yet what an eVTOL should look like. Vertical’s VX4 is a tiltrotor, but competitors have built planes with separate propellers for lifting and cruising or with many small rotors arranged like a larger-scale drone. “eVTOL design is the Wild West right now,” Garrow says. “We’ve never done this before, so we don’t know which design will be best for given missions or situations.”

Vertical aims to achieve passenger certification from the CAA and EASA simultaneously by the end of 2028. The FAA would follow, reviewing the European findings and deciding whether to accept them for U.S. operations. For this final certificate, Vertical plans to build seven pre-production Valo aircraft, a new model similar to the VX4 but modified based on three years of flight test data.

Garrow also points out a problem that air taxi engineers can’t solve: competition on the ground. Self-driving cars are being operated commercially in some cities, and a relaxing and productive ride in a self-driving car competes for the same customer an eVTOL is trying to attract. “We are now putting our first autonomous ground vehicles into circulation,” she says. “Studies have shown that it’s much more relaxing and you can be much more productive to be in an autonomous ground vehicle. So you’re not willing to pay as much to be in an airplane or in an eVTOL.”

In a 2021 paper, Garrow and colleagues Ranked among top 40 U.S. metro areas for air taxi travel potential and found that about half of the trips the nation’s commuters could reasonably make by eVTOL are concentrated in six of these metros. This concentration suggests a narrower market than the industry’s pitch for urban commuters suggests. “My personal opinion is that we’re going to see some of the first use cases in tourism applications,” she says, “over Hawaiian volcanoes or the Grand Canyon, where we currently fly helicopters.” She compares the present moment to the years following the arrival of commercial jet engines. When airliners first took off, a trip from London to Tokyo took more than 24 hours and had up to 10 stopovers, she says, and fares, adjusted for inflation, were roughly equivalent to what a first-class ticket costs today. The technology was real. The market took time to build.