Whisper’s JetFoil Promises Near-VTOL at Half the Thrust

Whisper Aero says it has found a way to make its electric ducted fans lift an aircraft nearly vertically from a helipad-sized footprint while using about half the thrust a conventional eVTOL needs to hover, the Tennessee start-up announced today. Rather than take off straight up, a JetFoil aircraft rolls about 50 feet—far less than a conventional short takeoff and landing (STOL) aircraft needs—and lifts off within the same area a helicopter or eVTOL would use.

The capability comes from JetFoil, the company’s method of embedding a row of its ducted fans into the leading edge of a wing. Whisper revealed its JetFoil technology in 2023 as part of a nine-passenger regional aircraft concept called the Whisper Jet, and the following year, the company publicized a 100-seat electric airliner concept it dubbed the Whisper Jetliner, which packed 22 ducted fans into an upper-surface-blown wing. Both were fixed-wing designs for conventional or short takeoffs, not vertical flight.

Whisper’s fans exhaust a uniform sheet of air across the upper surface, and the company now says a single flap can deflect that sheet downward far enough to turn the aircraft’s thrust to near-vertical angles, without tilting the propulsion or adding separate lift rotors. Whisper Aero CEO Mark Moore revealed the concept on Tuesday at SAE AeroTech 2026 in West Palm Beach, Florida, where he accepted the AIAA F. E. Newbold V/STOL Award.

Moore told AIN that a true vertical takeoff forces an aircraft to a thrust-to-weight ratio of roughly 1.2, meaning it must generate more thrust than its own weight to leave the ground. JetFoil instead reaches flying speed in a short ground roll. Whisper calls the result “near-VTOL”—not a conventional STOL, the company argues, because the aircraft clears the same tight footprint a helicopter or eVTOL needs while requiring only about half the thrust a true vertical takeoff demands.

Although Whisper’s near-VTOL concept is technically capable of perfectly vertical takeoff and landing, it loses efficiency when doing so. “The whole point of this is to get two times more payload back with half the power,” Ian Villa, Whisper’s chief operating officer and chief product officer, told AIN. “That’s really why we call it near-VTOL.”

Moore framed it as a question of why bother hovering at all. With JetFoil, he said, “just scoot forward, and in less than 50 feet, you can climb and take off”—using the same ground footprint as a helicopter while carrying more payload.

A 1970s Idea Made Efficient

JetFoil builds on upper surface blowing, an aerodynamic concept NASA pioneered in the 1970s with its Quiet Short-Haul Research Aircraft, a demonstrator Moore worked on early in his career. That aircraft and the Boeing YC-14 blew engine exhaust over the wing to generate extra lift at low speeds, but both blew only a portion of the wing with hot, turbulent exhaust that limited how far the flow could be turned before it separated. Whisper says the cold, uniform exhaust from its electric ducted fans lets it blow the full span and turn the flow to far higher angles.

Bending the airflow relies on a principle of physics called the Coandă effect: a fast-moving stream of air tends to cling to a nearby curved surface instead of flying off in a straight line, the same way water runs down the back of a spoon held under a faucet. In a JetFoil wing, the air thrown back by the fans hugs the curved upper surface and follows it onto a flap. Angle the flap down, and the air bends with it, pushing the wing up—but only as long as the air keeps hugging the surface. If it peels away from the wing, that extra lift disappears. That is what defeated the 1970s aircraft at steep flap angles: their hot, turbulent exhaust broke away, while Whisper says its smooth, cooler stream clings far longer.

The same geometry has an acoustic payoff, the company says: because the fans sit in the wing’s leading edge and blow over the top, the wing shields the ground from much of their noise, reflecting it upward. Villa contrasted that with typical eVTOL designs that direct sound downward toward observers. Whisper says its propulsion is the quietest way yet devised to make thrust per pound, and that at full power in near-vertical takeoff it stays quieter than anything else flying.

In full-scale ground testing, Whisper said it turned the exhaust 90 degrees while retaining 96% of the thrust, and as far as 175 degrees with about 70% to 80% turning efficiency. “Nobody’s ever done this before, where they’re able to take that entire thrust vector of the aircraft and rotate it to any angle with no separation,” Moore said.

The company’s simulations show the blown wing reaching a maximum lift coefficient as high as 40 at 15 knots, an airspeed below the stall speed of most fixed-wing aircraft. “We achieve a stall-proof wing,” Moore said. “You can take this aircraft to any angle of attack, any orientation, and the wing will not stall and remain controllable.”

Tested, but Not Yet Flown

No JetFoil aircraft has yet flown in the new near-VTOL configuration, but Villa said the company has a demonstrator that has shown vertical takeoff capabilities on a test stand, with first flights expected within a few months. The flow-turning results come from a full-scale ground rig, and the high-lift figures are based on computational fluid dynamics rather than flight data. 

Separately, Whisper has been flight-testing an Aériane Swift 3 glider it plans to retrofit with its electric ducted fans, but as of this spring, those flights used the unmodified airframe carrying ballast to simulate the propulsion system’s weight; the powered retrofit is planned for later this year.

Whisper, which has said since its 2021 founding that it does not intend to build airframes, is positioning JetFoil as a propulsion-and-integration package for aircraft manufacturing partners it has so far declined to name on the civil side. On the defense side, Villa said the company’s Collaborative Logistics Aircraft family, funded through an Air Force strategic funding increase (STRATFI) agreement, uses JetFoil for STOL operations. Whisper revealed that uncrewed cargo aircraft family in May 2025.

When asked to compare the design to the similar-looking Lilium Jet, a German eVTOL whose developer ran out of money before reaching the market, Moore pointed out that JetFoil differs fundamentally because Lilium rotated its entire propulsion system to redirect thrust, while JetFoil turns only the airflow with a fixed flap. 

Whisper has not said what regulatory category it and its partners will pursue for a near-VTOL aircraft, a question that will shape how quickly the concept can reach service. Asked about the catch, Moore pointed to the difficulty of the engineering rather than any operational limit, saying it took the company five years to develop.

“We are in a new Wright Brothers era for V/STOL aircraft…and the technology is moving so quickly,” Moore said, calling JetFoil “a leapfrog technology that takes us to the next generation of eVTOL aircraft.”