Joby Aviation’s Hybrid eVTOL Aircraft Completes Its First Uncrewed Transition From Hover to Steady Forward Flight

This week, footage of Joby Aviation’s S4-T eVTOL surfaced, demonstrating the aircraft’s seamless transition for a single uninterrupted flight. It lifted directly off the ground on its rotors, then switched a switch (figuratively speaking) and began relying on its wings for lift, gliding around without incident.

The S4-T, developed as a prototype by the engineers, is essentially an unmanned test vehicle based on the same design as Joby’s piloted electric air taxi. The S4-T has a turbine engine functioning alongside its electric motors to provide the extra juice it requires on longer trips, making it far more adaptable than a pure battery configuration, which might struggle with fuel efficiency at times. A huge positive is that they’ve kept so many things in common across the two versions, which has sped up progress significantly. The airframe, avionics, and flight controls are all the same, regardless of whether the power comes from batteries alone or a hybrid system. Any data collected by the aircraft during the flight is directly integrated into the passenger model, with no additional development effort required.

Efficiency is where the S4-T really shines, as we all know helicopters are notorious for burning a lot of fuel on those cruise segments, but the S4-T promises to be a lot more fuel-efficient once those wings are installed, and it will also fly faster, which is great news for future passengers and pilots. They should notice significantly less noise and shorter travel times between major city centers. Yesterday’s test focused on the problematic intermediate phase in which the aircraft transitions from vertical lift to wing-borne travel. Joby published the clip to signal the start of a new phase of dedicated runs targeted at refining that delicate transition, and it was a significant improvement over previous flights that had only hovered or moved forward slightly.

Work on the hybrid concept began at a breakneck speed from the start. It only took a few months last year for the first concepts to take flight, and they’ve kept up the pace ever since. Having shared systems across power options allows Joby to explore all sorts of new uses, such as military logistics or longer commercial routes, without having to build separate fleets.

Joby has already conducted piloted flights with its all-electric prototypes and intends to employ FAA test pilots on those aircraft in the coming weeks. Yesterday’s test result is only the latest piece of the puzzle to fall into place for regular vertical takeoff service, marking another step toward making vertical flight a reality in congested airspace. Each flight they complete narrows the distance between experimental runs and scheduled passenger service even further, and Joby continues to pile up these milestones, so the next ones are only waiting in the wings…
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